Fundamentals of Physiology A Human Perspective (with CD-ROM and InfoTrac)

by Sherwood, Lauralee

• ISBN13: 9780534466978
• ISBN10: 0534466974
• Edition: 3rd
• Format: Paperback
• Copyright: 2005-03-30
• Publisher: Brooks Cole

Summary

FUNDAMENTALS OF PHYSIOLOGY, Third Edition, is based on Lauralee Sherwood's best selling Fifth Edition of HUMAN PHYSIOLOGY: FROM CELLS TO SYSTEMS. While both texts cover the same key topics in a current, engaging, and clinically relevant manner, FUNDAMENTALS OF PHYSIOLOGY is briefer, lower in level, and requires less of a background in chemistry, physics, and math than its sister text. Essential content is organized around the central theme of homeostasis, as demonstrated by the system-specific homeostatic model that opens each chapter, as well as the "Focus on Homeostasis" that completes each chapter. New to this edition are process-oriented figures, created to aid today's visual learners. These figures include step-by-step descriptions summarizing and integrating various aspects of essential concepts. Another noteworthy addition is the comparative and early introduction of "Principles of Neural and Hormonal Communication"-a NEW Chapter 4. This edition also showcases an emphasis on real-life experiences, using analogies as well as new "Clinical Note" icons, which flag clinically relevant material. The text is also supported by PhysioEdge 2-arguably the best student CD-ROM on the market-which ties concepts and art together with narration and animation. This free CD-ROM has been revised to include new media exercises and tutorials, and is integrated with this Third Edition to encourage students make optimal use of the available media. Instructors are likely to find indispensable our Multimedia Manager with Instructor Resources-a CD containing ALL line art from the text, over 40 animations, electronic versions of instructor materials, and Microsoft? PowerPoint? lectures.

Table of Contents

Homeostasis: The Foundation of Physiology	1	(17)
Introduction to Physiology	1	(1)
Levels of Organization in the Body	1	(6)
The chemical level: Various atoms and molecules make up the body	1	(1)
The cellular level: Cells are the basic units of life	2	(1)
The tissue level: Tissues are groups of cells of similar specialization	3	(1)
The organ level: An organ is a unit made up of several tissue types	4	(1)
The body system level: A body system is a collection of related organs	5	(1)
Beyond the Basics: Stem-Cell Science and Tissue Engineering: The Quest to Make Defective Body Parts Like New Again	6	(1)
The organism level: The body systems are packaged together into a functional whole body	6	(1)
Concept of Homeostasis	7	(5)
Body cells are in contact with a privately maintained internal environment	8	(1)
Body systems maintain homeostasis, a dynamic steady state in the internal environment	8	(4)
Homeostatic Control Systems	12	(6)
Homeostatic control systems may operate locally or bodywide	12	(1)
Negative feedback opposes an initial change and is widely used to maintain homeostasis	13	(1)
Positive feedback amplifies an initial change	13	(1)
Feedforward mechanisms initiate responses in anticipation of a change	14	(1)
Disruptions in homeostasis can lead to illness and death	15	(1)
Chapter in Perspective: Focus on Homeostasis	15	(1)
Chapter Summary	15	(1)
Chapter Review Exercises	16	(1)
Points to Ponder	17	(1)
Clinical Consideration	17	(1)
PhysioEdge Resources	17	(1)
Cell Physiology	18	(24)
Observations of Cells	19	(1)
An Overview of Cell Structure	20	(1)
The plasma membrane bounds the cell	20	(1)
The nucleus contains the DNA	20	(1)
The cytoplasm consists of various organelles and the cytosol	20	(1)
Endoplasmic Reticulum and Segregated Synthesis	21	(1)
The rough endoplasmic reticulum synthesizes proteins for secretion and membrane construction	21	(1)
The smooth endoplasmic reticulum packages new proteins in transport vesicles	22	(1)
Golgi Complex and Exocytosis	22	(2)
Transport vesicles carry their cargo to the Golgi complex for further processing	23	(1)
The Golgi complex packages secretory vesicles for release by exocytosis	24	(1)
Lysosomes and Endocytosis	24	(2)
Lysosomes serve as the intracellular digestive system	24	(1)
Extracellular material is brought into the cell by phagocytosis for attack by lysosomal enzymes	25	(1)
Lysosomes remove useless but not useful parts of the cell	26	(1)
Peroxisomes and Detoxification	26	(1)
Peroxisomes house oxidative enzymes that detoxify various wastes	26	(1)
Mitochondria and ATP Production	26	(6)
Mitochondria, the energy organelles, are enclosed by a double membrane	26	(1)
Mitochondria play a major role in generating ATP	27	(2)
The cell generates more energy in aerobic than in anaerobic conditions	29	(3)
Beyond the Basics: Aerobic Exercise: What For and How Much?	32	(1)
The energy stored within ATP is used for synthesis, transport, and mechanical work	32	(1)
Vaults as Cellular Trucks	32	(1)
Vaults may serve as cellular transport vehicles	32	(1)
Cytosol: Cell Gel	33	(1)
The cytosol is important in intermediary metabolism, ribosomal protein synthesis, and nutrient storage	33	(1)
Cytoskeleton: Cell ``Bone and Muscle''	34	(8)
Microtubules help maintain asymmetric cell shapes and play a role in complex cell movements	34	(2)
Microfilaments are important to cell contractile systems and as mechanical stiffeners	36	(1)
Intermediate filaments are important in cell regions subject to mechanical stress	37	(1)
The cytoskeleton functions as an integrated whole and links other parts of the cell together	37	(1)
Chapter in Perspective: Focus on Homeostasis	38	(1)
Chapter Summary	38	(1)
Chapter Review Exercises	39	(1)
Points to Ponder	40	(1)
Clinical Consideration	40	(1)
PhysioEdge Resources	41	(1)
The Plasma Membrane and Membrane Potential	42	(28)
Membrane Structure and Composition	43	(4)
The plasma membrane is a fluid lipid bilayer embedded with proteins	44	(2)
The lipid bilayer forms the basic structural barrier that encloses the cell	46	(1)
The membrane proteins perform a variety of specific membrane functions	46	(1)
The membrane carbohydrates serve as self-identity markers	46	(1)
Beyond the Basics: Cystic Fibrosis: A Fatal Defect in Membrane Transport	47	(1)
Cell-to-Cell Adhesions	47	(3)
The extracellular matrix serves as the biological ``glue.''	48	(1)
Some cells are directly linked together by specialized cell junctions	48	(2)
Overview of Membrane Transport	50	(1)
Unassisted Membrane Transport	50	(5)
Particles that can permeate the membrane passively diffuse down their concentration gradient	50	(2)
Ions that can permeate the membrane also passively move along their electrical gradient	52	(1)
Osmosis is the net diffusion of water down its own concentration gradient	52	(3)
Assisted Membrane Transport	55	(6)
Carrier-mediated transport is accomplished by a membrane carrier flipping its shape	55	(2)
Carrier-mediated transport may be passive or active	57	(2)
With vesicular transport, material is moved into or out of the cell wrapped in membrane	59	(2)
Membrane Potential	61	(9)
Membrane potential is a separation of opposite charges across the plasma membrane	61	(1)
Membrane potential is due to differences in the concentration and permeability of key ions	61	(5)
Chapter in Perspective: Focus on Homeostasis	66	(1)
Chapter Summary	66	(1)
Chapter Review Exercises	67	(1)
Points to Ponder	68	(1)
Clinical Consideration	69	(1)
PhysioEdge Resources	69	(1)
Principles of Neural and Hormonal Communication	70	(38)
Introduction to Neural Communication	71	(2)
Nerve and muscle are excitable tissues	71	(1)
Membrane potential decreases during depolarization and increases during hyperpolarization	72	(1)
Electrical signals are produced by changes in ion movement across the plasma membrane	72	(1)
Graded Potentials	73	(2)
The stronger a triggering event, the larger the resultant graded potential	73	(1)
Graded potentials spread by passive current flow	73	(1)
Graded potentials die out over short distances	73	(2)
Action Potentials	75	(10)
During an action potential, the membrane potential rapidly, transiently reverses	75	(1)
Marked changes in membrane permeability and ion movement lead to an action potential	76	(2)
The Na+ -K+ pump gradually restores the concentration gradients disrupted by action potentials	78	(1)
Action potentials are propagated from the axon hillock to the axon terminals	78	(2)
Once initiated, action potentials are conducted throughout a nerve fiber	80	(1)
The refractory period ensures one-way propagation of the action potential	80	(3)
Action potentials occur in all-or-none fashion	83	(1)
The strength of a stimulus is coded by the frequency of action potentials	83	(1)
Myelination increases the speed of conduction of action potentials	83	(2)
Synapses and Neuronal Integration	85	(7)
Synapses are junctions between presynaptic and postsynaptic neurons	85	(1)
A neurotransmitter carries the signal across a synapse	85	(1)
Some synapses excite whereas others inhibit the postsynaptic neuron	86	(2)
Each synapse is either always excitatory or always inhibitory	88	(1)
Neurotransmitters are quickly removed from the synaptic cleft	88	(1)
The grand postsynaptic potential depends on the sum of the activities of all presynaptic inputs	88	(2)
Action potentials are initiated at the axon hillock because it has the lowest threshold	90	(1)
Neuropeptides act primarily as neuromodulators	91	(1)
Drugs and diseases can modify synaptic transmission	91	(1)
Neurons are linked through complex converging and diverging pathways	92	(1)
Intercellular Communication and Signal Transduction	92	(3)
Communication between cells is largely orchestrated by extracellular chemical messengers	92	(2)
Extracellular chemical messengers bring about cell responses primarily by signal transduction	94	(1)
Some extracellular chemical messengers open chemically gated channels	94	(1)
Many extracellular messengers activate second-messenger pathways	94	(1)
Principles of Hormonal Communication	95	(7)
Hormones are chemically classified as being hydrophilic or lipophilic	95	(1)
The mechanisms of synthesis, storage, and secretion of hormones vary according to their chemical differences	95	(2)
Hydrophilic hormones dissolve in the plasma; lipophilic hormones are transported by plasma proteins	97	(1)
Hormones generally produce their effect by altering intracellular proteins	97	(1)
Hydrophilic hormones alter pre-existing proteins via second-messenger systems	98	(2)
Beyond the Basics: Programmed Cell Suicide: A Surprising Example of a Signal Transduction Pathway	100	(1)
By stimulating genes lipophilic hormones promote synthesis of new proteins	100	(2)
Hormonal responses are slower and longer than neural responses	102	(1)
Comparison of the Nervous and Endocrine Systems	102	(6)
The nervous system is ``wired'' and the endocrine system is ``wireless.''	103	(1)
Neural specificity is due to anatomic proximity and endocrine specificity to receptor specialization	103	(1)
The nervous and endocrine systems have their own realms of authority but interact functionally	103	(1)
Chapter in Perspective: Focus on Homeostasis	104	(1)
Chapter Summary	104	(2)
Chapter Review Exercises	106	(1)
Points to Ponder	107	(1)
Clinical Consideration	107	(1)
PhysioEdge Resources	107	(1)
The Central Nervous System	108	(36)
Organization of the Nervous System	110	(1)
The nervous system is organized into the central nervous system and the peripheral nervous system	110	(1)
The three functional classes of neurons are afferent neurons, efferent neurons, and interneurons	110	(1)
Protection and Nourishment of the Brain	111	(3)
Glial cells support the interneurons physically, metabolically, and functionally	111	(2)
The delicate central nervous tissue is well protected	113	(1)
Beyond the Basics: Strokes: A Deadly Domino Effect	114	(1)
The brain depends on constant delivery of oxygen and glucose by the blood	114	(1)
Overview of the Central Nervous System	114	(2)
Cerebral Cortex	116	(7)
The cerebral cortex is an outer shell of gray matter covering an inner core of white matter	117	(1)
The four pairs of lobes in the cerebral cortex are specialized for different activities	117	(2)
The parietal lobes accomplish somatosensory processing	119	(1)
The primary motor cortex is located in the frontal lobes	120	(1)
Other brain regions besides the primary motor cortex are important in motor control	120	(1)
Because of its plasticity, the brain can be remodeled in response to varying demands	121	(1)
Different regions of the cortex control different aspects of language	121	(1)
The association areas of the cortex are involved in many higher functions	122	(1)
The cerebral hemispheres have some degree of specialization	122	(1)
An electroencephalogram is a record of postsynaptic activity in cortical neurons	123	(1)
Basal Nuclei, Thalamus, and Hypothalamus	123	(3)
The basal nuclei play an important inhibitory role in motor control	123	(2)
The thalamus is a sensory relay station and is important in motor control	125	(1)
The hypothalamus regulates many homeostatic functions	125	(1)
The Limbic System and Its Functional Relations with the Higher Cortex	126	(4)
The limbic system plays a key role in emotion	126	(1)
The limbic system and higher cortex participate in controlling basic behavioral patterns	126	(1)
Motivated behaviors are goal directed	127	(1)
Norepinephrine, dopamine, and serotonin are neurotransmitters in pathways for emotions and behavior	127	(1)
Learning is the acquisition of knowledge as a result of experiences	128	(1)
Memory is laid down in stages	128	(1)
Memory traces are present in multiple regions of the brain	129	(1)
Short-term and long-term memory involve different molecular mechanisms	130	(1)
Cerebellum	130	(1)
The cerebellum is important in balance and in planning and executing voluntary movement	130	(1)
Brain Stem	131	(4)
The brain stem is a vital link between the spinal cord and higher brain regions	133	(1)
Sleep is an active process consisting of alternating periods of slow-wave and paradoxical sleep	133	(2)
The sleep-wake cycle is controlled by interactions among three neural systems	135	(1)
The function of sleep is unclear	135	(1)
Spinal Cord	135	(9)
The spinal cord extends through the vertebral canal and is connected to the spinal nerves	135	(1)
The white matter of the spinal cord is organized into tracts	136	(1)
Spinal nerves carry both afferent and efferent fibers	136	(1)
The spinal cord is responsible for the integration of many basic reflexes	137	(1)
Beyond the Basics: Swan Dive or Belly Flop: It's a Matter of CNS Control	138	(2)
Chapter in Perspective: Focus on Homeostasis	140	(1)
Chapter Summary	140	(2)
Chapter Review Exercises	142	(1)
Points to Ponder	142	(1)
Clinical Consideration	143	(1)
PhysioEdge Resources	143	(1)
The Peripheral Nervous System: Afferent Division; Special Senses	144	(40)
Introduction	145	(1)
Visceral afferents carry subconscious input whereas sensory afferents carry conscious input	145	(1)
Perception is the conscious awareness of surroundings derived from interpretation of sensory input	145	(1)
Receptor Physiology	146	(3)
Receptors have differential sensitivities to various stimuli	146	(1)
A stimulus alters the receptor's permeability, leading to a graded receptor potential	147	(1)
Receptor potentials may initiate action potentials in the afferent neuron	147	(1)
Receptors may adapt slowly or rapidly to sustained stimulation	148	(1)
Each somatosensory pathway is ``labeled'' according to modality and location	148	(1)
Acuity is influenced by receptive field size	148	(1)
Pain	149	(1)
Stimulation of nociceptors elicits the perception of pain plus motivational and emotional responses	149	(1)
The brain has a built-in analgesic system	150	(1)
Eye: Vision	150	(15)
Protective mechanisms help prevent eye injuries	150	(1)
Beyond the Basics: Acupuncture: Is It for Real?	151	(1)
The eye is a fluid-filled sphere enclosed by three specialized tissue layers	151	(1)
The amount of light entering the eye is controlled by the iris	152	(1)
The eye refracts the entering light to focus the image on the retina	153	(2)
Accommodation increases the strength of the lens for near vision	155	(3)
Light must pass through several retinal layers before reaching the photoreceptors	158	(1)
Phototransduction by retinal cells converts light stimuli into neural signals	159	(1)
Rods provide indistinct gray vision at night, whereas cones provide sharp color vision during the day	160	(1)
The sensitivity of the eyes can vary markedly through dark and light adaptation	161	(1)
Color vision depends on the ratios of stimulation of the three cone types	162	(1)
Visual information is separated before reaching the visual cortex	162	(1)
The thalamus and visual cortexes elaborate the visual message	163	(2)
Visual input goes to other areas of the brain not involved in vision perception	165	(1)
Ear: Hearing and Equilibrium	165	(10)
Sound waves consist of alternate regions of compression and rarefaction of air molecules	166	(1)
The external ear plays a role in sound localization	167	(1)
The tympanic membrane vibrates in unison with sound waves in the external ear	167	(1)
The middle ear bones convert tympanic-membrane vibrations into fluid movements in the inner ear	168	(1)
The cochlea contains the organ of Corti, the sense organ for hearing	169	(1)
Hair cells in the organ of Corti transduce fluid movements into neural signals	169	(1)
Pitch discrimination depends on the region of the basilar membrane that vibrates	169	(2)
Loudness discrimination depends on the amplitude of vibration	171	(1)
Deafness is caused by defects either in conduction or neural processing of sound waves	172	(1)
The vestibular apparatus is important for equilibrium by detecting position and motion of the head	172	(3)
Chemical Senses: Taste and Smell	175	(9)
Taste receptor cells are located primarily within tongue taste buds	175	(2)
Taste discrimination is coded by patterns of activity in various taste bud receptors	177	(1)
The olfactory receptors in the nose are specialized endings of renewable afferent neurons	178	(1)
Various parts of an odor are detected by different olfactory receptors and sorted into ``smell files.''	178	(1)
Odor discrimination is coded by patterns of activity in the olfactory bulb glomeruli	179	(1)
The olfactory system adapts quickly	179	(1)
The vomeronasal organ detects pheromones	179	(1)
Chapter in Perspective: Focus on Homeostasis	180	(1)
Chapter Summary	180	(2)
Chapter Review Exercises	182	(1)
Points to Ponder	183	(1)
Clinical Consideration	183	(1)
PhysioEdge Resources	183	(1)
The Peripheral Nervous System: Efferent Division	184	(18)
Introduction	185	(1)
Autonomic Nervous System	185	(7)
An autonomic nerve pathway consists of a two-neuron chain	185	(1)
Parasympathetic postganglionic fibers release acetylcholine; sympathetic ones release norepinephrine	186	(1)
The sympathetic and parasympathetic nervous systems dually innervate most visceral organs	186	(4)
The adrenal medulla is a modified part of the sympathetic nervous system	190	(1)
Several different receptor types are available for each autonomic neurotransmitter	190	(1)
Many regions of the central nervous system are involved in the control of autonomic activities	191	(1)
Somatic Nervous System	192	(10)
Motor neurons supply skeletal muscle	192	(1)
Motor neurons are the final common pathway	192	(1)
Motor neurons and skeletal muscle fibers are chemically linked at neuromuscular junctions	193	(1)
Acetylcholine is the neuromuscular junction neurotransmitter	193	(2)
Acetylcholinesterase terminates acetylcholine activity at the neuromuscular junction	195	(2)
The neuromuscular junction is vulnerable to several chemical agents and diseases	197	(1)
Beyond the Basics: Botulinum Toxin's Reputation Gets a Facelift	198	(1)
Chapter in Perspective: Focus on Homeostasis	198	(1)
Chapter Summary	199	(1)
Chapter Review Exercises	199	(1)
Points to Ponder	200	(1)
Clinical Consideration	200	(1)
PhysioEdge Resources	201	(1)
Muscle Physiology	202	(38)
Introduction	203	(1)
Structure of Skeletal Muscle	204	(3)
Skeletal muscle fibers are striated by a highly organized internal arrangement	204	(1)
Myosin forms the thick filaments	204	(2)
Actin is the main structural component of the thin filaments	206	(1)
Molecular Basis of Skeletal Muscle Contraction	207	(6)
During contraction, cycles of cross-bridge binding and bending pull the thin filaments inward	207	(2)
Calcium is the link between excitation and contraction	209	(4)
Contractile activity far outlasts the electrical activity that initiated it	213	(1)
Skeletal Muscle Mechanics	213	(6)
Whole muscles are groups of muscle fibers bundled together and attached to bones	213	(1)
Contractions of a whole muscle can be of varying strength	214	(1)
The number of fibers contracting within a muscle depends on the extent of motor unit recruitment	214	(1)
The frequency of stimulation can influence the tension developed by each muscle fiber	214	(1)
Twitch summation results from a sustained elevation in cytosolic calcium	215	(1)
There is an optimal muscle length at which maximal tension can be developed	216	(1)
Muscle tension is transmitted to bone as the contractile component tightens the series-elastic component	217	(1)
The two primary types of contraction are isotonic and isometric	218	(1)
The velocity of shortening is related to the load	219	(1)
Skeletal Muscle Metabolism and Fiber Types	219	(4)
Muscle fibers have alternate pathways for forming ATP	219	(1)
Increased oxygen consumption is necessary to recover from exercise	220	(1)
There are three types of skeletal muscle fibers, based on differences in ATP hydrolysis and synthesis	220	(1)
Muscle fibers adapt considerably in response to the demands placed on them	221	(1)
Beyond the Basics: Are Athletes Who Use Steroids to Gain Competitive Advantage Really Winners or Losers?	222	(1)
Control of Motor Movement	223	(4)
Multiple neural inputs influence motor unit output	223	(1)
Beyond the Basics: Loss of Muscle Mass: A Plight of Space Flight	224	(1)
Muscle receptors provide afferent information needed to control skeletal muscle activity	225	(2)
Smooth and Cardiac Muscle	227	(13)
Smooth muscle cells are small and unstriated	227	(3)
Smooth muscle cells are turned on by Ca2+ -dependent phosphorylation of myosin	230	(1)
Multiunit smooth muscle is neurogenic	231	(1)
Single-unit smooth muscle cells form functional syncytia	231	(1)
Single-unit smooth muscle is myogenic	231	(1)
Gradation of single-unit smooth muscle contraction differs from that of skeletal muscle	232	(2)
Smooth muscle can still develop tension when stretched	234	(1)
Smooth muscle is slow and economical	234	(1)
Cardiac muscle blends features of both skeletal and smooth muscle	235	(1)
Chapter in Perspective: Focus on Homeostasis	235	(1)
Chapter Summary	236	(1)
Chapter Review Exercises	237	(1)
Points to Ponder	238	(1)
Clinical Consideration	239	(1)
PhysioEdge Resources	239	(1)
Cardiac Physiology	240	(34)
Introduction	241	(1)
Anatomy of the Heart	242	(4)
The heart is a dual pump	242	(2)
Pressure-operated heart valves ensure that blood flows in the right direction through the heart	244	(1)
The heart walls consist primarily of spirally arranged cardiac muscle fibers	245	(1)
Cardiac muscle fibers are interconnected by intercalated discs and form functional syncytia	245	(1)
Electrical Activity of the Heart	246	(9)
Cardiac autorhythmic cells display pacemaker activity	246	(1)
The sinoatrial node is the normal pacemaker of the heart	247	(2)
The spread of cardiac excitation is coordinated to ensure efficient pumping	249	(1)
The action potential of cardiac contractile cells shows a characteristic plateau	250	(1)
Ca2+ entry from the ECF induces a more abundant Ca2+ release from the sarcoplasmic reticulum	251	(1)
A long refractory period prevents tetanus of cardiac muscle	252	(1)
The ECG is a record of the overall spread of electrical activity through the heart	252	(1)
Different parts of the ECG record can be correlated to specific cardiac events	253	(1)
The ECG can be used to diagnose abnormal heart rates, arrhythmias, and damage of heart muscle	254	(1)
Mechanical Events of the Cardiac Cycle	255	(4)
The heart alternately contracts to empty and relaxes to fill	255	(3)
The two heart sounds are associated with valve closures	258	(1)
Turbulent blood flow produces heart murmurs	258	(1)
Cardiac Output and Its Control	259	(6)
Cardiac output depends on the heart rate and the stroke volume	259	(1)
Heart rate is determined primarily by autonomic influences on the SA node	259	(2)
Stroke volume is determined by the extent of venous return and by sympathetic activity	261	(1)
Increased end-diastolic volume results in increased stroke volume	261	(1)
Sympathetic stimulation increases the contractility of the heart	262	(2)
In heart failure the contractility of the heart decreases	264	(1)
Nourishing the Heart Muscle	265	(9)
The heart receives most of its own blood supply through the coronary circulation during diastole	265	(1)
Atherosclerotic coronary artery disease can deprive the heart of essential oxygen	265	(3)
Beyond the Basics: Atherosclerosis: Cholesterol and Beyond	268	(2)
Chapter in Perspective: Focus on Homeostasis	270	(1)
Chapter Summary	270	(1)
Chapter Review Exercises	271	(1)
Points to Ponder	272	(1)
Clinical Consideration	273	(1)
PhysioEdge Resources	273	(1)
The Blood Vessels and Blood Pressure	274	(40)
Introduction	275	(5)
To maintain homeostasis, reconditioning organs receive blood flow in excess of their own needs	275	(1)
Blood flow through vessels depends on the pressure gradient and vascular resistance	276	(2)
The vascular tree consists of arteries, arterioles, capillaries, venules, and veins	278	(1)
Beyond the Basics: From Humors to Harvey: Historical Highlights in Circulation	279	(1)
Arteries	280	(3)
Arteries serve as rapid-transit passageways to the organs and as a pressure reservoir	280	(1)
Arterial pressure fluctuates in relation to ventricular systole and diastole	280	(1)
Blood pressure can be measured indirectly by using a sphygmomanometer	281	(2)
Mean arterial pressure is the main driving force for blood flow	283	(1)
Arterioles	283	(6)
Arterioles are the major resistance vessels	283	(1)
Local control of arteriolar radius is important in determining the distribution of cardiac output	284	(1)
Local metabolic influences on arteriolar radius help match blood flow with the organs' needs	285	(2)
Local histamine release pathologically dilates arterioles	287	(1)
Local physical influences on arteriolar radius include temperature changes and stretch	287	(1)
Extrinsic sympathetic control of arteriolar radius in important in regulating blood pressure	288	(1)
The medullary cardiovascular control center and several hormones regulate blood pressure	289	(1)
Capillaries	289	(9)
Capillaries are ideally suited to serve as sites of exchange	289	(2)
Water-filled capillary pores permit passage of small, water-soluble substances	291	(2)
Interstitial fluid is a passive intermediary between blood and cells	293	(1)
Diffusion across the capillary walls is important in solute exchange	293	(1)
Bulk flow across the capillary walls is important in extracellular fluid distribution	293	(2)
The lymphatic system is an accessory route by which interstitial fluid can be returned to the blood	295	(2)
Edema occurs when too much interstitial fluid accumulates	297	(1)
Veins	298	(4)
Veins serve as a blood reservoir as well as passageways back to the heart	298	(1)
Venous return is enhanced by a number of extrinsic factors	299	(3)
Blood Pressure	302	(12)
Blood pressure is regulated by controlling cardiac output, total peripheral resistance, and blood volume	303	(2)
The baroreceptor reflex is an important short-term mechanism for regulating blood pressure	305	(1)
Hypertension is a serious national public health problem, but its causes are largely unknown	306	(2)
Orthostatic hypotension results from transient inadequate sympathetic activity	308	(1)
Circulatory shock can become irreversible	308	(2)
Chapter in Perspective: Focus on Homeostasis	310	(1)
Chapter Summary	310	(2)
Chapter Review Exercises	312	(1)
Points to Ponder	313	(1)
Clinical Consideration	313	(1)
PhysioEdge Resources	313	(1)
The Blood and Body Defenses	314	(50)
Introduction	315	(1)
Plasma	315	(2)
Plasma water is a transport medium for many inorganic and organic substances	316	(1)
Many of the functions of plasma are carried out by plasma proteins	316	(1)
Erythrocytes	317	(4)
The structure of erythrocytes is well suited to their main function of O2 transport in the blood	317	(1)
The bone marrow continuously replaces worn-out erythrocytes	318	(1)
Erythropoiesis is controlled by erythropoietin from the kidneys	318	(1)
Anemia can be caused by a variety of disorders	319	(1)
Beyond the Basics: Blood Doping: Is More of a Good Thing Better?	320	(1)
Polycythemia is an excess of circulating erythrocytes	320	(1)
Platelets and Hemostasis	321	(5)
Platelets are cell fragments shed from megakaryocytes	321	(1)
Hemostasis prevents blood loss from damaged small vessels	321	(1)
Vascular spasm reduces blood flow through an injured vessel	322	(1)
Platelets aggregate to form a plug at a vessel tear or cut	322	(1)
Clot formation results from a triggered chain reaction involving plasma clotting factors	323	(2)
Fibrinolytic plasmin dissolves clots	325	(1)
Inappropriate clotting produces thromboembolism	325	(1)
Hemophilia is the primary condition that produces excessive bleeding	326	(1)
Leukocytes	326	(4)
Pathogenic bacteria and viruses are the major targets of the immune system	326	(1)
There are five types of leukocytes	326	(1)
Leukocytes are produced at varying rates depending on the changing defense needs of the body	327	(2)
Immune responses may be either innate and nonspecific, or adaptive and specific	329	(1)
Innate Immunity	330	(5)
Inflammation is a nonspecific response to foreign invasion or tissue damage	330	(3)
NSAIDS and glucocorticoid drugs suppress the inflammatory response	333	(1)
Interferon transiently inhibits multiplication of viruses in most cells	333	(1)
Natural killer cells destroy virus-infected cells and cancer cells on first exposure to them	334	(1)
The complement system punches holes in micro-organisms	334	(1)
Adaptive Immunity: General Concepts	335	(1)
Adaptive immune responses include antibody-mediated immunity and cell-mediated immunity	335	(1)
An antigen induces an immune response against itself	336	(1)
B Lymphocytes: Antibody-Mediated Immunity	336	(9)
Antigens stimulate B cells to convert into plasma cells that produce antibodies	336	(1)
Antibodies are Y-shaped and classified according to properties of their tail portion	337	(1)
Antibodies largely amplify innate immune responses to promote antigen destruction	338	(1)
Clonal selection accounts for the specificity of antibody production	338	(2)
Selected clones differentiate into active plasma cells and dormant memory cells	340	(1)
Blood types are a form of natural immunity	341	(2)
Beyond the Basics: Vaccination: A Victory Over Many Dreaded Diseases	343	(1)
Lymphocytes respond only to antigen presented to them by antigen-presenting cells	344	(1)
T Lymphocytes: Cell-Mediated Immunity	345	(7)
T cells bind directly with their targets	345	(1)
The two types of T cells are cytotoxic T cells and helper T cells	346	(1)
Cytotoxic T cells secrete chemicals that destroy target cells	347	(2)
Helper T cells secrete chemicals that amplify the activity of other immune cells	349	(1)
The immune system is normally tolerant of self-antigens	350	(1)
The major histocompatibility complex is the code for self-antigens	350	(1)
Immune surveillance against cancer cells involves an interplay among immune cells and interferon	351	(1)
Immune Diseases	352	(3)
Immune deficiency diseases result from insufficient immune responses	352	(1)
Allergies are inappropriate immune attacks against harmless environmental substances	353	(2)
External Defenses	355	(9)
The skin consists of an outer protective epidermis and an inner, connective tissue dermis	355	(1)
Specialized cells in the epidermis produce keratin and melanin and participate in immune defense	356	(1)
Protective measures within body cavities discourage pathogen invasion into the body	357	(1)
Chapter in Perspective: Focus on Homeostasis	358	(1)
Chapter Summary	359	(2)
Chapter Review Exercises	361	(1)
Points to Ponder	362	(1)
Clinical Consideration	362	(1)
PhysioEdge Resources	363	(1)
The Respiratory System	364	(40)
Introduction	365	(4)
The respiratory system does not participate in all steps in respiration	365	(1)
The respiratory airways conduct air between the atmosphere and alveoli	366	(1)
The gas-exchanging alveoli are thin-walled, inflatable sacs encircled by pulmonary capillaries	367	(1)
The lungs occupy much of the thoracic cavity	368	(1)
A pleural sac separates each lung from the thoracic wall	369	(1)
Respiratory Mechanics	369	(14)
Interrelationships among pressures inside and outside the lungs are important in ventilation	369	(1)
The lungs are normally stretched to fill the larger thorax	370	(1)
Flow of air into and out of the lungs occurs because of cyclic changes in intra-alveolar pressure	371	(2)
Airway resistance influences airflow rates	373	(3)
Airway resistance is abnormally increased with chronic obstructive pulmonary disease	376	(1)
Elastic behavior of the lungs is due to elastic connective tissue and alveolar surface tension	377	(1)
Pulmonary surfactant decreases surface tension and contributes to lung stability	377	(2)
The lungs normally operate at about ``half full.''	379	(1)
Alveolar ventilation is less than pulmonary ventilation because of dead space	380	(3)
Gas Exchange	383	(4)
Gases move down partial pressure gradients	383	(1)
Oxygen enters and CO2 leaves the blood in the lungs passively down partial pressure gradients	384	(1)
Factors other than the partial pressure gradient influence the rate of gas transfer	385	(1)
Gas exchange across the systemic capillaries also occurs down partial pressure gradients	386	(1)
Gas Transport	387	(7)
Most O2 in the blood is transported bound to hemoglobin	387	(1)
The PO2 is the primary factor determining the percent hemoglobin saturation	387	(2)
Hemoglobin promotes the net transfer of O2 at both the alveolar and tissue levels	389	(1)
Factors at the tissue level promote the unloading of O2 from hemoglobin	390	(1)
Hemoglobin has a much higher affinity for carbon monoxide than for O2	391	(1)
Most CO2 is transported in the blood as bicarbonate	391	(1)
Various respiratory states are characterized by abnormal blood-gas levels	392	(2)
Beyond the Basics: Effects of Heights and Depths on the Body	394	(1)
Control of Respiration	394	(10)
Respiratory centers in the brain stem establish a rhythmic breathing pattern	394	(2)
The magnitude of ventilation is adjusted in response to three chemical factors: PO2, PCO2, and H+	396	(1)
Decreased arterial PO2 increases ventilation only as an emergency mechanism	397	(1)
Carbon dioxide-generated H+ in the brain is normally the main regulator of ventilation	398	(1)
Adjustments in ventilation in response to changes in arterial H+ are important in acid-base balance	399	(1)
During apnea, a person ``forgets to breathe''; during dyspnea, a person feels ``short of breath.''	399	(1)
Chapter in Perspective: Focus on Homeostasis	400	(1)
Chapter Summary	400	(2)
Chapter Review Exercises	402	(1)
Points to Ponder	403	(1)
Clinical Consideration	403	(1)
PhysioEdge Resources	403	(1)
The Urinary System	404	(38)
Introduction	405	(6)
The kidneys perform a variety of functions aimed at maintaining homeostasis	405	(1)
The kidneys form the urine; the rest of the urinary system carries the urine to the outside	406	(1)
The nephron is the functional unit of the kidney	406	(2)
The three basic renal processes are glomerular filtration, tubular reabsorption, and tubular secretion	408	(3)
Glomerular Filtration	411	(3)
Glomerular capillary blood pressure is the major force that induces glomerular filtration	411	(1)
Changes in the GFR primarily result from changes in glomerular capillary blood pressure	412	(2)
The kidneys normally receive 20 to 25% of the cardiac output	414	(1)
Tubular Reabsorption	414	(8)
Tubular reabsorption is tremendous, highly selective, and variable	414	(1)
Tubular reabsorption involves transepithelial transport	415	(1)
An active Na+ -K+ ATPase pump in the basolateral membrane is essential for Na+ reabsorption	415	(1)
Aldosterone stimulates Na+ reabsorption in the distal and collecting tubules	416	(2)
Atrial natriuretic peptide inhibits Na+ reabsorption	418	(1)
Giucose and amino acids are reabsorbed by Na+ -dependent secondary active transport	419	(1)
In general, actively reabsorbed substances exhibit a tubular maximum	419	(1)
Glucose is an example of an actively reabsorbed substance that is not regulated by the kidneys	419	(1)
Phosphate is an example of an actively reabsorbed substance that is regulated by the kidneys	420	(1)
Active Na+ reabsorption is responsible for the passive reabsorption of Cl-, H2O, and urea	421	(1)
In general, unwanted waste products are not reabsorbed	422	(1)
Tubular Secretion	422	(2)
Hydrogen ion secretion is important in acid--base balance	422	(1)
Potassium secretion is controlled by aldosterone	422	(1)
Organic anion and cation secretion helps efficiently eliminate foreign compounds from the body	423	(1)
Urine Excretion and Plasma Clearance	424	(18)
Plasma clearance is the volume of plasma cleared of a particular substance per minute	424	(1)
If a substance is filtered but not reabsorbed or secreted, its plasma clearance rate equals the GFR	425	(1)
If a substance is filtered and reabsorbed but not secreted, its plasma clearance rate is always less than the GFR	425	(1)
If a substance is filtered and secreted but not reabsorbed, its plasma clearance rate is always greater than the GFR	425	(2)
The kidneys can excrete urine of varying concentrations depending on the body's state of hydration	427	(1)
The medullary vertical osmotic gradient is established by countercurrent multiplication	427	(2)
Vasopressin-controlled, variable H2O reabsorption occurs in the final tubular segments	429	(6)
Beyond the Basics: Dialysis: Cellophane Tubing or Abdominal Lining as an Artificial Kidney	435	(1)
Renal failure has wide-ranging consequences	435	(1)
Urine is temporarily stored in the bladder, from which it is emptied by micturition	436	(1)
Chapter in Perspective: Focus on Homeostasis	437	(1)
Chapter Summary	438	(1)
Chapter Review Exercises	439	(1)
Points to Ponder	440	(1)
Clinical Consideration	440	(1)
PhysioEdge Resources	441	(1)
Fluid and Acid--Base Balance	442	(22)
Balance Concept	443	(1)
The internal pool of a substance is the amount of that substance in the ECF	443	(1)
To maintain stable balance of an ECF constituent, its input must equal its output	444	(1)
Fluid Balance	444	(9)
Body water is distributed between the ICF and ECF compartments	444	(1)
The plasma and interstitial fluid are similar in composition, but the ECF and ICF differ markedly	445	(1)
Fluid balance is maintained by regulating ECF volume and osmolarity	445	(1)
Controlling ECF volume is important in the long-term regulation of blood pressure	446	(1)
Controlling salt balance is primarily important in regulating ECF volume	447	(1)
Controlling ECF osmolarity prevents changes in ICF volume	448	(1)
Beyond the Basics: A Potentially Fatal Clash: When Exercising Muscles and Cooling Mechanisms Compete for an Inadequate Plasma Volume	449	(1)
During ECF hypertonicity, the cells shrink as H2O leaves them	449	(1)
During ECF hypotonicity, the cells swell as H2O enters them	450	(1)
Controlling water balance by means of vasopressin is important in regulating ECF osmolarity	450	(2)
Vasopressin secretion and thirst are largely triggered simultaneously	452	(1)
Acid--Base Balance	453	(11)
Acids liberate free hydrogen ions, whereas bases accept them	453	(1)
The pH designation is used to express [H+]	454	(1)
Fluctuations in [H+] alter nerve, enzyme, and K+ activity	455	(1)
Hydrogen ions are continually added to the body fluids as a result of metabolic activities	455	(1)
Chemical buffer systems minimize changes in pH by binding with or yielding free H+	456	(1)
The H2CO3:HCO3-buffer pair is the primary ECF buffer for noncarbonic acids	457	(1)
The protein buffer system is primarily important intracellularly	457	(1)
The hemoglobin buffer system buffers H+ generated from carbonic acid	457	(1)
The phosphate buffer system is an important urinary buffer	457	(1)
Chemical buffer systems act as the first line of defense against changes in [H+]	457	(1)
The respiratory system regulates [H+] by controlling the rate of CO2 removal	458	(1)
The respiratory system serves as the second line of defense against changes in [H+]	458	(1)
The kidneys help maintain acid--base balance by adjusting their rate of H+ excretion, HCO3 - excretion, and NH3 secretion	458	(2)
The kidneys are a powerful third line of defense against changes in [H+]	460	(1)
Acid--base imbalances can arise from either respiratory dysfunction or metabolic disturbances	460	(1)
Chapter in Perspective: Focus on Homeostasis	461	(1)
Chapter Summary	461	(1)
Chapter Review Exercises	462	(1)
Points to Ponder	463	(1)
Clinical Consideration	463	(1)
PhysioEdge Resources	463	(1)
The Digestive System	464	(46)
Introduction	465	(6)
The digestive system performs four basic digestive processes	465	(2)
The digestive tract and accessory digestive organs make up the digestive system	467	(1)
The digestive tract wall has four layers	467	(2)
Regulation of digestive function is complex and synergistic	469	(2)
Receptor activation alters digestive activity through neural reflexes and hormonal pathways	471	(1)
Mouth	471	(2)
The oral cavity is the entrance to the digestive tract	471	(1)
The teeth do the chewing	472	(1)
Saliva begins carbohydrate digestion, is important in oral hygiene, and facilitates speech	472	(1)
Salivary secretion is continuous and can be reflexly increased	472	(1)
Digestion in the mouth is minimal; no absorption of nutrients occurs	473	(1)
Pharynx and Esophagus	473	(2)
Swallowing is a sequentially programmed all-or-none reflex	473	(1)
During the oropharyngeal stage of swallowing, food is prevented from entering the wrong passageways	474	(1)
The pharyngoesophageal sphincter prevents air from entering the digestive tract during breathing	474	(1)
Peristaltic waves push food through the esophagus	475	(1)
The gastroesophageal sphincter prevents reflux of gastric contents	475	(1)
Esophageal secretion is entirely protective	475	(1)
Stomach	475	(11)
The stomach stores food and begins protein digestion	476	(1)
Gastric filling involves receptive relaxation	476	(1)
Gastric storage takes place in the body of the stomach	476	(1)
Gastric mixing takes place in the antrum of the stomach	476	(1)
Gastric emptying is largely controlled by factors in the duodenum	477	(2)
Emotions can influence gastric motility	479	(1)
The stomach does not actively participate in vomiting	479	(2)
Gastric digestive juice is secreted by glands located at the base of gastric pits	481	(1)
Hydrochloric acid activates pepsinogen	481	(1)
Pepsinogen, once activated, begins protein digestion	481	(1)
Mucus is protective	481	(1)
Intrinsic factor is essential for absorption of vitamin B12	482	(1)
Multiple regulatory pathways influence the parietal and chief cells	482	(1)
Control of gastric secretion involves three phases	482	(1)
Gastric secretion gradually decreases as food empties from the stomach into the intestine	483	(1)
The gastric mucosal barrier protects the stomach lining from gastric secretions	484	(1)
Beyond the Basics: Ulcers: When Bugs Break the Barrier	485	(1)
Carbohydrate digestion continues in the body of the stomach; protein digestion begins in the antrum	486	(1)
The stomach absorbs alcohol and aspirin but no food	486	(1)
Pancreatic and Biliary Secretions	486	(7)
The pancreas is a mixture of exocrine and endocrine tissue	486	(1)
The exocrine pancreas secretes digestive enzymes and an aqueous alkaline fluid	486	(2)
Pancreatic exocrine secretion is regulated by secretin and CCK	488	(1)
The liver performs various important functions including bile production	488	(1)
The liver lobules are delineated by vascular and bile channels	489	(1)
Bile is continuously secreted by the liver and is diverted to the gallbladder between meals	489	(1)
Bile salts are recycled through the enterohepatic circulation	490	(1)
Bile salts aid fat digestion and absorption	491	(1)
Bilirubin is a waste product excreted in the bile	492	(1)
Bile salts are the most potent stimulus for increased bile secretion	492	(1)
The gallbladder stores and concentrates bile between meals and empties during meals	493	(1)
Small Intestine	493	(9)
Segmentation contractions mix and slowly propel the chyme	493	(1)
The migrating motility complex sweeps the intestine clean between meals	494	(1)
The ileocecal juncture prevents contamination of the small intestine by colonic bacteria	494	(1)
Small-intestine secretions do not contain any digestive enzymes	494	(1)
The small-intestine enzymes complete digestion intracellularly	495	(1)
The small intestine is remarkably well adapted for its primary role in absorption	495	(3)
The mucosal lining experiences rapid turnover	498	(1)
Special mechanisms facilitate absorption of most nutrients	498	(3)
Most absorbed nutrients immediately pass through the liver for processing	501	(1)
Extensive absorption by the small intestine keeps pace with secretion	501	(1)
Diarrhea results in loss of fluid and electrolytes	501	(1)
Large Intestine	502	(2)
The large intestine is primarily a drying and storage organ	502	(1)
Haustral contractions slowly shuffle the colonic contents back and forth	502	(1)
Mass movements propel colonic contents long distances	502	(1)
Feces are eliminated by the defecation reflex	503	(1)
Constipation occurs when the feces become too dry	503	(1)
Large-intestine secretion is entirely protective	503	(1)
The colon contains myriads of beneficial bacteria	503	(1)
The large intestine absorbs salt and water, converting the luminal contents into feces	503	(1)
Intestinal gases are absorbed or expelled	504	(1)
Overview of the Gastrointestinal Hormones	504	(6)
Chapter in Perspective: Focus on Homeostasis	505	(1)
Chapter Summary	505	(2)
Chapter Review Exercises	507	(1)
Points to Ponder	508	(1)
Clinical Consideration	508	(1)
PhysioEdge Resources	509	(1)
Energy Balance and Temperature Regulation	510	(18)
Energy Balance	511	(7)
Most food energy is ultimately converted into heat in the body	511	(1)
The metabolic rate is the rate of energy use	512	(1)
Energy input must equal energy output to maintain a neutral energy balance	513	(1)
Food intake is controlled primarily by the hypothalamus	514	(2)
Obesity occurs when more kilocalories are consumed than are burned up	516	(1)
Beyond the Basics: What the Scales Don't Tell You	517	(1)
People suffering from anorexia nervosa have a pathologic fear of gaining weight	517	(1)
Temperature Regulation	518	(10)
Internal core temperature is homeostatically maintained at 100°F	518	(1)
Heat input must balance heat output to maintain a stable core temperature	518	(1)
Heat exchange takes place by radiation, conduction, convection, and evaporation	519	(1)
The hypothalamus integrates a multitude of thermosensory inputs	520	(1)
Shivering is the primary involuntary means of increasing heat production	520	(1)
The magnitude of heat loss can be adjusted by varying the flow of blood through the skin	521	(1)
Beyond the Basics: The Extremes of Heat and Cold Can Be Fatal	522	(1)
The hypothalamus simultaneously coordinates heat production and heat loss mechanisms	522	(1)
During a fever, the hypothalamic thermostat is ``reset'' at an elevated temperature	523	(1)
Chapter in Perspective: Focus on Homeostasis	524	(1)
Chapter Summary	524	(1)
Chapter Review Exercises	525	(1)
Points to Ponder	526	(1)
Clinical Consideration	526	(1)
PhysioEdge Resources	527	(1)
The Endocrine System	528	(54)
General Principles of Endocrinology	529	(7)
Hormones exert a variety of regulatory effects throughout the body	530	(1)
The plasma concentration of a hormone is normally regulated by changes in its rate of secretion	530	(2)
The plasma concentration of a hormone is influenced by its rate of excretion	532	(1)
Endocrine disorders result from hormone excess or deficiency or decreased target-cell responsiveness	532	(1)
The responsiveness of a target cell can be varied by regulating the number of hormone-specific receptors	532	(4)
Pineal Gland and Circadian Rhythms	536	(1)
The suprachiasmatic nucleus is the master biological clock	536	(1)
Melatonin helps keep the body's circadian rhythms in time with the light-dark cycle	536	(1)
Hypothalamus and Pituitary	537	(5)
The pituitary gland consists of anterior and posterior lobes	537	(1)
The hypothalamus and posterior pituitary act as a unit to secrete vasopressin and oxytocin	537	(1)
Most anterior pituitary hormones are tropic	538	(2)
Hypothalamic releasing and inhibiting hormones help regulate anterior pituitary hormone secretion	540	(2)
Target gland hormones inhibit hypothalamic and anterior pituitary hormone secretion via negative feedback	542	(1)
Endocrine Control of Growth	542	(5)
Growth depends on growth hormone but is influenced by other factors as well	542	(1)
Growth hormone is essential for growth, but it also exerts metabolic effects not related to growth	543	(1)
Bone grows in thickness and in length by different mechanisms, both stimulated by growth hormone	543	(1)
Growth hormone exerts its growth-promoting effects indirectly by stimulating somatomedins	544	(1)
Growth hormone secretion is regulated by two hypophysiotropic hormones	544	(1)
Abnormal growth-hormone secretion results in aberrant growth patterns	545	(2)
Beyond the Basics: Growth and Youth in a Bottle?	547	(1)
Thyroid Gland	547	(5)
The major cells that secrete thyroid hormone are organized into colloid-filled follicles	547	(1)
Thyroid hormone is synthesized and stored on the thyroglobulin molecule	548	(1)
To secrete thyroid hormone, the follicular cells phagocytize thyroglobulin-laden colloid	549	(1)
Most of the secreted T4 is converted into T3 outside the thyroid	550	(1)
Thyroid hormone is the main determinant of the basal metabolic rate and exerts other effects as well	550	(1)
Thyroid hormone is regulated by the hypothalamus-pituitarythyroid axis	550	(1)
Abnormalities of thyroid function include both hypothyroidism and hyperthyroidism	551	(1)
A goiter develops when the thyroid gland is overstimulated	552	(1)
Adrenal Glands	552	(8)
Each adrenal gland consists of a steroid-secreting cortex and a catecholamine-secreting medulla	552	(1)
The adrenal cortex secretes mineralocorticoids, glucocorticoids, and sex hormones	553	(1)
Mineralocorticoids' major effects are on Na+ and K+ balance and blood pressure homeostasis	553	(1)
Glucocorticoids exert metabolic effects and play a key role in adaptation to stress	554	(1)
Cortisol secretion is regulated by the hypothalamus-pituitary-adrenal cortex axis	555	(1)
The adrenal cortex secretes both male and female sex hormones in both sexes	556	(1)
The adrenal cortex may secrete too much or too little of any of its hormones	557	(1)
The adrenal medulla is a modified sympathetic postganglionic neuron	558	(1)
Epinephrine reinforces the sympathetic nervous system and exerts additional metabolic effects	558	(1)
The stress response is a generalized pattern of reactions to any situation that threatens homeostasis	558	(2)
The multifaceted stress response is coordinated by the hypothalamus	560	(1)
Endocrine Control of Fuel Metabolism	560	(13)
Fuel metabolism includes anabolism, catabolism, and interconversions among energy-rich organic molecules	561	(1)
Because food intake is intermittent, nutrients must be stored for use between meals	562	(1)
The brain must be continuously supplied with glucose	563	(1)
Metabolic fuels are stored during the absorptive state and mobilized during the postabsorptive state	563	(1)
The pancreatic hormones, insulin and glucagon, are most important in regulating fuel metabolism	564	(1)
Insulin lowers blood glucose, fatty acid, and amino acid levels and promotes their storage	565	(1)
The primary stimulus for increased insulin secretion is an increase in blood glucose concentration	566	(1)
The symptoms of diabetes mellitus are characteristic of an exaggerated postabsorptive state	567	(1)
Beyond the Basics: Diabetics and Insulin: Some Have It and Some Don't	568	(2)
Insulin excess causes brain-starving hypoglycemia	570	(1)
Glucagon in general opposes the actions of insulin	571	(1)
Glucagon secretion is increased during the postabsorptive state	571	(1)
Insulin and glucagon work as a team to maintain blood glucose and fatty acid levels	571	(1)
Epinephrine, cortisol, and growth hormone also exert direct metabolic effects	572	(1)
Endocrine Control of Calcium Metabolism	573	(9)
Plasma Ca2+ must be closely regulated to prevent changes in neuromuscular excitability	573	(1)
Parathyroid hormone raises free plasma Ca2+ levels by its effects on bone, kidneys, and intestine	573	(1)
Bone continuously undergoes remodeling	574	(1)
Mechanical stress favors bone deposition	574	(1)
PTH promotes the transfer of Ca2+ from bone to plasma	574	(1)
PTH acts on the kidneys to conserve Ca2+ and eliminate PO3-/4	575	(1)
PTH indirectly promotes absorption of Ca2+ and PO3-/4 by the intestine	575	(1)
The primary regulator of PTH secretion is the plasma concentration of free Ca2+	575	(1)
Calcitonin lowers the plasma Ca2+ concentration but is not important in the normal control of Ca2+ metabolism	575	(1)
Vitamin D is actually a hormone that increases calcium absorption in the intestine	576	(1)
Disorders in Ca2+ metabolism may arise from abnormal levels of PTH or vitamin D	576	(1)
Chapter in Perspective: Focus on Homeostasis	577	(1)
Chapter Summary	577	(3)
Chapter Review Exercises	580	(1)
Points to Ponder	581	(1)
Clinical Consideration	581	(1)
PhysioEdge Resources	581	(1)
The Reproductive System	582
Introduction	583	(5)
The reproductive system includes the gonads, reproductive tract, and accessory sex glands	583	(1)
Reproductive cells each contain a half set of chromosomes	584	(1)
Gametogenesis is accomplished by meiosis	585	(2)
The sex of an individual is determined by the combination of sex chromosomes	587	(1)
Sexual differentiation along male or female lines depends on the presence or absence of masculinizing determinants	587	(1)
Male Reproductive Physiology	588	(8)
The scrotal location of the testes provides a cooler environment essential for spermatogenesis	588	(1)
The testicular Leydig cells secrete masculinizing testosterone	589	(2)
Spermatogenesis yields an abundance of highly specialized, mobile sperm	591	(1)
Throughout their development, sperm remain intimately associated with Sertoli cells	592	(1)
LH and FSH from the anterior pituitary control testosterone secretion and spermatogenesis	593	(1)
Gonadotropin-releasing hormone activity increases at puberty	594	(1)
The reproductive tract stores and concentrates sperm and increases their fertility	594	(1)
The accessory sex glands contribute the bulk of the semen	594	(1)
Prostaglandins are ubiquitous, locally acting chemical messengers	595	(1)
Sexual Intercourse Between Males and Females	596	(5)
The male sex act is characterized by erection and ejaculation	596	(1)
Erection is accomplished by penis vasocongestion	597	(2)
Ejaculation includes emission and expulsion	599	(1)
The female sexual cycle is very similar to the male cycle	599	(1)
Beyond the Basics: Environmental ``Estrogens'': Bad News for the Reproductive System	600	(1)
Female Reproductive Physiology	601
Complex cycling characterizes female reproductive physiology	601	(1)
The steps of gametogenesis are the same in both sexes but the timing and outcome differ sharply	601	(1)
The ovarian cycle consists of alternating follicular and luteal phases	602	(1)
The follicular phase is characterized by the development of maturing follicles	603	(2)
The luteal phase is characterized by the presence of a corpus luteum	605	(1)
The ovarian cycle is regulated by complex hormonal interactions	606	(3)
Cyclic uterine changes are caused by hormonal changes during the ovarian cycle	609	(1)
Pubertal changes in females are similar to those in males	610	(1)
Menopause is unique to females	610	(1)
The oviduct is the site of fertilization	611	(2)
The blastocyst implants in the endometrium through the action of its trophoblastic enzymes	613	(2)
The placenta is the organ of exchange between maternal and fetal blood	615	(1)
Beyond the Basics: The Ways and Means of Contraception	616	(1)
Hormones secreted by the placenta play a critical role in the maintenance of pregnancy	616	(3)
Maternal body systems respond to the increased demands of gestation	619	(1)
Changes during late gestation prepare for parturition	619	(1)
Scientists are closing in on the factors that trigger the onset of parturition	620	(2)
Parturition is accomplished by a positive-feedback cycle	622	(1)
Lactation requires multiple hormonal inputs	623	(2)
Breast-feeding is advantageous to both the infant and the mother	625	(1)
The end is a new beginning	626	(1)
Chapter in Perspective: Focus on Homeostasis	626	(1)
Chapter Summary	626	(2)
Chapter Review Exercises	628	(1)
Points to Ponder	629	(1)
Clinical Consideration	629	(1)
PhysioEdge Resources	629
Appendix A The Metric System	1	(2)
Appendix B A Review of Chemical Principles	3	(16)
Appendix C Storage, Replication, and Expression of Genetic Information	19	(12)
Appendix D The Chemistry of Acid--Base Balance	31	(8)
Appendix E Text References to Exercise Physiology	39	(1)
Appendix F Answers to End-of-Chapter Objective Questions, Points to Ponder, and Clinical Considerations	40
Glossary	1	(1)
Credits	1	(1)
Index	1