PSL-223 Introduction to Physiology - King Khalid University PDF

Human Physiology-PSL-223 Dr. Atiq Hassan College of Applied Medical Sciences King Khalid University  Course Introduction Course title and code: Human Physiology -PSL223. Credit hours: 3 hours (2+1). Program(s) in which the course is offered. Public Health...

Human Physiology-PSL-223 Dr. Atiq Hassan College of Applied Medical Sciences King Khalid University  Course Introduction Course title and code: Human Physiology -PSL223. Credit hours: 3 hours (2+1). Program(s) in which the course is offered. Public Health ands Nursing. Pre-requisites for this course (if any): a. 1st year (Basic Foundation course) b. Biology course in first year II semester  Course Objectives Identify different physiological terminology. Understand the structural organization of human body at chemical, cellular, tissue, organ and system levels. Demonstrate conceptual understanding of the main homeostatic mechanism in the body. Plan, perform and interpret of important physiological functions. Explain the pathophysiological bases of common disease conditions. Course Assessment Date and duration Grades out of 100 Assessment tools Type of questions (day/date/ time) Quiz Any week before 1st MCQs, 5% midterm exam 1st Mid-term Theory 7th week MCQs, 15% Exam 1st Mid-term Theory exam 8th week Spotting, True / Fales, 15% Fill in the blanks 2nd Mid-term Theory 11th week MCQs, 15% Exam Assignment 12th week 10% Final Practical Exam After 15th week Spotting, True / Fales, 15% Fill in the blanks Final Theory Exam After 15th week MCQs, TF, Fill in the 25 % blanks and essay  Learning Resources 1- Ross and Wilson's “Anatomy and Physiology in Health and Illness” 12th Edition; ISBN 978-0-7020-5325-2, International ISBN 978-0-7020-5326-9. 2-Arthur C. Guyton, update, Textbook of Medical Physiology, W.B. Saunders Company. 2010. 3. List Essential References Materials (Journals, Reports, etc.) A- John B. update; Respiratory physiology The William & Wilkins Company Last edition. B- Cecil Gray John Nunn and J.E. Uttering, update; General Anesthesia, Butterwirths Last edition  What Is Physiology? Physiology is the scientific study of the normal functions of living organism. Branches of Physiology Human physiology, cellular physiology, Cardiovascular physiology, Renal Physiology, Respiratory physiology, Gastrointestinal Physiology, Neuro physiology, Muscular Physiology, Endocrine Physiology  Levels of Organization of the Body Levels of organization Chemical. Cellular. Tissue. Organ. System. The human.  Organ System Tissues: group of cells that have similar structure and that function together as a unit. Organs: group of tissue which perform specific or specialized function. Composed of at least two tissue types Perform specific functions Organ System Collection of organs Perform particular task Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Organ Systems Table 1.1 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  ATTENTION! For more details and Preparation for Quizzes and all exams Please read from the reference book Ross and Wilson's Anatomy and Physiology in Health and Illness 12th Edition; ISBN: 13978-0-443-10101-4. (Pages 4-7) Organization of the Body: The Cell Cell: Cell is the smallest structural and functional unit of living organism. Cytology: It is the science that deals with the study of cells as fundamental units of living things. 1. Plasma membrane - forms the cell’s outer boundary - separates the cell’s internal environment from the outside environment - is a selective barrier - plays a role in cellular communication Organization of the Body: The Cell Cell is the smallest structural and functional unit of living organism.  Organization of the Body: The Cell Plasma membrane: Covering membrane present around the cell, it consists of phospholipids, proteins carbohydrates and cholesterol. The phospholipid molecules consist of a head, hydrophilic (meaning ‘water loving’), and a tail hydrophobic (meaning ‘water hating)  Functions of Membrane Proteins Some integral proteins are ion channels Transporters (Carrier Protein)- selectively move substances through the membrane. Receptors - for cellular recognition; a ligand is a molecule that binds with a receptor. Enzymes - catalyze chemical reactions Others act as cell-identity markers Organization of the Body: The Cell 2. Cytoplasm - all the cellular contents between the plasma membrane and the nucleus. - cytosol - the fluid portion, mostly water - organelles - subcellular structures having characteristic shapes and specific functions  Cytoplasm - 2 components 1. Cytosol - intracellular fluid, surrounds the organelles - the site of many chemical reactions - energy is usually released by these reactions - reactions provide the building blocks for cell maintenance, structure, function and growth 2. Organelles: Organelles are small organs’, have individual and highly specialized functions, and are often enclosed in their own membrane within the cytosol. The nucleus, mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes and the cytoskeleton  Organelles - Nucleus Spherical or oval shaped structure Usually most prominent feature of a cell Nuclear envelope - a double membrane that separates the nucleus from the cytoplasm Nuclear pores - numerous openings in the nuclear envelope, control movement of substances between nucleus and cytoplasm Nucleolus - spherical body that produces ribosomes. Chromosomes - contains thousands of hereditary units called genes. Genes - are the cell’s hereditary units, control activities and structure of the cell. Organelles Mitochondria –known as the “powerhouses” of the cell Physiologically active cells have greater number of mitochondria: muscles, liver, kidneys and spermatozoa. It has double membrane, Inner and outer mitochondrial membranes Cristae - the series of folds of the inner membrane Matrix - the large central fluid-filled cavity. It is responsible to generate Energy in form Of ATP by cellular respiration,  Organelles Ribosomes - sites of protein synthesis. These are tiny granules composed of RNA and protein. They synthesize proteins from amino acids, using RNA. Endoplasmic reticulum - network of membranes in the shape of flattened sacs or tubules. - Rough ER - connected to the nuclear envelope, a series of flattened sacs, ribosomes are present on the surface, produces various proteins -Smooth ER - a network of membrane tubules, does not have ribosomes, synthesizes fatty acids and steroids, detoxifies certain drugs Copyright 2009 John Wiley & Sons, Inc. Ribosomes Endoplasmic Reticulum Copyright 2009 John Wiley & Sons, Inc.  Organelles Golgi complex - consists of 3-20 flattened, membranous sacs called cisternae. - Packaging and processing of proteins for transport to different destinations - proteins are transported by various vesicles. -It is present in all cells but is larger in those that synthesize and export proteins. Lysosomes - vesicles that form from the Golgi complex, contain powerful digestive enzymes. -Enzymes involved in breaking down fragments of organelles and large molecules (e.g. RNA, DNA, carbohydrates, proteins) Copyright 2009 John Wiley & Sons, Inc. Golgi Complex Lysosomes Copyright 2009 John Wiley & Sons, Inc. Organelles- cytoskeleton This consists of an extensive network of tiny protein fibers. -provides structural support for the cell Microfilaments. These are the smallest fibers. They provide structural support. It maintain the characteristic shape of the cell e.g. actin in muscle cells. Microtubules. These are larger contractile protein fibers that are involved in movement of: organelles within the cell chromosomes during cell division cell extensions (microvilli, cilia  Organization of the Body: Tissue Tissue: Group of cells that have similar structure and that function together as a unit. Histology: It is the branch of science in which we study structure and functions of the body tissues.  Types of Tissues Four principal types based on function and structure Epithelial tissue covers body surfaces, lines hollow organs, body cavities, and ducts; and forms glands. Connective tissue protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity. Muscle tissue is responsible for movement and generation of force. Nervous tissue initiates and transmits action potentials (nerve impulses) that help coordinate body activities.  Development of Tissues Tissues of the body develop from three primary germ layers: Ectoderm, Endoderm, and Mesoderm Epithelial tissues develop from all three germ layers All connective tissue and most muscle tissues drive from mesoderm Nervous tissue develops from ectoderm  Epithelial Tissues Epithelial tissue consists of cells arranged in continuous sheets, in either single or multiple layers Closely packed and held tightly together Covering and lining of the body Free surface 3 major functions: Protection of underlying structures from, for example, dehydration, chemical and mechanical damage Secretion Absorption.  General Features of Epithelial Cells Surfaces of epithelial cells differ in structure and have specialized functions Apical (free) surface Faces the body surface, body cavity, lumen, or duct Lateral surfaces Faces adjacent cells Basal surface Opposite of apical layer and adhere to extracellular materials  Covering and Lining Epithelium Arrangement of cells in layers Consist of one or more layers depending on function Simple epithelium Single layer of cells that function in diffusion, osmosis, filtration, secretion, or absorption Pseudostratified epithelium Appear to have multiple layers because cell nuclei at different levels All cells do not reach the apical surface Stratified epithelium Two or more layers of cells that protect underlying tissues in areas of wear and tear Simple epithelium. Simple epithelium Squamous (pavement) epithelium This is composed of a single layer of flattened cells Thin cells, arranged like floor tiles Allows for rapid passage of substances. It forms the lining of the following structures: heart – where it is known as endocardium blood vessels where it is also known lymph vessels as endothelium Alveoli of the lungs Lining the collecting ducts of nephrons in the kidneys Copyright 2009, John Wiley & Sons, Inc. Simple epithelium Cuboidal This consists of cube-shaped cells. It forms the kidney tubules and is found in some glands such as the thyroid. Cuboidal epithelium is actively involved in secretion, absorption and/or excretion. Columnar This is formed by a single layer of cells, rectangular in shape, May have cilia (in Trachea) or microvilli (in small Intestine) Specialized function for secretion e.g. goblet cells that secrete mucus.  Stratified Epithelium Two or more layers of cells Specific kind of stratified epithelium depends on the shape of cells in the apical layer. Stratified squamous epithelium Stratified cuboidal epithelium Stratified columunar epithelium Transitional epithelium Stratified Squamous Epithelium Several layers of cells that are flat in the apical layer New cells are pushed up toward apical layer As cells move further from the blood supply they dehydrate, harden, and die Keratinized form contain the fibrous protein keratin Found in superficial layers of the skin Nonkeratinized form does not contain keratin Found in mouth and esophagus Copyright 2009, John Wiley & Sons, Inc.  Transitional Epithelium Found only in the urinary system Variable appearance In relaxed state, cells appear cuboidal Upon stretching, cells become flattened and appear squamous Ideal for hollow structure subjected to expansion Copyright 2009, John Wiley & Sons, Inc.  Glandular Epithelium: Glands Formed from epithelium Manufacture a product Major classes of glands Exocrine glands Have ducts Endocrine glands No ducts, product into blood Product = hormone Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Epithelium: Exocrine Glands Secrete products into ducts that empty onto the surfaces of epithelium Skin surface or lumen of a hollow organ Secretions of the exocrine gland include mucus, sweat, oil, earwax, saliva, and digestive enzymes Examples of glands include sudoriferous (sweat) glands Epithelium: Endocrine Glands Secretions, called hormones, diffuse directly into the bloodstream Function in maintaining homeostasis Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Muscular Tissue Consists of elongated cells called muscle fibers or myocytes. Cells use ATP to generate force Several functions of muscle tissue Classified into 3 types: skeletal, cardiac, and smooth muscular tissue  Skeletal Muscle Tissue Attached to bones of the skeleton Have striations Voluntary movement or contractions by conscious control Vary in length (up to 40 cm) and are roughly cylindrical in shape Copyright 2009, John Wiley & Sons, Inc. Muscular Tissue Cardiac muscle tissue Have striations Involuntary movement or contraction is not consciously controlled Intercalated disc unique to cardiac muscle tissue Copyright 2009, John Wiley & Sons, Inc.  Smooth Muscle Tissue Walls of hollow internal structures Blood vessels, airways of lungs, stomach, and intestines Nonstriated Usually involuntary control  Nervous Tissue Two types of tissue are found in the nervous system: Excitable cells – these are called neurons or nerve cell and they initiate, receive, conduct and transmit information. Non-excitable cells – also known as glial cells, these support the neurons. Astrocytes Ependymal cell Schwann cell Oligodendrocytes Microglia Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Excitable Cells Neurons and muscle fibers Exhibit electrical excitability The ability to respond to certain stimuli by producing electrical signals such as action potentials Actions potentials propagate along a nerve or muscle plasma membrane to cause a response Release of neurotransmitters Muscle contraction Copyright 2009, John Wiley & Sons, Inc. Neurons and Nerve Tissue  Connective Tissue Most diverse of the four tissues Characterized by extracellular matrix Anchors and links structures of body Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Connective Tissue Examples of connective tissue Bone Tendons Fat Blood Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Connective Tissue Figure 1.2d Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  ATTENTION! For more details and Preparation for Quizzes and all exams Please read from the reference book Ross and Wilson's Anatomy and Physiology in Health and Illness 12th Edition; ISBN: 13978-0-443-10101-4. (Pages 32-45)  Body Fluid Compartments Internal environment = fluid surrounding cells = extracellular fluid (ECF) 70 kg man - Total body water = 42 liters 28 liters intracellular fluid (ICF) 14 liters extracellular fluid (ECF) - Three liters plasma - 11 liters interstitial fluid (ISF) Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. A Simplified Body Plan Figure 1.4 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Body Fluids and Compartments Figure 1.5a–c Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Body Fluids and Compartments Figure 1.5c–e Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis Ability to maintain a relatively constant internal environment Conditions of the internal environment which are regulated include Temperature Volume Composition Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Terms Negative feedback If a regulated variable decreases, System responds to make it increase, and vice versa Tends to be self correcting Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Terms Set point Expected value of regulated variable Examples Core body temperature = 37º C Blood glucose (sugar) = 100 mg/dL Blood pH = 7.4 Error signal Difference between value of set point and regulated variable Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Homeostasis: Terms Figure 1.6c–d Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Components Structures enabling homeostasis Components include Receptors Integrating Centers Effectors Signals Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Components Receptors Sensors which detect stimuli Receptors include Thermoreceptors Chemoreceptors Baroreceptors Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Components Integrating center Orchestrates an appropriate response Often particular sets of neural circuits in brain Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Components Effectors Responsible for body responses Effectors include Muscles (smooth, striated, and cardiac) Glands Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Components Signals Allow components to communicate Input signal is from a receptor to an integrating center Output signal is from an integrating center to an effector Signals are chemical or via neurons Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Negative Feedback Loop Figure 1.7 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Positive Feedback Loop Positive feedback loops cause a rapid change in a variable. Figure 1.8 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Thermoregulation Core body temperature Humans: 37º C (98.6º F) Hypothermia = decrease in body temperature Hyperthermia = increase in body temperature Above 41º C is dangerous Above 43º C is deadly Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Homeostasis: Thermoregulation Mechanisms of heat transfer between body and external environment Radiation—thermal energy as electromagnetic waves Conduction—thermal energy through contact Evaporation—heat loss through evaporation of water Insensible water loss Sweating Convection—heat transfer by movement of fluid or air Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Thermoregulation: Components Receptors = thermoreceptors Central: found in CNS (hypothalamus) Peripheral: found in PNS (mainly skin) Effectors Glands: sweat glands Muscles: skeletal muscles, and smooth muscle of cutaneous blood vessels Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Thermoregulation: Components Integrating center Thermoregulatory center in hypothalamus Signals Nerve impulses via neurons Chemicals via hormones Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Thermoneutral Zone Range of outside temperature where alterations in blood flow alone regulates body temperature—25-30ºC Body temperature increase Blood flow to skin increases Body temperature decrease Blood flow to skin decreases Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Thermoregulation Negative feedback control of body temperature Figure 1.9a, b Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings. Thermoregulation Figure 1.9c Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.  Fever Rise in core body temperature Accompanies infection White blood cells secrete pyrogens Body temperature set point increases Fever enhances immune response Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.