Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 1 The Study of Body Function 1-1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 1 Outline  Introduction to Physiology  Scientific Method  Homeostasis  Muscle Tissue  Nervous Tissue  Epithelial Tissue  Connective Tissue  Organs & Systems 1-2

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Physiology  Physiology: study of how body works to maintain life  Pathophysiology: how physiological processes are altered in disease or injury 1-3

Scientific Method 1-4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Scientific Method  1. Form a testable hypothesis about observations  2. Conduct & analyze experiments to test hypothesis  3. Draw conclusions about whether or not results support hypothesis  4. Develop a theory  = general statement explaining natural phenomena that is based on proven hypotheses 1-5

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Testing of Hypotheses  Involves:  Experimental & control groups  Quantitative measurements performed blindly  Analysis of data using statistics 1-6

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Using Scientific Method to Develop New Drugs  When a new drug is suggested by experiments:  Its effectiveness & toxicity tested first in tissue culture, rats, mice 1-7

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Using Scientific Method to Develop New Drugs  If effective & safe, clinical trials performed  Phase I Trials: Toxicity & metabolism tested in healthy human volunteers  Phase II Trials: Effectiveness & toxicity tested in target population  Phase III Trials: Widespread test of drug in diverse population  Phase IV Trials: Drug is tested for other uses 1-8

Homeostasis 1-9

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis  Is maintenance of fairly constant internal conditions  Around physiological set points  Maintained by negative feedback loops Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback Loops  Sensor: Detects deviation from set point  Integrating center: Determines response  Effector: Produces response Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Homeostasis  Regulatory mechanisms:  Intrinsic control is built into organ being regulated  Extrinsic control comes from outside of organ  By nervous or endocrine systems  E.g. nervous control of body temperature Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Negative Feedback Hormonal Control of Blood Glucose Fig

Muscle Tissue 1-14

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Primary Tissues  Primary tissues include muscle, nervous, epithelial, connective 1-15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Muscle Tissue  Specialized for contraction  3 types: skeletal, cardiac, smooth 1-16

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skeletal Muscle  Is striated; voluntary  Each fiber forms by fusion of embryonic myoblasts  To become large & multinucleated  Individually controlled  Lined-up in parallel to form bundles 1-17 Fig 1.7

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cardiac Muscle  Is striated; involuntary  Branched to form continuous fabric  Intercalated discs between cells provide mechanical & electrical interconnections  Fibers not individually controlled 1-18 Fig 1.8

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Smooth Muscle  Is not striated; involuntary  Found in many organs, tissues  Controlled by ANS 1-19 Fig 1.9

Nervous Tissue 1-20

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous Tissue  Consists of neurons & supporting or glial cells  Neurons are specialized for conducting electrical signals  Have cell body, dendrites & axon (Fig 1.10) 1-21

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous Tissue  Cell body contains nucleus; is metabolic center  Dendrites: highly branched extensions off cell body  Receive inputs from other neurons  Axon: single, long extension off cell body  Conducts nerve impulses to other cells  Supporting/Glial cells provide physical & functional support for neurons  5X more abundant than neurons 1-22

Epithelial Tissue 1-23

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue  Lines & covers body surfaces  Consists of cells that form membranes & glands  Regularly replaced  Squamous epithelial cells are flattened  Columnar epithelial cells are taller than wide  Cuboidal epithelial cells are cube-shaped 1-24

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue  Simple membranes are one cell thick  Specialized for transport  Stratified has a number of layers  Specialized for protection 1-26

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue  Non-keratinized stratified squamous consists of living cells (Fig 1.12)  Keratinized stratified squamous has outer layer of dead cells  Cells contain water-resistant keratin Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epithelial Tissue  Cells are joined by junctional complexes which increase strength & create barrier  Separated from underlying tissue by basement membrane Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Exocrine Glands  Derived from epithelial cells  Secrete onto epithelium via ducts  Can be simple tubes or clusters called acini Fig

Connective Tissue 1-30

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue  Has lots of extracellular material deposited in space between its cells  Includes connective tissue proper, cartilage, bone & blood  Loose connective tissue consists of collagen (fibrous proteins) & tissue fluid  E.g. dermis of skin 1-31

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue Proper Fig 1.17  Dense fibrous connective tissue is packed with fibers of collagen  Can be regularly arranged as in tendons  Or irregularly oriented as in capsules, sheaths (Fig 1.16) 1-32

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue - Adipose  Specialized for fat synthesis, breakdown & storage Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue - Cartilage  Specialized for support, protection  Made of chondrocytes & elastic extracellular material  Serves as precursor for bone  Forms articular surfaces for joints 1-34

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Connective Tissue - Bone  Formed as concentric layers of calcified material  Contains 3 cell types:  Osteoblasts: bone- forming cells  Osteocytes: trapped, inactive osteoblasts  Osteoclasts: the bone resorbing cells Fig

Organs & Systems 1-36

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Organs  Are anatomical & functional units made of 2 or more primary tissues  Systems are groups of organs working together to maintain homeostasis 1-37

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Skin--The Largest Organ  Has a outer layer of protective cornified epidermis  Next layer is dermis which contains connective tissue, glands, blood vessels, nerves  Inner layer is hypodermis which contains fat Fig

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Body-Fluid Compartments  Body has intracellular & extracellular compartments  Intracellular is inside cells  Extracellular is outside cells  Separated by cell’s outer membrane  Extracellular is composed of blood plasma & interstitial fluid 1-39