Anatomy & Physiology Anatomy – studies the structure of body parts and their relationship to one another Physiology – function of the body’s structural machinery or how all the body parts work and carry out their life-sustaining activities

Topics in Anatomy Gross anatomy - study of large body structures visible to the naked eye EX: heart, kidneys, etc Regional anatomy – all the structures in one particular region of body Systemic – the gross anatomy is studied system by system Surface anatomy – the study of internal body structures as they relate to the overlying skin surface

Topics in Anatomy – cont’d Microscopic anatomy – structures too small to be seen with the naked eye Cytology – study of the cells of the body Histology – study of the body tissue Developmental anatomy – traces structural changes that occur in the body throughout the life span

Levels of structural organization 1. Chemical level – atoms combine to form molecules like water, sugar, and proteins 2. Cells – All cells have some common functions, but only certain cell types form certain tissue

Levels of structural organization 3. Tissue level – groups of cells that have a common function 4 basic types Epithelium Muscle Connective Nervous

Levels of structural organization 4. Organ – composed of at least 2 tissue types Extremely complex functions become possible

Levels of structural organization 5. Organ system – organs that work closely with one another to accomplish a common purpose 11 organ systems

Levels of structural organization 6. Organism level – sum of all structural levels working together to promote life

Necessary Life Functions Maintaining boundaries – every living organism must have a boundary different from the inside and the outside of the body The external boundaries protect the internal body Movement or contractibility – occurs when substances such as blood, foodstuffs, and urine are propelled through internal organs

Necessary Life Functions Responsiveness – aka irritability – ability to sense changes to the environment and then respond to them Digestion – process of breaking down ingested foodstuffs to simple molecules that can be absorbed into the blood

Necessary Life Functions Metabolism – includes all chemical reactions that occur within body cells Catabolism – breaking substances down Anabolism – synthesizing more complex cellular structures from simpler substances Excretion – process of removing waste from the body

Necessary Life Functions Reproduction – responsible for producing offspring Growth – increase in the size of a body part or the organism Usually by increasing the number of cell

Survival needs 1. Nutrients – contain the chemical substances used for energy and cell building 2. Oxygen – needed for the respiratory and cardiovascular systems 3. Water – accounts for 60% to 80% of body weight Provides the environment necessary for chemical reactions and fluid base for body secretions and excretions

Survival needs 4. Normal body temperature Too low – metabolic reactions become slower and slower until they stop Too high – chemical reactions occur at such a fast rate that body proteins lose their shape and stop functioning 5. Atmospheric pressure – force that air exerts on the surface of the body

Homeostasis The ability to maintain relatively stable internal conditions even though the outside world changes continuously Our body is dynamic - Very complex The state of equilibrium varies, but always within relatively narrow limits

Homeostasis – 3 components 1. Receptor – some type of sensor that monitors the environment and responds to changes by sending information to the control center 2. Control center – determines the set point at which a variable is to be maintained, analyzes the input and determines the response

Homeostasis – 3 components 3. Effector – response of the feedback to influence the stimulus, either causing it to be depressed or stimulate it so it goes faster

Negative Feedback mechanism The output of the system shuts off the original stimulus or reduces its intensity Similar to the heating system in a house Withdrawal reflex – cut or burning Glucose levels

Positive Feedback Mechanism Results or response enhances or exaggerates the original stimulus so that the activity is accelerated Likely to race out of control so they are rarely used to promote the moment to moment well-being of the body EX: blood-clotting and labor contraction P. 13

Homeostatic Imbalance As we age, our body’s control systems become less efficient and our internal environment becomes less and less stable This increases our risk of for illness

Anatomical positions and Directional Terms Anatomical position – body is erect with feet only slightly apart and palms facing forward with the thumbs pointing away from the body

Anatomical positions and Directional Terms Directional terms – explain exactly where one body structure is in relation to another The terms are found on page 16

Regional Terms 2 divisions of the body Axial part – makes up the main axis of our body and includes the head, neck, and trunk Appendicular part – consists of the appendages that are attached to the body’s axis

Body cavities and membranes Dorsal cavity – protects the nervous system organs Cranial cavity – skull Vertebral or spinal cavity which protects the spinal cord Ventral cavity – Thoracic cavity – surrounded by the ribs and muscles of the chest Abdominopelvic cavity – includes the diaphragm and the abdominal and pelvic cavities

Homeostatic Imbalance P. 19 What organs are most damaged in a vehicle accident?

Membranes in the Ventral cavity Serous membrane – thin, double-layered membrane that covers the walls of the ventral cavity and the outer surfaces of the organs Serous fluid – fluid found in between the 2 layers of the serous membrane Parietal membrane – part of the membrane lining the cavity walls

Other body cavities 1. Oral and digestive cavities – organs?? 2. Nasal cavity – part of the respiratory system 3. Orbital cavities – house the eyes 4. Middle ear cavity 5. Synovial cavity – joint cavities that surround freely movable joints like the knee and shoulder

Abdominopelvic Regions and Quadrants