Chapter 1 - Study of Body Function PDF

9/8/24 Human Physiology Chapter 1...

9/8/24 Human Physiology Chapter 1 BIOL 307 / KINS 307 The Study of Body Function Lecture Outline Chapter 1: u Human Physiology The Study of Body Function Sixteenth Edition u Stuart Ira Fox u Krista Rompolski 6 & 9 September, 2024 u Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC. 1 2 Objectives u Describe the scientific study of human physiology. u Describe the characteristics of the scientific method. u Define homeostasis and identify the components of negative feedback loops. u Explain the role of antagonistic effectors in maintaining homeostasis, and the nature of positive feedback loops. I. Introduction to u Give examples of how negative feedback loops involving the nervous and endocrine systems help to maintain homeostasis. Physiology u Distinguish the primary tissues and their subtypes. u Relate the structure of the primary tissues to their functions. u Use the skin as an example to describe how the different primary tissues compose organs. u Identify the body fluid compartments. 4 3 4 1  9/8/24 A. What is Physiology? A. What is Physiology? 1. Study of biological function; 2. Pathophysiology how the body works a. Concerns how disease or a. Concerned with the injury affects physiological normal function of cells to processes the organism as a whole b. Aids understanding of b. Emphasizes mechanisms normal processes – how it works c. Explains using cause and effect sequences d. Derived from scientific experiments 5 6 A. What is Physiology? B. The Scientific Method 3. Comparative physiology Steps a. Studies the differences 1. Make observations. and similarities in the 2. Form a hypothesis; the hypothesis functions of invertebrates must be testable. and vertebrates 3. Design and conduct experiments or b. Has aided in the development of make more observations. pharmaceutical drugs 4. Analyze the data. 5. Results must be replicated many times before a conclusion is accepted. 6. Several verified hypotheses may become a general theory based on reproducible data. https://www.frontiersin.org/journals/veterinary- science/articles/10.3389/fvets.2020.00552/full 7 8 2  9/8/24 B. The Scientific Method B. The Scientific Method 3. Developing Pharmaceuticals 2. Measurements, Controls, and a. Basic research is conducted for years before a drug is ever Statistics given to a person. a. Good physiological research b. Research begins by studying the effects of a chemical on requires: cells in vitro (in a culture dish). 1) Quantifiable measurements c. Next, studies are done in animals (usually rats and mice) to 2) An experimental group and a see if the same effects occur in vivo (in a living creature) and control group if there are any toxic side effects. 3) Reduction of bias 4) Statistical analysis 5) Review and publication by a peer-reviewed journal 1 0 9 10 B. The Scientific Method B. The Scientific Method 3. Developing Pharmaceuticals, Continued 3. Developing Pharmaceuticals, Continued 1) For these trials, many rats and mice are genetically d. Phases of Clinical Trials modified to be susceptible to particular diseases. 1) Phase I clinical trials test the drug on healthy human 2) Animal trials may take several years. volunteers - side effects, rates of passage, dosage, etc. 1 2 11 12 3  9/8/24 B. The Scientific Method 2) Phase II - people with the particular disease. 3) Phase III - large number of people (sexes, age groups, ethnicities, other health condition). 4) FDA can approve the drug for sale. 5) Phase IV trials - other applications. 1 3 13 14 Why is this important? 1. What was the research u Willowbrook Hepatitis Experiments question or hypothesis? u Tuskegee Syphilis Study u 1962: Dr. Chester Southam II. Homeostasis and 2.u As NaziaHuman research ethics Experiments u board, Indigenous highlight Populations In the Canada Feedback Control biggest (1933 TB) ethical issue in this study… 1 6 15 16 4  9/8/24 A. Brief History of Physiology B. Homeostasis 1. Walter Cannon – U.S. (1932) – coined the term homeostasis to describe the internal consistency of the body – Fight or flight response 1. Homeostasis is constancy of the internal environment. 2. The main purpose of our physiological mechanisms is to maintain homeostasis. 3. Deviation from homeostasis indicates disease. 4. Homeostasis is accomplished most often by negative feedback loops. 1 9 17 19 C. Feedback Loops C. Feedback Loops 1. Pathway a. Receptors - detect change & send information b. Integrating center, assesses & sends instructions c. Effector (muscles or glands), make adjustments; counter the change from the set-point 20 21 5  9/8/24 C. Negative Feedback Loops C. Negative Feedback Loops 2. Mechanism of Negative Feedback Loops a. Moves in the opposite direction from the change b. Reverses the change in the set-point c. This is a continuous process 22 23 C. Negative Feedback Loops D. Positive Feedback 4. Antagonistic Effectors 1. The end product stimulates the a. Opposing effectors - move conditions in opposite directions. process. 1) Within a certain normal range, or dynamic constancy. 2. The action amplifies the changes b. When you are hot, you sweat; when you are cold, you that stimulated the effectors shiver. These are antagonistic reactions. 3. Positive feedback - contributes to many negative feedback loops. a. For example, if a blood vessel is damaged - form a clot (+ feedback) - clotting ends c. Other examples – blood glucose levels, blood calcium (- feedback). levels, heart rate, and blood pH b. Uterine contractions during childbirth - positive feedback loop. 25 30 6  9/8/24 F. Feedback Control of Hormone Secretions III. The Primary Tissues 3 5 34 35 A. Levels of Organization B. Systems 1. Cell – basic unit u TABLE 1.4 Organ Systems of the Body 2. Tissue – group of similar cells System Major Organs Primary Functions -> similar function Integumentary Skin, hair, nails Protection, thermoregulation Nervous Brain, spinal cord, nerves Regulation of other body systems 3. Organ – group of two or more Endocrine Hormone-secreting glands, such as the Secretion of regulatory molecules called tissues pituitary, thyroid, and adrenal glands hormones Skeletal Bones, cartilages Movement and support 4. System – group of organs that work together Muscular Skeletal muscles Movements of the skeleton Circulatory Heart, blood vessels, lymphatic Movement of blood and lymph 5. Organism – systems working vessels in coordination Immune Red bone marrow, lymphoid organs Defense of the body against invading pathogens Respiratory Lungs, airways Gas exchange Urinary Kidneys, ureters, urethra Regulation of blood volume and composition Alimentary Mouth, stomach, intestine, liver, Breakdown of food into molecules that gallbladder, pancreas enter the body Reproductive Gonads, external genitalia, associated Continuation of the human species glands and ducts 3 7 36 37 7  9/8/24 B. The Primary Tissues C. Muscle Tissue 1. Our organs are composed of four major categories of tissues: u Specialized for contraction a. Muscle tissue u The three types are: b. Nervous tissue a. Skeletal muscle c. Epithelial tissue b. Cardiac muscle c. Smooth muscle d. Connective tissue 38 39 C. Muscle Tissue C. Muscle Tissue 2. Cardiac Muscle Tissue 1. Skeletal Muscle Tissue a. Found only in the heart a. Voluntary muscle b. Fibers are short, branched, and interconnected both physically (consciously controlled) and electrically b. Most associated with c. Striated, but very different in structure and action from skeletal bones -> movements muscle. c. Has visible striations d. Involuntary from sarcomeres e. Can not produce a graded contraction d. ability to vary the grade or strength of contraction e. Fibers arranged parallel 4 3 40 43 8  9/8/24 C. Muscle Tissue D. Nerve Tissue 3. Smooth Muscle Tissue 1. Found in the brain, spinal cord, and nerves a. Found in the walls of digestive, urinary, and reproductive organs, 2. Composed of neurons and neuroglia blood vessels, and bronchioles of the lungs (hollow organs) 3. Neurons conduct impulses and have three parts: b. Not striated, a. Dendrites: short, highly branched, cytoplasmic extensions that receive signals c. Involuntary b. Axon: long, single extension that sends signal d. Tapered shape c. Cell body: metabolic center containing the nucleus 4. Neuroglia are supporting cells that do not conduct a nerve impulse but are essential for neuron function 4 6 46 48 E. Epithelial Tissue E. Epithelial Tissue 1. Forms the membranes that cover body surfaces and line the inside of 3. Epithelial tissues are also classified by the shape of their cells: hollow organs, and glands a. Squamous: flattened cells b. Cuboidal: as tall as they are long 2. Epithelial membranes are classified by the number of layers: c. Columnar: tall cells a. Simple epithelium -> one layer -> transport of substances. 4. Put the cell shape together with the number of layers to name b. Stratified epithelium -> multiple layers -> provides protection. epithelial tissue 5. Some modifications can occur such as cilia that move in a coordinated fashion. 5 0 50 51 9  9/8/24 E. Epithelial Tissue E. Epithelial Tissue 8. Exocrine Glands u TABLE 1.3 Summary of Epithelial Membranes a. Derived from epithelial tissues Type Structure and Function Location Covering visceral organs; linings of body cavities, b. Secretions are transported by ducts. Sim ple Epithelia Single layer of cells; function varies w ith type tubes, and ducts Sim ple squam ous Single layer of flattened, tightly bound cells; diffusion Capillary w alls; pulm onary alveoli of lungs; covering 1) Examples include lacrimal, sweat, and sebaceous glands; epithelium and filtration visceral organs; linings of body cavities digestive enzyme glands; and the prostate. Sim ple cuboidal Single layer of cube-shaped cells; excretion, Surface of ovaries; linings of kidney tubules, salivary epithelium secretion, or absorption ducts, and pancreatic ducts Sim ple colum nar Single layer of nonciliated, tall, colum n-shaped cells; 9. Endocrine glands Lining of m ost of digestive tract epithelium protection, secretion, and absorption Sim ple ciliated colum nar Single layer of ciliated, colum n-shaped cells; a. Lack ducts -> secrete into capillaries. Lining of uterine tubes epithelium transportive role through ciliary m otion b. Endocrine glands will be described in chapter 11. Pseudostratified ciliated Single layer of ciliated, irregularly shaped cells; m any colum nar epithelium goblet cells; protection, secretion, ciliary m ovem ent Lining of respiratory passagew ays 1) Examples include many hormone producing glands such Stratified Epithelia Tw o or m ore layers of cells; function varies w ith type Epiderm is of skin; linings of body openings, ducts, as the thyroid gland, adrenal glands, etc. and urinary bladder Stratified squam ous Num erous layers containing keratin, w ith outer layers Epiderm is of skin epithelium (keratinized) flattened and dead; protection Stratified squam ous Num erous layers lacking keratin, w ith outer layers Linings of oral and nasal cavities, vagina, and anal epithelium m oistened and alive; protection and pliability canal (nonkeratinized) Stratified cuboidal Usually tw o layers of cube-shaped cells; strengthening Large ducts of sw eat glands, salivary glands, and epithelium of lum inal w alls pancreas Num erous layers of rounded, nonkeratinized cells; Transitional epithelium W alls of ureters, part of urethra, and urinary bladder distension 52 60 F. Connective Tissue F. Connective Tissue 3. Connective Tissue Proper 1. Characterized by a matrix made up a. Composed of protein fibers and a gel-like ground substance of protein fibers, extracellular b. Subtypes: material, and specialized cells 1) Loose: collagen fibers scattered loosely with room for blood vessels and nerves 2. There are four major categories: Example: dermis of the skin a. Connective tissue proper 2) Dense regular: Densely packed collagen fibers with little room for ground substance b. Cartilage Examples: tendons and ligaments c. Bone d. Blood 62 63 10  9/8/24 Connective Tissue Proper Cartilage b. Subtypes, Continued 4. Cartilage Connective Tissue 3) Adipose tissue stores fat; cells called adipocytes a. Composed of cells called chondrocytes surrounded by a semi-solid ground substance 4) Dense irregular densely b. Serves as a template skeleton during bone development packed collagen fibers in c. Found in joints to provide a gliding surface for bones various arrangements to resist forces. 65 66 Bone C. Body Fluid Compartments 5. Bone 1. Intracellular: area inside the cells; a. Cells called osteoblasts trap mineral salts -> forming contains 65% of total body water concentric layers of calcified material = lamellae 2. Extracellular: area outside the cells; b. Once the matrix has hardened -> osteocytes and live in spaces examples: called lacunae. a. blood plasma and b. interstitial fluid 3. Both body fluid compartments are filled primarily with water 4. Separated by membranes. 6 7 7 6 67 76 11