1. A&P: Unit 1
Body Organization

2. Anatomy Study of the structure and shape of the body
“ana-” is apart, “-tomy” is to cut
Subdivisions include
Gross Anatomy: looking at large, easily observable structures of the body
Microscopic Anatomy: looking at structures through a microscope (ex: cells and tissues)
Usually studied in dead specimens

3. Physiology Study of how the body and its parts work or function
“physio-” is nature, “-ology” is the study of
Usually studied in living subjects

4. The two are related!
Each part has a job to do to make your body work the way it’s supposed to!
The structure of organs & systems determines what functions can take place

5. 11 Organ Systems of the Body
Integumentary System
Includes: The skin
Function: Protects deeper tissue, regulates body temperature, synthesizes Vitamin D

6. 11 Organ Systems of the Body
Muscular System
Includes: Skeletal muscles, cardiac muscles, smooth muscles, and tendons
Function: contract to allow movement, maintains posture

7. 11 Organ Systems of the Body
Skeletal System
Includes: Bone, Cartilage, Ligaments, Joints
Function: Supports body, Protects certain cavities, Stores minerals

8. 11 Organ Systems of the Body
Digestive System
Includes: Mouth, Esophagus, Stomach, Small and Large Intestine, Rectum, and Liver
Function: Breaks down food to deliver nutrients to the body cells; undigested food leaves body as feces

9. 11 Organ Systems of the Body
Respiratory System
Includes: Nasal Passages, Pharynx, Larynx, Trachea, Bronchi, and Lungs
Function: Supplies blood with oxygen and removes carbon dioxide

10. 11 Organ Systems of the Body
Cardiovascular System
Includes: Heart, Blood Vessels (Veins, Arteries, and Capillaries)
Function: Carries oxygen, carbon dioxide, nutrients, hormones, wastes, etc. through the body in blood

11. 11 Organ Systems of the Body
Nervous System
Includes: Brain, Spinal Cord, Nerves, and Sensory Receptors
Function: detect and respond to internal & external changes by activating appropriate muscles and glands

12. 11 Organ Systems of the Body
Urinary System
Includes: Kidneys, Ureters, Bladder, and Urethra
Function: Eliminates nitrogenous wastes from the body, maintains body’s water and salt balance, regulates pH of the blood

13. 11 Organ Systems of the Body
Lymphatic System
Includes: Lymphatic vessels, Lymph Nodes, Spleen, Thymus, Tonsils
Functions: Picks up fluid leaked from blood vessels and returns it to blood, cleanses blood, house white blood cells (involved with immunity)

14. 11 Organ Systems of the Body
Endocrine System
Includes: Glands - including pineal, pituitary, thyroid, thymus, adrenal, pancreas, testis (males), and ovaries (females)
Function: secretion of hormones that regulate body activities (growth, reproduction, and metabolism)

15. 11 Organ Systems of the Body
Reproductive System
Males
Includes: testes, scrotum, penis, glands, duct system
Function: Produces sperm and carries to the outside of the body

16. 11 Organ Systems of the Body
Reproductive System, con’t
Females
Includes: uterus, ovaries, fallopian tubes, vagina
Function: Produces eggs, serves as locations for fertilization and development of the fetus

17. Levels of Organization
From smallest unit to largest unit:
Chemical Level: atoms and compounds
Cells: smallest unit of all living things
Tissues: similar cells with common function
There are 4 types of tissue – Epithelial, Connective, Muscle, and Nervous
Organ: composed of two or more tissue types
Organ System: organs that cooperate to accomplish a common goal
Organism: highest level of organization

18. Necessary Life Functions
Organ systems work together to promote the well-being of the entire body
Some systems have a main function that they contribute
There are 8 necessary life functions:
Maintaining Boundaries - Metabolism
Movement - Excretion
Responsiveness - Reproduction
Digestion - Growth

19. Necessary Life Functions
Maintaining Boundaries
“Insides” need to remain distinct from “Outsides”
Ex: Integumentary – skin protects internal organs from bacteria, chemicals, drying out, heat, etc.
Movement
Get from one place to another
Ex: Muscular and Skeletal – body
Ex: Cardiovascular, Digestive, & Urinary – blood, nutrients, and urine

20. Necessary Life Functions
Responsiveness (Irritability)
Ability to sense changes and react to them
Ex: Nervous system
Digestion
Break down food into molecules
Ex: Digestive System

21. Necessary Life Functions
Metabolism
Chemical reactions which occur within body cells
Breaking down complex molecules, building different larger molecules, producing energy (ATP)
MANY systems contribute, including Digestive, Respiratory, & Cardiovascular
Regulated mainly by Endocrine (hormones)

22. Necessary Life Functions
Excretion
Removing waste from the body
Ex: Digestive and Urinary
Reproduction
Production of Offspring
Ex: Reproductive, Endocrine (hormones)
Growth
Organism increase in size by increasing number of cells
Every system experiences growth

23. Survival Needs
Our body cannot continue to function if we do not have certain survival needs…
Nutrients
Needed for energy and cell building
Oxygen
Needed for chemical reactions in body
20% of air we breathe is oxygen

24. Survival Needs Water Most abundant chemical substance in the body
60 to 80% of body weight
Provides fluid base for body secretions and excretions
Body Temperature
98ºF (37ºC) ideal for body processes
If go below, metabolic reactions too slow
If go above, metabolic reactions too fast

25. Survival Needs Atmospheric Pressure
Force exerted on surface of the body by weight of air
Breathing and exchange of O2 / CO2 in lungs needs appropriate pressure

26. Homeostasis
The body’s ability to maintain relatively stable internal conditions – needed for life
“homeo-” is unchanging, “-stasis” is standing still
This is another goal that your organ systems work together to achieve

27. Homeostasis
With homeostasis, your body isn’t really “standing still”, but it’s trying to!
It’s like a tight-rope walker – you want to stay on the wire, but sometimes other forces affect you (the wind, a slippery rope, noises, etc.)
You must react to overcome the forces and re-balance yourself over the wire.
Homeostasis works the same way…
It attempts to keep an internal balance within your body.

28. Homeostasis
Communication/coordination within the body is achieved mainly by the Nervous and Endocrine Systems, but many of the systems participate in some extent
A response is triggered by some change in the norm

29. Homeostasis
Most control mechanisms are “Negative Feedback Systems” – inhibit a change
Examples include body temperature, heart rate, blood pressure, breathing rate, and blood levels of gases & nutrients

30. Homeostasis

31. Homeostasis
“Positive Feedback Systems” are rare because they actually try to push your body out of the normal balance to react to an event that has occurred
Examples include…

32. Homeostasis Birth Bleeding
Oxytocin (causes contractions) is released due to pressure on the cervix
Ends when the fetus is expelled
Bleeding
clotting yields more clotting, which is eventually stopped by stopped blood flow

33. Homeostasis