UNIT 1 2024-2025- INTRODUCTION TO ANATOMY AND PHYSIOLOGY.pdf

UNIT 1 – THE BASICS Sarah Tan de Luna, MD, MPH OUTLINE ◼ TOPIC 1 – Introduction to Anatomy and Physiology ◼ TOPIC 2 – The Living Being ◼ TOPIC 3 - Homeostasis TOPIC 1 – INTRODUCTION TO ANATOMY AND PHYSIOLOGY INTRODUCTION ◼ Anatomy and physiology (A&P) is about human structure and function—the...

UNIT 1 – THE BASICS Sarah Tan de Luna, MD, MPH OUTLINE ◼ TOPIC 1 – Introduction to Anatomy and Physiology ◼ TOPIC 2 – The Living Being ◼ TOPIC 3 - Homeostasis TOPIC 1 – INTRODUCTION TO ANATOMY AND PHYSIOLOGY INTRODUCTION ◼ Anatomy and physiology (A&P) is about human structure and function—the biology of the human body ◼ We want to know how our body works! INTRODUCTION ◼ A&P is a foundation for advanced study in health care, pathophysiology, and other health-care-related fields ◼ Anatomy and Physiology are always related. Structure determines what functions can take place. STRUCTURE DETERMINES FUNCTION – MOLECULAR LEVEL- Shape Determines Function ◼ Collagen, a fibrous ◼ Hemoglobin – a protein found in the globular or round skin protein STRUCTURE DETERMINES FUNCTION – MOLECULAR LEVEL ◼ Fibrous proteins, such as collagen, are shaped like a rope and give strength to our skin to prevent it from tearing. ◼ Fibrous proteins are structural proteins because they help give shape to and support the skin. STRUCTURE DETERMINES FUNCTION – MOLECULAR LEVEL ◼ Globular proteins, such as hemoglobin, are used to transport oxygen in the blood. ◼ Enzymes catalyze or speed up chemical reactions in the body ◼ Plasma membrane proteins can transport substances across the cell membrane, play a role in cell communication, act as enzymes, or help identify the cell to the rest of the body STRUCTURE DETERMINES FUNCTION – CELLULAR LEVEL ◼ Skeletal muscle cells allow them to have the function of contraction, which allows us to move STRUCTURE DETERMINES FUNCTION – CELLULAR LEVEL ◼ Skeletal muscle cells allow them to have the function of contraction, which allows us to move STRUCTURE DETERMINES FUNCTION – CELLULAR LEVEL ◼ A muscle fiber is composed of many fibrils, which give the cell its striated appearance. STRUCTURE DETERMINES FUNCTION – INDIVIDUAL LEVEL ◼ The heart consists of four hollow chambers (atria and ventricles) and is made of cardiac muscle cells. This structure allows the heart to have the function of pumping blood around the body. STRUCTURE DETERMINES FUNCTION – INDIVIDUAL LEVEL ◼ Bones of the skull are heavy and secure to protect brain function. STRUCTURE DETERMINES FUNCTION – INDIVIDUAL LEVEL ◼ The thin air sacs of the lungs permit movement of gases from the lungs to the blood. STRUCTURE DETERMINES FUNCTION – INDIVIDUAL LEVEL ◼ Urinary bladder – thick, transitional epithelium STRUCTURE DETERMINES FUNCTION – INDIVIDUAL LEVEL ▪ This structure is the liver, which has the function of filtering blood and producing bile.  The Human Body… “So God created man in his own image, in the image of God created he him; male and female created he them.” (Genesis 1:27) DEFINITION OF ANATOMY ▪ The study of the structure and shape of the body and body parts and their relationships to one other ▪ from Greek, from ana- ‘up’ + tomia ‘cutting’ (from temnein ‘to cut’). DEFINITION OF PHYSIOLOGY  Study of the normal functioning of a living organism and its component parts -Includes all its physical and chemical processes -from Ancient Greek φύσις (physis), meaning 'nature, origin', and -λογία (-logia), meaning 'study of') ANATOMY – THE STUDY OF FORM  Cadaver dissection  Cutting and separation of tissues to reveal their relationships  Examining structure of the human body  Inspection  Palpation  Auscultation  Percussion  Exploratory surgery  Imaging techniques FIRST AUTOPSY ◼ In the year 1286 we have reference to a human dissection being performed to determine the cause of death. ◼ Today, this procedure is called an autopsy. AUTOPSY ◼ Also called necropsy, postmortem or postmortem examination ◼ The dissection and examination of a dead body, its organs and structures ◼ Means “to see for oneself” and has been in use in reference to determining cause of death by examining a body since the 17th century. ◼ Autopsies are best if performed within 24 hours of death before organs deteriorate and before embalming which can interfere with toxicology and blood cultures. AUTOPSY ◼ An autopsy is usually done to :  Determine the cause of death  Identify diseases not detected during life  Determine the extent of injuries and contribution to death  Identify hereditary conditions NON-INVASIVE DIAGNOSTIC TECHNIQUES  Is often done to access structure and function and to search for the presence of disease. ◼ Inspection consists of visual examination, ◼ Palpation is gently touching body surfaces with hands. ◼ Auscultation is listening to body sounds (stethoscope). ◼ Percussion is tapping on the body surface with fingertips and listening to echoes. NON-INVASIVE DIAGNOSTIC TECHNIQUES EXPLORATORY SURGERY ◼ Surgical investigation to diagnose the cause of a disorder or disease ◼ May become surgeries in which definitive treatment is rendered when a previously undiagnosed lesion is identified and rectified EXPLORATORY SURGERY MEDICAL IMAGING ◼ Allows visualization of structures without surgery ◼ Useful for confirmation of diagnosis ◼ Examples of imaging techniques Conventional Radiography  A single burst of xrays  Produces 2-D image on film  Known as radiography or xray  Poor resolution of soft tissues  Major use is osteology Computed Tomography (CT Scan)  Moving x-ray beam  Image produced on a video monitor of a cross-section through body  Computer generated image reveals more soft tissue detail  kidney & gallstones  Multiple scans used to build 3D views Angiography  Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers.  performed using: ◦ x-rays with catheters ◦ computed tomography (CT) ◦ magnetic resonance imaging (MRI) Right Coronary Angiogram Ultrasound(US)  High-frequency sound waves emitted by hand- held device  Safe, noninvasive & painless  Image or sonogram is displayed on video monitor  Used for fetal ultrasound and examination of pelvic & abdominal organs, heart and blood flow through blood vessels Magnetic Resonance Imaging (MRI) Magnetic resonance imaging  (MRI) is a technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body  Magnetic field temporarily realigns hydrogen atoms in your body.  Radio waves cause these aligned atoms to produce signals  Signals used to create cross- sectional MRI images Positron Emission Tomography (PET) An imaging technique which  uses small amounts of radiolabeled biologically active compounds to help in the diagnosis of disease.  The tracers are introduced into the body, by either injection or inhalation of a gas.  PET scanner is used to produce an image showing the distribution of the tracer in the body.  Clinical applications: Oncology, brain, heart Positron Emission Tomography (PET) ANATOMY  Microscopic vs Macroscopic (Gross) Anatomy  Subspecialties:  Cytology, histology, developmental anatomy/ embryology  Surface anatomy, systemic anatomy, regional anatomy, living anatomy, clinical anatomy, radiographic anatomy, pathologic anatomy CYTOLOGY Image result for "cytology" HISTOLOGY DEVELOPMENTAL ANATOMY/EMBRYOLOGY SURFACE ANATOMY SURFACE ANATOMY SYTEMIC ANATOMY REGIONAL ANATOMY ANATOMY ◼ Living anatomy ◼ Clinical anatomy ◼ Radiographic Anatomy ◼ Pathologic Anatomy  Exploratory Cytology Surgery Histology Medical Imaging Gross Anatomy PHYSIOLOGY science of body functions normal and abnormal adult physiology is studied in this class some genetic variations occur PHYSIOLOGY - SUBSPECIALTIES cellphysiology, systems physiology, pathophysiology, exercise physiology, neurophysiology, endocrinology, cardiovascular physiology, immunophysiology, respiratory physiology, renal physiology, and reproductive physiology STRUCTURAL LEVELS OF ORGANIZATION THE HIERARCHY OF COMPLEXITY  Organism is composed of organ systems  Organ systems composed of organs  Organs composed of tissues  Tissues composed of cells  Cells composed of organelles  Organelles composed of molecules  Molecules composed of atoms STRUCTURAL ORGANIZATION OF MATTER 1. Chemical Level a. Atoms (Proton, Neutron, electrons) b. Molecules (Two or more atoms joined together by either covalent or ionic bonds) Four biologically important organic molecules in the human body a. Proteins which are made from 20 different Amino Acids STRUCTURAL ORGANIZATION OF MATTER Four Biologically-Important Organic molecules: b. Complex Carbohydrates - made from simple sugars c. Nucleic Acids made for nucleotides d. Lipids made from fatty acids and glycerol 2. Cells (Smallest structural and functional units of the human body) STRUCTURAL ORGANIZATION OF MATTER 3. Tissues (group of cells and the materials surrounding them that work together to perform a particular function) 4. Organs (composed of two or more tissues work together to provide specific functions and they usually have specific shapes) STRUCTURAL ORGANIZATION OF MATTER 5. Organ systems (consist of one or more organs that provide a common function) a. Integumentary system b. Skeletal system c. Muscular system d. Nervous system STRUCTURAL ORGANIZATION OF MATTER e. Endocrine system f. Cardiovascular system g. Lymphatic system h. Respiratory system I. Digestive system j. Urinary system k. Reproductive system Figure 1.2.1 TOPIC 2 – THE LIVING BEING Characteristics of Living Beings 6 Basic Life Processes which distinguish living from non-living things BASIC LIFE PROCESSES 1. Metabolism Sum of all biochemical processes of cells, tissues, organs, and organ systems 2. Responsiveness Ability to detect and respond to changes in the internal and external environment 3. Movement Motion; Occurs at the intracellular, cellular, organ levels BASIC LIFE PROCESSES 4. Growth Increase in number of cells, size of cells, tissues, organs, and the body. Single cell to multicellular complex organism 5. Differentiation Process a cell undergoes to develop from a unspecialized to a specialized cell 6. Reproduction Formation of new cells for growth, repair, or replacement, or the production of a new individual. HOMEOSTASIS BASIC LIFE PROCESSES ◼ Homeostasis ◼ Homeo = sameness; -stasis = standing still ◼ Maintaining the internal environment within physiological limits ◼ Equilibrium of the body’s internal environment produced by the interaction of organ systems and regulatory processes (feedback systems). ◼ Homeostasis is a dynamic condition in response to changing conditions. HOMEOSTASIS AND BODY FLUIDS  Compartments for Body Fluids 1. Intracellular 2. Extracellular a. Interstitial -the internal environment b. Plasma* HOMEOSTASIS AND BODY FLUIDS ◼ Body fluids are defined as dilute, watery solutions containing dissolved chemicals inside or outside of the cell. Maintaining the volume and composition of body fluids is important.  Intracellular Fluid (ICF) is the fluid within cells  Extracellular Fluid (ECF) is the fluid outside cells ◼ Interstitial fluid is ECF between cells and tissues HOMEOSTASIS AND BODY FLUIDS ◼ Cellular function depends on the regulation of the composition of the interstitial fluid.  Composition of interstitial fluid changes as substances move between plasma and the interstitial fluid.  Movement back and forth across capillary walls provides nutrients (glucose, oxygen, ions) to tissue cells and removes waste (carbon dioxide). CONTROL OF HOMEOSTASIS ◼ Homeostasis is continually being disrupted by  external stimuli ◼ intense heat, cold , and lack of oxygen  internal stimuli ◼ psychological stresses ◼ exercise ◼ Disruptions are usually mild & temporary ◼ If homeostasis is not maintained, death may result CONTROL OF HOMEOSTASIS  Homeostatic imbalances occur because of disruptions from the external or internal environments.  Homeostasis is regulated by the nervous system and endocrine system, acting together or independently.  The nervous system detects changes and sends nerve impulses to counteract the disruption.  The endocrine system regulates homeostasis by secreting hormones.  Whereas nerve impulses cause rapid changes, hormones usually work more slowly. FEEDBACK SYSTEM ◼ Cycle of events:  Body is monitored and re- monitored.  Variables are parameters that are monitored and controlled or affected by the feedback system/  Each monitored variable is termed a controlled condition.  Body temperature, blood glucose levels, blood pH, blood pressure, oxygen levels FEEDBACK SYSTEM ◼ These variables must stay within certain ranges ◼ Conditions do fluctuate, but within an acceptable range FEEDBACK SYSTEM ◼ Changes in the external environment can cause these variables to change. ◼ Stimulus is any disruption that changes a controlled condition ◼ Three basic components:  Receptor  Control center  Effector Feedback System 86  Afferent pathway  Efferent pathway  Sensory pathway  Motor pathway  Sensory neuron  Motor neuron FEEDBACK SYSTEM ◼ Sensory neuron ◼ Motor neuron (autonomic neuron) 1. FEEDBACK SYSTEM - RECEPTOR ◼ A receptor is a body structure that monitors changes in a controlled condition (such as body temperature) and sends input to the control center. ◼ Specialized nerve endings in the skin act as temperature receptors – they cause a nerve to fire in response to temperature changes. OTHER RECEPTORS ◼ Mechanoreceptors—respond to touch, pressure, vibration, and stretch ◼ Thermoreceptors—sensitive to changes in temperature ◼ Photoreceptors—respond to light energy (example: retina) ◼ Chemoreceptors—respond to chemicals (examples: smell, taste, changes in blood chemistry) ◼ Nociceptors—sensitive to pain-causing stimuli (examples: extreme heat or cold, excessive pressure, inflammatory chemicals) OTHER RECEPTORS OTHER RECEPTORS 2. FEEDBACK SYSTEM – CONTROL CENTER/INTEGRATING CENTER ◆ The control center sets the range of values to be maintained – usually this is done by the brain. ▪ Evaluates input received from receptors and generates output command  Output involves nerve impulses, hormones, or other chemical agents. ◼ Brain acts as a control center receiving nerve impulses from receptors. 2. FEEDBACK SYSTEM – EFFECTOR ◼ The effector receives output from the control center and produces a response or effect that changes the controlled condition.  Nearly every organ or tissue can serve as an effector. ◼ Body temperature drops. ◼ The brain sends an impulse to the skeletal muscles to contract. ◼ Shivering occurs to generate heat. FEEDBACK SYSTEMS ◼ Negative Feedback systems:  Reverses a change in a controlled condition ◼ Positive Feedback systems:  Strengthens or reinforces a change in one of the body’s controlled conditions NEGATIVE FEEDBACK SYSTEMS NEGATIVE FEEDBACK - REVERSE NEGATIVE FEEDBACK SYSTEMS Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.  Example: Brain senses Sweating change in blood temperature 37.5 oC Core body temperature  If too warm, vessels dilate (99.5 oF) Vasodilation (vasodilation) in the skin 37.0 oC Set point (98.6 oF) and sweating begins (heat- losing mechanism) 36.5 oC Vasoconstriction (97.7  If too cold, vessels in the oF) Time skin constrict (vasoconstriction) and shivering begins (heat- Shivering gaining mechanism) NEGATIVE FEEDBACK SYSTEMS ◼ Blood Pressure regulation  External or internal stimulus increases BP.  Baroreceptors (pressure sensitive receptors) detect higher BP and send a nerve impulse to the brain (interpretation).  Responses sent via nerve impulses to the heart and blood vessels cause the BP to drop (homeostasis restored) NEGATIVE FEEDBACK SYSTEMS POSITIVE FEEDBACK SYSTEMS album_georgina1_sm POSITIVE FEEDBACK – Strengthening and Reinforce ◼ Self-amplifying cycle  Leads to greater change in the same direction  Feedback loop is repeated—change produces more change ◼ Normal way of producing rapid changes  Occurs with childbirth, blood clotting, protein digestion, fever, and generation of nerve signals Positive Feedback in Childbirth Next slide POSITIVE FEEDBACK MECHANISM HOMEOSTATIC IMBALANCES  Disruption of homeostasis can lead to disorder, disease, aging and death  Disorder is a general term for any change or abnormality of function.  Disease is a more specific term for an illness characterized by a recognizable set of signs and symptoms.  A local disease is one that affects one part or a limited region of the body.  A systemic disease affects either the entire body or several parts. HOMEOSTATIC IMBALANCES  Disease is a more specific term for an illness characterized by a recognizable set of signs and symptoms.  Signs are objective changes that a clinician can observe and measure; e.g., fever or rash.  Symptoms are subjective changes in body functions that are not apparent to an observer; e.g., headache or nausea.  Diagnosis is the art of distinguishing one disease from another or determining the nature of a disease; a diagnosis is generally arrived at after the taking of a medical history and the administration of a physical examination. THE END