1625915643-5d53d156c9525bd62bd0d3434ecdc231 (Netters - Essential Physiology (на английском)), страница 2

Now translated into 16 languages, it is theanatomy atlas of choice among medical and health professions students the worldover.The Netter illustrations are appreciated not only for their aesthetic qualitiesbut, more importantly, for their intellectual content. As Dr. Netter wrote in 1949,“. . . clarification of a subject is the aim and goal of illustration. No matter howbeautifully painted, how delicately and subtly rendered a subject may be, it is of littlevalue as a medical illustration if it does not serve to make clear some medical point.”Dr.

Netter’s planning, conception, point of view, and approach are what informs hispaintings and what makes them so intellectually valuable.Frank H. Netter, MD, physician and artist, died in 1991.Learn more about the physician-artist whose work has inspired the Netter Reference collection: http://www.netterimages.com/artist/netter.htm.CARLOS A.G.

MACHADO, MD, was chosen by Novartis to be Dr. Netter’ssuccessor. He continues to be the main artist who contributes to the Netter collectionof medical illustrations.Self-taught in medical illustration, cardiologist Carlos Machado has contributedmeticulous updates to some of Dr.

Netter’s original plates and has created manypaintings of his own in the style of Netter as an extension of the Netter collection.Dr. Machado’s photorealistic expertise and his keen insight into the physician/patientrelationship informs his vivid and unforgettable visual style. His dedication toresearching each topic and subject he paints places him among the premier medicalillustrators at work today.Learn more about his background and see more of his art at http://www.netterimages.com/artist/machado.htm.xiiiThis page intentionally left blankCONTENTSSection 1: Cell Physiology, Fluid Homeostasis,and Membrane Transport1.

The Cell and Fluid Homeostasis . . . . . . . . . . . . . . . . .2. Membrane Transport . . . . . . . . . . . . . . . . . . . . . . . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31321Section 2: The Nervous System and Muscle3. Nerve and Muscle Physiology . . . . . . . . . . . . . . . .

. . .4. Organization and General Functions of theNervous System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. Sensory Physiology . . . . . . . . . . . . . . . . . . . . . . . . . . .6. The Somatic Motor System . . . . . . . . . . . . . . . . . . . .7. The Autonomic Nervous System . . . . . . . . . . .

. . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .254959778793Section 3: Cardiovascular Physiology8. Overview of the Heart and Circulation . . . . . . . . . . . .9. Cardiac Electrophysiology . . . . . . . . . . .

. . . . . . . . . .10. Flow, Pressure, and Resistance . . . . . . . . . . . . . . . . .11. The Cardiac Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . .12. The Peripheral Circulation . . . . . . . . . . . . . . . . . . . . .Review Questions . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .97101107113125142Section 4: Respiratory Physiology13. Pulmonary Ventilation and Perfusion andDiffusion of Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . .14. The Mechanics of Breathing . . . . . .

. . . . . . . . . . . . . .15. Oxygen and Carbon Dioxide Transport andControl of Respiration . . . . . . . . . . . . . . . . . . . . . . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147163179192xvxviContentsSection 5: Renal Physiology16. Overview, Glomerular Filtration,and Renal Clearance . . . . .

. . . . . . . . . . . . . . . . . . . . .17. Renal Transport Processes . . . . . . . . . . . . . . . . . . . . .18. Urine Concentration and Dilution Mechanisms . . . . .19. Regulation of Extracellular Fluid Volumeand Osmolarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20. Regulation of Acid–Base Balanceby the Kidneys . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197209219225231239Section 6: Gastrointestinal Physiology21. Overview of the Gastrointestinal Tract . . . . . . . . . . . .22. Motility through the Gastrointestinal Tract . . . . . . . .23. Gastrointestinal Secretions . . . . . . . .

. . . . . . . . . . . . .24. Hepatobiliary Function . . . . . . . . . . . . . . . . . . . . . . . .25. Digestion and Absorption . . . . . . . . . . . . . . . . . . . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243253271283291301Section 7: Endocrine Physiology26. General Principles of Endocrinology andPituitary and Hypothalamic Hormones . . . . . . . .

. . . .27. Thyroid Hormones . . . . . . . . . . . . . . . . . . . . . . . . . . . .28. Adrenal Hormones . . . . . . . . . . . . . . . . . . . . . . . . . . . .29. The Endocrine Pancreas . . . . . . . . . . . . . . . . . . . . . . .30. Calcium-Regulating Hormones . . . . . . . . . .

. . . . . . . .31. Hormones of the Reproductive System . . . . . . . . . . .Review Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .307321329339347355367Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .371Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .377Section1CELL PHYSIOLOGY, FLUIDHOMEOSTASIS, ANDMEMBRANE TRANSPORTPhysiology is the study of how the systems of the body work, not only on anindividual basis, but also in concert to support the entire organism. Medicineis the application of physiologic principles, and understanding these principlesgives us insight into the development of disease. The terms regulation andintegration will keep surfacing as you learn more about how each systemfunctions.

Because of these building interactions, the field of physiology isalways expanding. As we discover more about the genes, molecules, andproteins that regulate other factors, we see that the discipline of physiologyis far from static. Each new discovery gives us more insight into how ourimpossibly complex organism exists, and how we might intercede whenpathophysiology occurs. This text will explore essential elements in each of thebody’s systems; it is not intended to be comprehensive, but focuses, rather, onensuring a solid understanding of these principles related to the regulation andintegration of the systems.Chapter 1The Cell and Fluid HomeostasisChapter 2Membrane TransportReview Questions1This page intentionally left blank3Chapter1The Cell and Fluid HomeostasisCELL STRUCTURE AND ORGANIZATIONOrganisms evolved from single cells floating in the primordialsea (Fig.

1.1). A key to appreciating how multicellular organisms exist is through understanding how the single cellsmaintained their internal fluid environment when exposeddirectly to the outside environment with the only barrierbeing a semipermeable membrane. Nutrients from the “sea”entered the cell, diffusing down their concentration gradientsthrough channels or pores, and waste was transported outthrough exocytosis.

In this simple system, if the external environment changed (e.g., if salinity increased due to excess heatand evaporation of sea water or water temperature changed),the cell adapted or perished. To evolve to multicellular organisms, cells developed additional barriers to the outside environment to allow better regulation of the intracellularenvironment.In multicellular organisms, cells undergo differentiation,developing discrete intracellular proteins, metabolic systems,and products. The cells with similar properties aggregate andbecome tissues and organ systems [cells → tissues → organs→ systems].Various tissues serve to support and produce movement(muscle tissue), initiate and conduct electrical impulses(nervous tissue), secrete and absorb substances (epithelialtissue), and join other cells together (connective tissue).

Thesetissues combine and support organ systems that control othercells (nervous and endocrine systems), provide nutrient inputand continual excretion of waste (respiratory and gastrointestinal systems), circulate the nutrients (cardiovascular system),filter and monitor fluid and electrolyte needs and rid the bodyof waste (renal system), provide structural support (skeletalsystem), and provide a barrier to protect the whole structure(integumentary system [skin]) (Fig. 1.2).THE CELL MEMBRANEThe human body is composed of eukaryotic cells (those thathave a true nucleus) containing various organelles (mitochondria, smooth and rough endoplasmic reticulum, Golgiapparatus, etc.) that perform specific functions.

The nucleusand organelles are surrounded by a plasma membrane con-sisting of a lipid bilayer primarily made of phospholipids, withvarying amounts of glycolipids, cholesterol, and proteins. Thelipid bilayer is positioned with the hydrophobic fatty acid tailsof phospholipids oriented toward the middle of the membrane, and the hydrophilic polar head groups oriented towardthe extracellular or intracellular space. The fluidity of themembrane is maintained in large part by the amount of shortchain and unsaturated fatty acids incorporated within thephospholipids; incorporation of cholesterol into the lipidbilayer reduces fluidity (Fig. 1.3).

The oily, hydrophobic interior region makes the bilayer an effective barrier to fluid (oneither side), with permeability only to some small hydrophobic solutes, such as ethanol, that can diffuse through thelipids.To accommodate multiple cellular functions, the membranesare actually semipermeable because of a variety of proteinsinserted in the lipid bilayer. These proteins are in the form ofion channels, ligand receptors, adhesion molecules, and cellrecognition markers. Transport across the membrane caninvolve passive or active mechanisms and is dictated by themembrane composition, concentration gradient of the solute,and availability of transport proteins (see Chapter 2).

If theintegrity of the membrane is disrupted by changing fluidity,protein concentration, or thickness, transport processes willbe impaired.FLUID COMPARTMENTS: SIZE ANDCONSTITUTIVE ELEMENTSFluid Compartments and SizeThe typical adult body is approximately 60% water; in a 70kilogram (kg) person, this equals 42 liters (L) (Fig. 1.4). Theactual size of all fluid compartments is dependent on a varietyof factors including size and body mass index. In the normal70-kg adult:■■Intracellular fluid (ICF) constitutes 2/3 of the total bodywater (28 L), and the extracellular fluid (ECF) accountsfor the other 1/3 of total body water (14 L).The extracellular fluid compartment is composed of theplasma (blood without red blood cells) and the interstitial4Cell Physiology, Fluid Homeostasis, and Membrane TransportReception and processingof signalsIngestionCO2Gasexchange⫹IonexchangeO2⫺⫹H2OGeneticmaterialDigestionWaterbalanceMotilityExcretionHeatexchangeFigure 1.1 Cell in the Primordial Sea The first single-celled organisms had to perform basic functions and be able to adapt to changes in their immediate external environment.

The semipermeable cellmembrane facilitated the processes that provided nutrients to the cell, using diffusion, endocytosis andexocytosis, and protein transporters to maintain homeostasis.fluid (ISF), which is the fluid bathing cells (outside ofthe vascular system) as well as the fluid in bone andconnective tissue. Plasma constitutes 1/4 of ECF (3.5 L),and ISF constitutes the other 3/4 of ECF (10.5 L).The amount of total body water (TBW) differs with age andgeneral body type. TBW in rapidly growing infants is ~75%of body weight, whereas older adults have a lower percentage.In addition, body fat plays a role: obese individuals havelower TBW than age-matched individuals, and, in general,women have less TBW than age-matched men.