PAR3623_F2024 - Lecture 1.pdf

PAR3623 Paramedicine – Medical Physiology I F2024 Lecture 1 Cellular basis of physiological function - Part 1  Copyright / Intellectual Property Notice Materials posted to courses are subject to Intellectual Property and Copyright...

PAR3623 Paramedicine – Medical Physiology I F2024 Lecture 1 Cellular basis of physiological function - Part 1  Copyright / Intellectual Property Notice Materials posted to courses are subject to Intellectual Property and Copyright protection, and as such cannot be used and posted for public dissemination without prior permission from the College. For clarity, these protections are automatic once a work is created, and applies whether or not a copyright statement appears on the material. Students are bound by College policies, including AA 34 - Copyright, and SA 07 - Student Code of Conduct, and any student found to be using or posting course materials for public dissemination without permission is in breach of these policies and may be sanctioned.  About me Dr. Pasan Fernando § Please address me as either Dr. Fernando or Professor Fernando Office: P112 Office hours: § Please email to request an appointment § Include PAR Med Phys in the subject line – I teach in other programs and will find it hard to identify you otherwise. Dr. Pasan Fernando 3  Need HELP?? If you need help: 1. Email me for an appointment – can meet individually or as a group 2. Chat with me after class Email responses follow the AC policy – 48h grace (not including weekends and holidays) Expect email responses from me during regular College business hours with some exceptions. Ø After the 48h, please send me a polite reminder. J Dr. Pasan Fernando 4  Assessment Tests are a combination of multiple choice and short answer style Value (%) questions. Assessment The short answer questions are Test 1 10 designed to encourage your thinking skills. Test 2 15 It is important to integrate the Test 3 15 information to demonstrate your Assignments 20 understanding of the material Final Exam 40 Assignments are not pre-scheduled and will occur randomly Dr. Pasan Fernando May include in-class quizzes, group activities, video commentaries, written work, etc. 5  Mastering Medical Physiology – PAR 3621 The purpose of PAR3621 is to help you practice and engage with the material covered in Medical Physiology I and II. Labster § Labster is a new learning virtual physiology lab simulation tool implemented for 2024 § You will be performing virtual experiments that compliment the theory that we learn in PAR3623 § Labster is part of PAR3621 – a separate course § Each lab assignment must be completed by the scheduled date. § Your mark in PAR3621 is assigned as either Pass or Fail. Dr. Pasan Fernando https://www.labster.com 6  Muddiest Point – Post Lecture Reflection Dr. Pasan Fernando  Lecture 1 Objectives for Lecture 1: 1. Describe how physiology and body function is integrated – organization with complementarity of structure and function 2. List and describe the necessary functions for function (life) 3. Describe the basic organization of the human body. Dr. Pasan Fernando 4. Describe the fundamental concepts of homeostasis 8  Physiology Defined The study of the functions of an organism TABLE 1.1 Selected Subdisciplines of Physiology and its constituent parts Subdiscipline Study of … Molecular physiology Functions of individual molecules, such as § Human physiology proteins. Cell physiology Functions of cells. Ø Focuses on the human body Neurophysiology Functions of the nervous system. Has many subdisciplines Endocrinology Hormones (chemical regulators in the blood) and how they control body functions. Cardiovascular Functions of the heart, blood vessels, and blood. physiology Immunology How the body defends itself against disease- causing agents. Respiratory physiology Functions of the air passageways and lungs. Renal physiology Functions of the kidneys. Gastrointestinal Functions of the stomach and intestines. physiology Integrative physiology How different parts of the body work together to Dr. Pasan Fernando accomplish a particular function. Exercise physiology Changes in cell and organ functions as a result of muscular activity. Pathophysiology Functional changes associated with disease and aging.  Levels of Organization Human body is very organized, from the smallest chemical level to whole organism level: § Chemical level: atoms, molecules, and organelles § Cellular level: single cell § Tissue level: groups of similar cells § Organ level: contains two or more types of tissues § Organ system level: organs that work closely together § Organismal level: all organ systems combined Dr. Pasan Fernando to make the whole organism 10  Necessary Life Functions Movement § Muscular system allows movement § Sk. Muscles move body parts § Body fluids via cardiac muscles, smooth muscles Responsiveness § Ability to sense and respond to stimuli § Withdrawal reflex prevents injury § Control of breathing rate, changes in response to activity Digestion Metabolism Excretion Dr. Pasan Fernando Reproduction Growth 11  Necessary Life Functions, cont. Differentiation § Describes the development of a cell from an unspecialized to a specialized state § Each type of cell has a specialized structure and function that differs from its precursor cells Ø Ex. RBC (specialized) emerge from an unspecified cell in the bone marrow Maintaining boundaries § Separation between internal and external environments Ø Ex. Plasma membrane separates cells Dr. Pasan Fernando intracellular space from extracellular space Ø Ex. Skin separates organism from environment https://training.seer.cancer.gov/leukemia/anatomy/lineage.html 12  The Pensive Paramedic Growth is a necessary fundamental characteristic of life. Dr. Pasan Fernando 13  Organs and Organ Systems Organs: have at least two tissue types and perform specific functions Organ system: collection of organs performing a particular task 11 organ systems – sometimes counted as 10 or 12 in some sources (Derrickson uses 12) All are vital but none function in isolation Some are physically connected Eg. gastrointestinal, cardiovascular, urinary Some are not connected but widely scattered Dr. Pasan Fernando Eg. endocrine, lymphatic (immune) system All systems are interdependent 14 All systems strive to maintain homeostasis  Eleven Organ Systems Organism level Organ The heart is an level organ containing many tissue types. Cardiovascular System Endocrine Nervous Lymphatic Organ Muscular Respiratory system Skeletal Digestive level Integumentary Urinary Reproductive Dr. Pasan Fernando The cardiovascular system includes the heart and other organs. 15  The Overall Body Plan This section describes how the body can be described into a simple layout Objectives: ü Describe the simple body plan ü Draw the simple body plan with key elements ü Identify critical features of the simple body plan Dr. Pasan Fernando 16  The Overall Body Plan Overall plan of the body can be broken down into a very simplistic model § Consists of: 1. External environment 2. Internal environment Ø Must have a source to exchange air (O2/CO2) Ø Must have a way of taking in nutrients and sending out waste Ø Must have a way of moving the components from air exchange and nutrients around to the rest of the body Dr. Pasan Fernando 17  Internal and External Environments are Separated § Epithelial cells form a layer that separates the external environment from the inside of the body § Skin, linings of the lungs, GI system, kidney tubules – all are continuous with the external environment § Examples of external environment: Ø Surroundings external to the skin Ø Air in the lungs Ø Food in the stomach Ø Urine in the bladder Dr. Pasan Fernando 18  Internal Environment Nutrients, External Air water, environment inorganic ions § Immediate environment of most cells Internal Gastrointestinal environment tract O2 CO 2 Lungs § Includes tissue fluid and plasma Cell Blood vessels Ø Tissue fluid (interstitial fluid) is fluid Secretion membrane Heart Absorption around all other cells Filtration Reabsorption Secretion Blood cells Ø Plasma is fluid around blood cells Cells (nerve, muscle, etc.) Ø In: à nutrients O2 Kidneys Excretion Epithelial Unabsorbed Ø Out: ß waste, CO2 cell layer Urine material Dr. Pasan Fernando CCM Health - Ccm.net 19  Exchange Between Internal and External Environment § Cells exchange nutrients and wastes between internal and external environments § But most cells are not in direct contact with the external environment § Material is exchanged between blood (plasma) Ø Ex. Lungs, GI tract, kidneys – Across gastrointestinal tract » Absorption » Secretion – Across kidneys » Filtration Dr. Pasan Fernando » Reabsorption » Secretion 20  The Pensive Paramedic Barriers are essential for isolating the internal and external environments. § But the cells/tissues/organs of the body do not function in isolation § Physiological function requires a community response § How then does the body function as a community? 1. What is meant by community response? 2. What facilitates a community response? Dr. Pasan Fernando 21  Dr. Pasan Fernando 22  Homeostasis Homeostasis is one of the underlying themes in this course Objectives: ü Identify the body fluids and main compartments in the body ü Describe how solutes are exchanged between compartments ü Describe the major solutes found in the ECF and begin to recognize their normal concentrations Dr. Pasan Fernando 23  Body Fluids and Compartments § Body is divided into compartments 40% solids § Compartments contain fluids § Compartments are separated by epithelial membranes § Membranes are semipermeable § Transport occurs between 2/3 compartments ICF 60% fluids Dr. Pasan Fernando 75% 1/3 Interstital ECF fluid 25% plasma  Key constituents and physical characteristics of extra cellular fluid (ECF) Constituent Normal Value Normal Range Approximate Short-Term Nonlethal Unit Limit Oxygen (venous) 40 25–40 10–1000 mm Hg Carbon dioxide 45 41–51 5–80 mm Hg (venous) Sodium ion 142 135–145 115–175 mmol/L Potassium ion 4.2 3.5–5.3 1.5–9.0 mmol/L Calcium ion 1.2 1.0–1.4 0.5–2.0 mmol/L Chloride ion 106 98–108 70–130 mmol/L Bicarbonate ion 24 22–29 8–45 mmol/L Glucose 90 70–115 20–1500 mg/dl Body temperature 98.4 (37.0) 98–98.8 (37.0) 65–110 (18.3–43.3) °F (°C) Dr. Pasan Fernando Acid–base 7.4 7.3–7.5 6.9–8.0 pH (venous) 25  Homeostasis In this section you will… § Define homeostasis. § Distinguish between the body’s internal environment and external environment. § Describe the components of a feedback system. § Contrast the operation of negative and positive feedback systems. § Explain feedforward control. Dr. Pasan Fernando  Homeostasis – Began as a Concept Claude Bernard (1813-1878) - described how internal environment Walter Cannon (1871-1945) Dr. Pasan Fernando is separate and different from external - 'homeostasis' environment) 'milieu interieur' - underlining principle of physiology 27  Homeostasis § Homeostasis is the maintenance of relatively stable internal conditions despite continuous changes in the (external) environment) Ø A dynamic state of equilibrium, always readjusting as needed Ø All organ systems contribute to maintain homeostasis Homeostatic controls § Work to maintain constant variables in the body Ø i.e., blood sugar, blood volume, temperature etc. § Control of variables involves three components: 1. Receptor 2. Control center Dr. Pasan Fernando 3. Effector 28  Elements of a Homeostatic Control System 3 Input: Information 4 Output: Information sent along afferent Control sent along efferent pathway to control Center pathway to effector. center. Afferent Efferent pathway pathway Receptor Effector 2 Receptor detects change. 5 Response of effector feeds IM back to reduce BA 1 Stimulus LA the effect of NC stimulus and produces E returns variable change in BALANCE to homeostatic variable. level. Dr. Pasan Fernando IM BA LA NC E 29  Homeostasis – Negative Feedback Control Center (thermoregulatory Negative feedback regulation center in brain) Afferent Efferent § Most-used feedback mechanism in pathway pathway body Receptors Temperature-sensitive Effectors § Response reduces or shuts off cells in skin and brain Sweat glands original stimulus IM Sweat glands activated Response BA Evaporation of sweat LA Ø Variable changes in opposite Body temperature rises N CE Body temperature falls; stimulus ends direction of initial change Stimulus: Heat BALANCE § Examples Response Stimulus: Cold IM Body temperature Ø Regulation of body temperature Body temperature rises; BA LA falls stimulus ends N CE (a nervous system mechanism) Ø Regulation of blood glucose by Effectors Receptors Temperature-sensitive Skeletal muscles insulin (an endocrine system cells in skin and brain Dr. Pasan Fernando mechanism) Efferent Afferent Shivering begins pathway pathway Control Center (thermoregulatory center in brain) 30  Homeostasis – Positive Feedback 1 Break or tear Positive feedback occurs in blood vessel wall. § Response enhances or exaggerates the original stimulus Positive feedback § May exhibit a cascade or amplifying effect cycle is initiated. as feedback causes variable to continue in same direction as initial change 3 Released 2 Platelets § Usually controls infrequent events that do chemicals attract more Positive adhere to site and release not require continuous adjustment, for platelets. feedback loop chemicals. example: Ø Enhancement of labor contractions by oxytocin Feedback cycle ends Ø Platelet plug formation and blood when plug is formed. clotting Dr. Pasan Fernando 4 Platelet plug is fully formed. 31  Homeostatic Regulation Homeostatic control is not precise Air Air Ø Maintains a normal range around the set conditioner conditioner point turns on turns off Ø Actual value oscillates Set point For example: – House thermostat set at 72°F (22 °C) – Actual temperature in the house ranges a Normal range few degrees above and below that set point Dr. Pasan Fernando 32  Homeostasis in Reality Human physiological systems rely on antagonistic controls to maintain homeostasis Dr. Pasan Fernando These are independent regulators that exert opposite effects Ø eg. temperature is controlled through both heat production and heat dissipation  Homeostatic Imbalance Disturbance of homeostasis § Increases risk of disease § Contributes to changes associated with aging Ø Control systems become less efficient § If negative feedback mechanisms become overwhelmed, destructive positive feedback mechanisms may take over – E.g. Heart failure Dr. Pasan Fernando 34  v Based on your current understanding of A&P, provide examples that support the theme of form-fits-function. v Describe the levels of structural organization within the human body. v Provide examples of how body functions are integrated. v What are the 11 organ systems? Provide examples of how they support one another. v What critical elements are required in the basic body plan? Dr. Pasan Fernando v Contrast the mechanisms of positive vs negative feedback homeostasis. 35  Dr. Pasan Fernando 36  Essentials of Anatomy – Independent Review Ø In-class teaching of anatomy is less of an emphasis in this course. Ø However, a basic understanding of anatomy is still required to discuss medical physiology. Ø Review the following slides. You are responsible for this information. Dr. Pasan Fernando Ø Don’t hesitate to connect with me if you need more help or would like a recap. 37  The Anatomical Position Anatomical Position: § Standing up § Hands at the sides § Palms facing forward, thumbs pointing away from body § Feet slightly apart § Eyes forward Dr. Pasan Fernando Anterior Posterior 38  Directional Terms Superior Cranial or Cephalic Proximal § Directional terms describe one Posterior Anterior body structure relative to or Dorsal or Ventral another § Based on the anatomical Lateral Medial position § Right and left refer to the body Proximal Caudal being viewed, not right and left Distal Right Left of the observer Dr. Pasan Fernando Distal Inferior Anterior view Lateral view 39  Dr. Pasan Fernando 40 Dr. Pasan Fernando Dr. Pasan Fernando  Regional Terms Two major divisions of body § Axial Ø Head, neck, and trunk § Appendicular Ø Limbs (legs and arms) § Regional terms designate specific areas within body divisions Dr. Pasan Fernando  Body Planes and Sections Body planes § Surfaces along which body or structures may be cut for anatomical study § Three most common planes: Ø Sagittal plane Ø Frontal (coronal) plane Ø Transverse (horizontal) plane Sections § Cuts or sections made along a body plane Ø Named after plane, so a sagittal cut results in a sagittal section Dr. Pasan Fernando https://my-ms.org/mri_planes.htm 44  Sagittal Plane Sagittal plane § Divides body vertically into right and left parts § Produces a sagittal section if cut along this plane § Midsagittal (median) plane Ø Cut was made perfectly on midline § Parasagittal plane Ø Cut was off-centered, not on midline AA DA Dr. Pasan Fernando LA RV https://www.ceessentials.net/article40.html 45 Median (midsagittal) plane Frontal (coronal) plane Transverse plane Vertebral Right Left column lung Heart lung Liver Aorta Pancreas Spleen  Frontal/Coronal Plane Frontal (coronal) plane § Divides body vertically into anterior and posterior parts (front and back) § Produces a frontal or coronal section Dr. Pasan Fernando sagittal) plane Frontal (coronal) plane Transverse plane ebral Right Left 46 mn lung Heart lung Liver Aorta Pancreas Spleen  Transverse Plane Transverse (horizontal) plane § Divides body horizontally (90° to vertical plane) into superior and inferior parts (top and bottom) § Produces a cross section Oblique section § Result of cuts at angle other than 90° to vertical plane Dr. Pasan Fernando Frontal (coronal) plane Transverse plane http://y7177.com/sa/anato/uro/kidney/kidney.htm 47 ht Left g Heart lung Liver Aorta Pancreas Spleen  The Pensive Paramedic Identify the following sectional planes Dr. Pasan Fernando http://breathe.ersjournals.com/content/9/1/36 48  Body Cavities § Body contains internal cavities that are closed to environment § Cavities provide different degrees of protection to organs within them § Two sets of cavities Ø Dorsal body cavity Ø Ventral body cavity Dr. Pasan Fernando https://study.com/academy/lesson/dorsal-body-cavity-definition-organs-membranes.html 49  Dorsal and Ventral Body Cavities Dorsal body cavity Cranial Cranial cavity § Protects fragile nervous system cavity (contains brain) § Two subdivisions Vertebral cavity Ø Cranial cavity Dorsal body Superior mediastinum Thoracic cavity – Encases brain cavity Pleural (contains cavity heart and Pericardial Ø Vertebral cavity lungs) cavity within the mediastinum – Encases spinal cord Vertebral cavity Diaphragm Ventral body (contains cavity (thoracic and Ventral body cavity spinal cord) Abdominal cavity (contains digestive viscera) Abdomino- pelvic abdomino- pelvic cavities) cavity § Houses the internal organs Pelvic cavity (collectively called viscera) Dorsal body cavity (contains urinary bladder, reproductive organs, and rectum) § Two subdivisions, which are Ventral body cavity Lateral view Anterior view separated by the diaphragm Dr. Pasan Fernando Ø Thoracic cavity Ø Abdominopelvic cavity 50  Ventral Body Cavity – Thoracic cavity Thoracic cavity Cranial Cranial cavity § Two pleural cavities cavity (contains brain) Ø Each cavity surrounds one Vertebral cavity lung Dorsal Superior body mediastinum Thoracic § Mediastinum cavity cavity Pleural (contains cavity Ø Contains pericardial cavity heart and lungs) Pericardial cavity within Ø Surrounds other thoracic the mediastinum Vertebral cavity Diaphragm Ventral body organs, such as esophagus, (contains spinal cavity (thoracic and Abdominal cavity trachea, etc. cord) (contains digestive viscera) Abdomino- pelvic abdomino- pelvic cavities) cavity § Pericardial cavity Pelvic cavity (contains urinary Ø Encloses heart Dorsal body cavity bladder, reproductive organs, and rectum) Dr. Pasan Fernando Ventral body cavity Lateral view Anterior view 51  Ventral Body Cavity – Abdominopelvic cavity Cranial Abdominopelvic cavity Cranial cavity (contains cavity § Abdominal cavity brain) Vertebral cavity Ø Contains stomach, Superior Dorsal intestines, spleen, and body cavity Thoracic cavity mediastinum Pleural liver (contains heart and cavity Pericardial lungs) cavity within Pelvic cavity Vertebral the mediastinum cavity Diaphragm Ventral body Ø Contains urinary (contains cavity (thoracic and spinal Abdominal cavity bladder, reproductive cord) (contains digestive viscera) Abdomino- pelvic abdomino- pelvic cavities) organs, and rectum cavity Pelvic cavity (contains urinary Dorsal body bladder, reproductive cavity organs, and rectum) Dr. Pasan Fernando Ventral body cavity Lateral view Anterior view 52  Membranes Within Body Cavities Membranes in ventral body cavity § Serosa (also called serous membrane) Ø Thin, double-layered membranes that cover Outer balloon wall surfaces in ventral body cavity (comparable to parietal serosa) – Parietal serosa lines internal body cavity Air (comparable to serous cavity) walls Inner balloon wall – Visceral serosa covers internal organs (comparable to visceral serosa) (viscera) A fist thrust into a flaccid balloon demonstrates the relationship between the parietal and visceral Ø Double layers are separated by slit-like cavity serous membrane layers. filled with serous fluid Ø Fluid secreted by both layers of membrane Heart Dr. Pasan Fernando Parietal pericardium 53 Pericardial space with serous fluid Visceral pericardium  Outer balloon wall (comparable to parietal serosa) Air (comparable to serous cavity) Membranes Within Body Cavities Inner balloon wall (comparable to visceral serosa) A fist thrust into a flaccid balloon demonstrates the relationship between the parietal and visceral serous membrane layers. Heart Membranes in the ventral cavity Parietal pericardium § Named for specific cavity and organs Pericardial space with that they are associated with serous fluid Visceral pericardium Ø Pericardium – Heart The serosae associated with the heart. Ø Pleurae – Lungs Ø Peritoneum – Abdominopelvic cavity Dr. Pasan Fernando 54  Abdominopelvic Quadrants and Regions Abdominopelvic quadrants and regions § Quadrants are divisions used primarily by medical personnel Ø Abdominopelvic region is sectioned into quarters – Right upper quadrant (RUQ) – Left upper quadrant (LUQ) – Right lower quadrant (RLQ) – Left lower quadrant (LLQ) Right Left Upper Upper Quadrant Quadrant (RUQ) (LUQ) Dr. Pasan Fernando Right Lower Left Lower Quadrant Quadrant (RLQ) (LLQ) 55  Clinicians vs. Anatomists Right Left Right Left hypochondriac Epigastric hypochondriac Upper Upper region region region Quadrant Quadrant (RUQ) (LUQ) Right lumbar Umbilical Left lumbar region region region Right Lower Left Lower Quadrant Quadrant Right inguinal Hypogastric Left inguinal (RLQ) (LLQ) region (pubic) region region The four abdominopelvic quadrants The nine abdominopelvic regions Dr. Pasan Fernando 56 Dr. Pasan Fernando HLTH3303 57  Other Body Cavities § In addition to the two main body cavities, the body has several smaller cavities that are exposed to environment Ø Oral and digestive cavities Ø Nasal cavity Ø Orbital cavities Ø Middle ear cavities § Not exposed to environment § Synovial cavities: joint cavities Dr. Pasan Fernando 58  v Describe the anatomical position v What type of section would separate the left and right portions of the heart? What type of cut would separate the atria from the ventricles? v Identify two anatomical structures/organs in the dorsal cavity. v Distinguish between the thoracic and pelvic cavities. v Which body cavities are in immediate threat from the external environment? Dr. Pasan Fernando What organ system is particularly important in these regions? 59