M01 Notes PDF - Anatomy & Physiology

1.1 Form and Function of Anatomy & Physiology Anatomy – Study of the structure of body parts and their relationship to one another – Answers question What is that? à That is anatomy Physiology – Study of the function of body parts; how they work to carry out life-su...

1.1 Form and Function of Anatomy & Physiology Anatomy – Study of the structure of body parts and their relationship to one another – Answers question What is that? à That is anatomy Physiology – Study of the function of body parts; how they work to carry out life-sustaining activities – Answers question What does it do? à That is Physiology Topics of Anatomy Subdivisions of anatomy: – Gross or macroscopic anatomy is the study of large, visible structures – Microscopic – Regional anatomy looks at all structures in a particular area of the body Ex-Headà Brain, Eyes, Jaw – System Anatomy looks at just one system – cardiovascular, nervous, muscular, etc. – Surface anatomy looks at internal structures as they relate to overlying skin – visible muscle masses or veins seen on the surface – Structures on or through the skin Topics of Anatomy (cont.) Subdivisions (cont.) – Microscopic anatomy deals with structures too small to be seen by naked eye Cytology: microscopic study of cells  – Cyto = cells Histology: microscopic study of tissues – Histo = tissues – Developmental anatomy studies anatomical and physiological development throughout life Embryology: study of developments before birth To study anatomy, one must know anatomical terminology and be able to observe, manipulate, palpate, and auscultate – Palpate: to feel – Auscultate: to listen (ex- stethoscope) – Manipulate: Move Topics of Physiology Subdivisions of physiology – Based on organ systems e.g., renal or cardiovascular physiology Renal: How do kidneys work? Cardiovascular: How does the heart work? – Often focuses on cellular and molecular levels of the body Looks at how the body’s abilities are dependent on chemical reactions in individual cells To study physiology, one must understand basic physical principles – Electrical currents: They travel through muscles, nerves – Pressure: – Movement – as well as basic chemical principles Complementarity of Structure and Function Anatomy and physiology are inseparable  – Function always reflects structure ALWAYS RELATED – What a structure can do depends on its specific form Even a change in the structure can also influence how much the object functions as well – Known as the principle of complementarity of structure and function the structure of a biological component, like an organ or cell, directly determines its function, meaning the way something is built dictates what it can do; essentially, "form follows function" in the biological world. 1.2 Structural 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: bunch of cells that have a combined function groups of similar cells 1.2 Structural Organization – Organ level (bones, blood vessels, stomach) contains two or more types of tissues – Organ system level organs that work closely together – Ex: heart and lungs=respiratory system – Organismal level: all organ systems combined to make the whole organism 1.3 Requirements for Life Necessary Life Functions  Maintenance of life involves: 1. Maintaining boundaries: Separation between internal and external environments must exist 2. Movement: Both large and small-scale movements (muscle based and celluar movement) 3. Responsiveness: Need to be able to sense something in order to respoibnd to it, reflexes 4. Digestion: To digest is to "break down" or to dismantle. We need to be able to absorb the smaller components 5. Metabolism: The body's chemistry. Catabolism + Anabolism= Metabolic (he total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes) § Ana: Using chemistry to put things together § Cata: Using chemistry to break things apart 6. Excretion: Getting rid of waste products (ex: co2) 7. Reproduction: Of the body and of the cells 8. Growth: Of both cells and organisms Necessary Life Functions 1. Maintaining boundaries – Separation between internal and external environments must exist Plasma membranes separate cells Skin separates organism from environment Humans are multicelluar, so to function, individual cells must be kept alive. organ systems are designed to srvivce the celss all cells dpend on organ systems to meet their survival needs 11 organ systen to maintain life Necessary Life Functions 2. Movement  – Muscular system allows movement Of body parts – skeletal muscles create movement at joints Of substances – cardiac muscle » Moves blood through the arteries – and smooth muscle » Moves products of digestion and urination Contractility refers to movement at the cellular level Necessary Life Functions (cont.) 3. Responsiveness – Ability to sense and respond to stimuli Withdrawal reflex prevents injury Control of breathing rate 4. Digestion – Breakdown of ingested food followed by absorption of simple molecules into blood Necessary Life Functions (cont.) 5. Metabolism – All chemical reactions that occur in body cells Sum of all catabolism and anabolism 6. Excretion – Removal of wastes from metabolism and digestion Urea carbon dioxide feces  Necessary Life Functions (cont.) 7. Reproduction – At the cellular level, reproduction involves division of cells for growth or repair – At the organismal level, reproduction is the production of ofspring 8. Growth – Increase in size of a body part or of organism Necessary Life Functions (cont.) Humans are multicellular, so to function, individual cells must be kept alive – Organ systems are designed to service the cells – All cells depend on organ systems to meet their survival needs There are 11 organ systems that work together to maintain life – Represented in the images that follow… – IInterstitial= between 1. Integumentary System Forms the external body covering protects deeper tissues from injury Synthesizes vitamin D Acts as a barrier Houses – cutaneous receptors – sweat glands – oil glands 2. Skeletal System Protects and supports body organs Provides a framework the muscles  Bone ends create joints that allow movement Blood cells are formed within bones. Bones store minerals. 3. Muscular System Allows manipulation of the environment Locomotion Facial expressions Maintains posture Produces heat 4. Nervous System As the fast-acting control system of the body responds to internal and external changes by activating appropriate muscles and glands. 5. Endocrine System Glands secrete hormones that regulate processes – Growth – Reproduction – Nutrient use – Metabolism by body cells. 6. Cardiovascular system Blood vessels transport blood which carries – Oxygen (O2) – Carbon dioxide (CO2) – Nutrients – Wastes The heart pumps blood.  7. Lymphatic System and Immune System The Lymphatic System – Picks up fluid leaked from blood vessels and returns it to blood. – Disposes of debris in the lymphatic stream. – Houses white blood cells (lymphocytes) involved in immunity. The Immune System – mounts the attack against foreign (non-self) substances within the body. 8. Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs. 9. Digestive System Breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstufs are eliminated as feces. 10. Urinary System Eliminates nitrogenous wastes from the body. Regulates – Water – Electrolytes – Acid-base balance of the blood 11a. Reproductive System: Male Overall function is production of ofspring Testes produce sperm and male sex hormone – testosterone Male ducts and glands aid in delivery of sperm to the female reproductive tract during sexual reproduction 11b. Reproductive System: Female  Overall function is production of ofspring. Ovaries – produce eggs and female sex hormones Estrogen Progesterone The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn. Survival Needs Humans need several factors for survival that must be in the appropriate amounts; too much or too little can be harmful: – Nutrients: Carbs, proteins, fats, minerals, vitamins – Oxygen: Used on a cellular level to create resources – Water: Most abundant compound in the body; used as a component in bodily fluids – Normal body temperature: Should be around 98.6 F/ 37 C (Required to maintain at a particular level to function optimally) Homeostatic mechanisms ae used to keep our body in the range – Appropriate atmospheric pressure: Necessary for breathing and gas exchange (atmosphere will push air into our lungs Survival Needs (cont.) Nutrients – Chemicals for energy and cell building Carbohydrates – major source of energy Proteins – needed for cell building and cell chemistry Fats  – long-term energy storage Minerals and vitamins – involved in chemical reactions as well as for structural purposes Survival Needs (cont.) Oxygen – Essential for release of energy from foods The body can survive only a few minutes without oxygen Water – Most abundant chemical in body; provides the watery environment needed for chemical reactions Also is fluid base for secretions and excretions Survival Needs (cont.) Normal body temperature – If body temp falls below or goes above 37°C, rates of chemical reactions are afected Appropriate atmospheric pressure – Specific pressure of air is needed for adequate breathing and gas exchange in lungs 1.4 Homeostasis Homeostasis is the maintenance of relatively stable internal conditions despite continuous changes in environment – A dynamic state of equilibrium, always readjusting as needed – Maintained by contributions of all organ systems Homeostatic Controls Body must constantly be monitored and regulated to maintain homeostasis – Multiple overlapping systems play a major role in maintaining homeostasis  Nervous system and Endocrine have largest roles Singles cell ables to send signals from point A to point b: neurons Chemicals that circulate in bloodstream: Hormones – Variables are factors that can change and need to be kept within range blood sugar: range that is optimal body temperature: range that is optimal blood volume: range that is optimal (BP, needs to be at optimal level to circulate blood the proper way without causing damage Homeostatic Controls Homeostatic control of variables involves three components: – Receptor Something that can sense change (temperate, chemical) Will depend on which system. They will send information to control center – Control center: CNS (brain, spinal cord), decided if action needs to be taken, sends to efector – Efector Does the action of fixing the problem once the message is received Homeostatic Controls (cont.) Receptor (sensor) – Monitors environment – Pressure, heat, and chemicals are things they are sensitive to – Responds to stimuli things that cause changes in controlled variables Homeostatic Controls (cont.) Control center: Determines the response (does not perform response) – Determines set point at which variable is maintained – Receives input from receptor – Determines appropriate response Homeostatic Controls (cont.)  Ebector – Receives output from control center – Provides the means to respond Muscles – Skeletal muscle – Smooth muscle – Cardiac Muscle Glands – Response reduces output (negative feedback) (absent) (turn of when you hit your goal/ set point) or enhances output (positive feedback) (present) (no set point, just keeps going until runs out of energy) ex: healing a would the body piles on plateletsuntil the run out Homeostatic Controls (cont.) Negative feedback – Most-used feedback mechanism in body – Response reduces or shuts of original stimulus Variable changes in opposite direction of initial change – Examples Regulation of body temperature – a nervous system mechanism Regulation of blood glucose by insulin – an endocrine system mechanism Homeostatic Controls (cont.) Example of negative feedback:  – Chemoreceptors (Receptors) sense decreased glucose levels (Receptor sensitive to glucose) – Control Center determines glucose is out of range: too low. Sends a message to efectors (glands in pancreas) – Glands (Ebectors) release the hormone glucagon. (Insulins opposite) (brings blood glucose levels up) Glucose levels go up. (until a certain level= negative feedback) – Chemoreceptors send message that glucose levels are within range – Control center sends message to pancreas to STOP releasing glucagon. – Glucose is within range. Homeostatic Controls (cont.) Positive feedback – Response enhances or exaggerates the original stimulus – May exhibit a cascade or amplifying efect as feedback causes variable to continue in same direction as initial change – Usually controls infrequent events that do not require continuous adjustment, for example: Enhancement of labor contractions by oxytocin Platelet plug formation and blood clotting Homeostatic Imbalance (umbrella term that refers to anything out of balance) When homeostasis is disturbed, – it increases the risk of disease – It contributes to changes associated with aging Control systems become less eficient – If negative feedback mechanisms become overwhelmed, destructive positive feedback mechanisms may take over Heart failure 1.5 Anatomical Terms Anatomical Position and Directional Terms Standard anatomical position – Body erect, feet slightly apart, palms facing forward with thumbs pointing away from body Directional terms describe one body structure in relation to another body structure – Direction is always based on standard anatomical position – Right and left refer to the body being viewed, not right and left of observer Regional Terms Two major divisions of body – Axial (axis) Head, neck, and trunk (all of the stuf within these too. Extrimities not included in this) – Appendicular Limbs (legs and arms) Regional terms designate specific areas within body divisions Body Planes and Sections Body planes – Surfaces along which body or structures may be cut for anatomical study – Three most common planes: Sagittal plane Frontal (coronal) plane Transverse (horizontal) plane Sections – Cuts or sections made along a body plane Named after plane, so a sagittal cut results in a sagittal section – Body Planes and Sections (cont.) Sagittal plane  Divides body vertically into right and left parts Produces a sagittal section if cut along this plane – Midsagittal (median) plane Cut was made perfectly on midline – A 50% right/50% left cut – Parasagittal plane Cut was of-center, not on midline – A 60% right/40% left cut Body Planes and Sections (cont.) Frontal (coronal) plane – Divides body vertically into anterior and posterior parts (front and back) – Produces a frontal or coronal section (used interchangeably) Body Planes and Sections (cont.) Transverse (horizontal) plane – Divides body horizontally (90° to vertical plane) into superior and inferior parts (top and bottom) – Produces a cross section Body Planes and Sections (cont.) Oblique section (mean not vertical and not horizontal) – Result of cuts at angle other than 90° to vertical plane – Anything cut in between 1-89 degrees (diagonal) 1.6 Body Cavities and Membranes Body contains internal cavities that are closed to environment Cavities provide diferent degrees of protection to organs within them Two sets of cavities – Dorsal body cavity  – Ventral body cavity Dorsal Body Cavity Protects fragile nervous system Two subdivisions – Cranial cavity Encases brain – Vertebral cavity Encases spinal cord Ventral Body Cavity Houses the internal organs (collectively called viscera) Two subdivisions, which are separated by the diaphragm – Thoracic cavity – Abdominopelvic cavity Ventral Body Cavity (cont.) Thoracic cavity – Two pleural cavities Each cavity surrounds one lung Membranes surround lungs – Mediastinum (middle sternum) Contains pericardial cavity Surrounds other thoracic organs, such as esophagus, trachea, etc. – Pericardial cavity Encloses heart Ventral Body Cavity (cont.) Abdominopelvic cavity – Abdominal cavity  Contains – Stomach – Intestines – Spleen – Liver – Pelvic cavity Contains – urinary bladder – reproductive organs – rectum Ventral Body Cavity (cont.) Membranes in ventral body cavity – Serosa (also called serous membrane) (closed cavity) Exposed to surface: Cutaneous or muscus membrane Thin, double-layered membranes that cover surfaces in ventral body cavity – Parietal serosa lines internal body cavity walls – Visceral serosa covers internal organs (viscera) (Theses two terms tell you where its located) Double layers are separated by slit-like cavity filled with serous fluid Fluid secreted by both layers of membrane Ventral Body Cavity (cont.) Named for specific cavity and organs that they are associated with – Pericardium Heart – Pleurae  Lungs – Peritoneum Abdominopelvic cavity Homeostatic Imbalance Serous membranes can become inflamed as a result of infection or other causes Normally smooth layers can become rough and even can stick together, resulting in excruciating pain Examples: pleurisy and peritonitis Ventral Body Cavity (cont.) Abdominopelvic quadrants and regions – Quadrants are divisions used primarily by medical personnel Abdominopelvic region is sectioned into quarters – Right upper quadrant (RUQ) – Left upper quadrant (LUQ) – Right lower quadrant (RLQ) – Left lower quadrant (LLQ) Ventral Body Cavity (cont.) Abdominopelvic quadrants and regions (cont.) – Nine divisions called regions, resembling a tic-tac-toe grid, are used primarily by anatomists Right hypochondriac region Epigastric region Left hypochondriac region Right lumbar region Umbilical region Left lumber region Right Iliac (inguinal) region  Hypogastric region Left iliac (inguinal) region Other Body Cavities In addition to the two main body cavities, the body has several smaller cavities that are exposed to environment – Oral and digestive cavities – Nasal cavity – Orbital cavities – Middle ear cavities – Non have serous (closed) membrane – These have mucosal (open cavity) membrane Not exposed to environment – Synovial cavities: joint cavities