Anatomy & Physiology Anatomy – studies the structure of body parts and their relationship to one another Physiology – function of the body’s structural.

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