2Relationship Between Anatomy and Physiology Introduction to Anatomy and PhysiologyRelationship Between Anatomy and Physiology
3Relationship between Anatomy and Physiology The study of internal and external structures of the body and the physical relationships among body partsPhysiologyThe study of how living organisms perform their vital functionsSomeone studying anatomy might examine how and where a particular muscle attaches to the skeleton, whereas someone studying physiology might consider how a muscle contracts or what forces a contracting muscle exerts on the skeleton
4Relationship between Anatomy and Physiology Anatomical info provides clues about functions (physiology), and physiological mechanisms can be explained only in terms of the underlying anatomyALL SPECIFIC FUNCTIONS ARE PERFORMED BY SPECIFIC STRUCTURES!!!!!
5Relationship between Anatomy and Physiology Anatomy can be divided into gross (macroscopic) anatomy and microscopic anatomyGross AnatomyExamination of relatively large structuresUsually visible with unaided eye5 different forms of gross anatomySurface anatomyStudy of general form and superficial markingsRegional anatomyAnatomical organization of specific areas of body (head, neck, trunk)
6Relationship between Anatomy and Physiology 5 different forms of gross anatomy (con’t)Systemic anatomyStudy of the structure of organ systems (skeletal system, muscular system, cardiovascular system, etc.)Developmental anatomyDescribes the changes in form that occur between conception and physical maturityEmbryology – study of early developmental processesClinical anatomySubspecialities important in clinical practiceMedical anatomy (anatomical features that change during illness)Radiographic anatomy (anatomical structures seen using imaging techniques)
7Relationship between Anatomy and Physiology Microscopic AnatomyStudy of structures that cannot be seen without magnificationHas 2 major divisionsCytology – analysis of the internal structure of individual cellsHistology – examination of tissues
8Relationship between Anatomy and Physiology The study of the function of anatomical strucuresCan be divided into 4 major specialtiesCell physiology – study of the function of cellsChemical processes within cells and chemical interactions between cellsSpecial physiology – study of the physiology of specific organsSystemic physiology – study of the functioning of specific organ systemsPathological physiology – study of the effects of diseases on organ or system fuctions
9Levels of Organization Introduction to Anatomy and PhysiologyLevels of Organization
10Levels of Organization The Chemical (or Molecular) LevelAtoms can combine to form molecules with complex shapesThe functional properties of a particular molecule are determined by its unique 3D shapeThe Cellular LevelMolecules interact to form organelles, each of which has specific functions.Organelles are grouped to form cellsThe Tissue LevelGroups of cells working together to perform specific functionsHeart muscle cells interact with other types of cells and extracellular materials to form cardiac muscle tissue
11Levels of Organization The Organ LevelTwo or more tissues working in combination to perform several functionsCardiac muscle tissue, in combination with connective tissue from the bulk of the heart.The Organ System LevelTwo or more organs interactingThe heart and blood vessels work together to form the cardiovascular system.The Organism LevelHighest level of organizationAll organ systems working together
13Introduction to Anatomy and Physiology HomeostasisIntroduction to Anatomy and Physiology
14HomeostasisOne of the roles of the organ systems in an organism is to maintain homeostasis.Homeostasis – maintaining a stable internal environment.Absolutely vital to survivalHomeostatic regulation – adjustment of physiological systems to preserve homeostasis.
15Homeostasis 2 mechanisms of homeostasis Autoregulation (intrinsic regulation) – when a cell, tissue, organ or organ system adjusts its activities automatically in response to an environmental changeEx: when blood oxygen levels decrease in a tissue, the cells release a chemical that dilate local blood vessels. This increases blood flow and, therefore, oxygen.
16Homeostasis 2 mechanisms of homeostasis (con’t) Extrinsic regulation – from activities of the nervous and/or endocrine systems.Ex: During exercise, your nervous system increases heart rate so that blood will circulate faster. Will also decrease blood flow to less active organs.
17HomeostasisThe nervous system directs rapid, short-term, and very specific responsesResponse to placing hand on a hot stoveEndocrine system releases hormones that affect tissues and organs throughout the body.Not immediate, not specific, may be long-term
18Homeostasis Homeostatic regulatory mechanism consists of 3 parts Receptor – sensor that is sensitive to a particular change in environmentControl center – receives and processes info from receptor and sends out commandsEffector – cell or organ that responds to the commands from control center.Similar to thermostat in your house
19Homeostasis Negative feedback Most regulatory mechanisms involve this opposition to changing conditionsExample is body temperature control (thermoregulation)Control center is the hypothalamus region of the brainHypothalamus receives info from two receptors: skin receptors and one in hypothalamusNormal body temp is 98.6o. If temp increases, the control center targets two effectors:muscles in the walls of the blood vessels supplying the skinsweat glands
20Homeostasis Negative feedback (con’t) The muscles in the skin blood vessels relax, increasing blood flow to skin.Sweat glands increase their secretionThe skin acts like a radiator by losing heat to the environmentEvaporation of sweat speed the processAs temp returns to normal, temp at hypothalamus declines, and the control center becomes less activeBlood flow and sweat production return to normal.
21HomeostasisThere are variations in normal homeostatic levels between individuals95% of population has body temp between 36.7oC and 37.2oCPhysicians must keep this in mind when treating patients.
22Homeostasis Positive feedback Produces a response that enhances the change in the original conditions.Usually produces extreme responsesWhat if your thermostat was connected to your heater instead of your air conditioner?What would occur if the temp in your house increased?When temp exceeds set point, thermostat would turn on the heater, and it would continue to run until someone turned off the thermostat, heater, or intervened in some other way.This escalating cycle is called a positive feedback loop
23Homeostasis Positive feedback (con’t) In your body, these loops are found when a potentially dangerous process must be completed quickly before homeostasis can be restored.Ex: immediate danger from a severe cut will decrease blood pressure and reduce efficiency of the heartThe response is to clot the blood.Each step in the process accelerates the process until a clot is formedLabor and delivery of a baby is another example
25Introduction to Anatomy and Physiology Frames of Reference for Anatomical StudiesIntroduction to Anatomy and Physiology
26Frames of Reference for Anatomical Studies Early anatomists faced communication problems.A “bump on the back” doesn’t give very precise info about its locationProminent anatomical structures serve as landmarks, distances are measured in centimeters, and specialized directional terms are used
27Frames of Reference for Anatomical Studies Superficial AnatomyAnatomical landmarks are used in reference to the anatomical positionAnatomical position – hands at side, palms facing forward, and feet togetherDescriptions given are in reference to the anatomical position, unless otherwise notedProne – lying face down in the anatomical positionSupine – lying face up in the anatomical position
29Frames of Reference for Anatomical Studies Anatomical RegionsAbdominopelvic quadrantsFormed by a pair of lines that intersect at the umbilicus (naval)Used by physicians to help determine possible cause of aches, pains, injuries.Internal organs can be found in different quadrantsAbdomiopelvic regionsMore specific than quadrantsPreferred by anatomists
31Frames of Reference for Anatomical Studies Anatomical DirectionsThe terms left and light always refer to the left and right sides of the subject, NOT of the observer
32Frames of Reference for Anatomical Studies Sectional AnatomySometimes the best way to understand anatomy is to slice through it and look at the internal organizationUseful with imaging techniquesRadiologists use these when looking at films
33Frames of Reference for Anatomical Studies Planes and SectionsTransverse plane – right angle to long axis of object, dividing it into superior and inferiorA cut in this plane is called a transverse sectionFrontal plane – parallel to long axis; extends from side to side, dividing the body into anterior and posteriorA cut in this plane is called a frontal sectionSagittal plane – parallel to long axis; extends from front to back, dividing the body in to left and rightA cut down the midline is called a midsagittal sectionParallel cuts are called parasagittal sections
34Frames of Reference for Anatomical Studies Body cavitiesInternal chambers where many vital organs can be found2 functionsProtect organsPermit change of size and shape of the organsYour diaphragm divides your torso into two cavitiesThoracic cavityAbdominopelvic cavityViscera – organs enclosed (fully or partially) by these cavities
35Frames of Reference for Anatomical Studies Body cavities (con’t)Thoracic cavityContains lungs and heart, associated organs of respiratory, cardiovascular, and lymphatic system; lower esophagus; thymusBoundaries are the ribs and diaphragmSubdivided into left and right pleural cavities, which each contain a lung.Contains pericardial cavity, which surrounds the heart
36Frames of Reference for Anatomical Studies Body cavities (con’t)Abdomiopelvic cavityExtends from diaphragm to pelvisDivided into a superior abdominal cavity and an inferior pelvic cavityThe peritoneal cavity surrounds the abdominal and pelvic cavities
37Frames of Reference for Anatomical Studies Body cavities (con’t)Abdominal cavity contains the liver, stomach, spleen, small intestine, and most of the large intestineThe kidneys and pancreas lie posteriorly between the peritoneal cavity and the muscles of the abdominal cavityThe pelvic cavity contains distal large intestine, urinary bladder, and various reproductive organs