Introduction to Anatomy & Physiology

Mrs. Yanac

Anatomy• Study of the STRUCTURE of organisms &

their relationship to each other.• “What are the structures of the body?”

Physiology

• Study of body FUNCTION.• “How do parts work?”

Relationship between A & P

• “STRUCTURE determines FUNCTION”• Anatomy & physiology are closely related as to

the function depends on how it is put together.

Levels of organization• Chemical

- Atoms & molecules• Cellular

- Basic structural & functional unit of all living things- Smallest unit of life

• Tissue - Cells with similar structure & function

• Organ - 2 or more tissue types that work together to perform 1 or more

functions• Organ systems

- A group of organs working together• Organism

- Many systems that work together to maintain life- Highest level of structural organization

Structural Organization

Necessary Life FunctionsMaintaining boundaries

– Cell membranes and integumentary system

Movement– Muscular and skeletal systems

Responsiveness– Sensing changes in the environment (nervous system)

Digestion– Breaking down food to get energy

Metabolism– All chemical reactions within the body (endocrine system)

Excretion– Removal of wastes (urinary/excretory system)

Reproduction– Ensures continuation of the species

Growth & Development– Increase in size

Human Organ Systems

1. Integumentary – skin, hair, and nails for protection and regulation

2. Skeletal – support and protection

3. Muscular – movement

4. Nervous – control system

5. Endocrine – communication within the body

6. Cardiovascular – transport and delivery (circulatory)

7. Lymphatic - body’s defense system (immune)

8. Respiratory – gas exchange

9. Digestive – breakdown of food & waste excretion

10. Urinary – removes wastes from the blood (excretory)

11. Reproductive – production of offspring

Figure 1.2a–c

Figure 1.2d–f

Figure 1.2g–i

Figure 1.2j–l

Survival Needs

• Nutrients– Contain chemicals used for energy & cell building

• Oxygen– Needed to carry out cellular respiration

• Water– 60-80% of body weight– Fluid base for the body

• Body Temperature– Needs to be maintained at 37oC (98oF)

• Atmospheric Pressure– Breathing & gas exchange depend on proper pressure

Homeostasis

• Maintaining a constant (stable) internal environment

• Depends on a constant state of– Chemical composition– Temperature– Pressure & Volume

• All body systems work together to maintain homeostasis, but it is mainly controlled by the nervous & endocrine systems.

• Internal conditions may change & vary, but always within narrow limits…equilibrium is VITAL!

Homeostatic Regulation

• Autoregulation (intrinsic)– Adjust automatically in response to environmental

change• When O2 levels decline in tissue, cells release chemicals that

dilate local blood vessels to increase rate of blood flow which provides more O2

• Extrinsic regulation– Results from activities from nervous or endocrine system

• We you set your hand on a hot stove, the heat produces a painful, localized disturbance & the nervous system orders your muscles to pull your hand away from the stove

Regulatory Mechanism

• Receptor– Sensor that is sensitive to a particular

environmental change or stimulus• Control Center– Area that receives & processes the info

• Effector– Cell or organ that responds to the commands of

the control center– Action either opposes or enhances the stimulus

Negative Feedback Mechanisms

Stimulus produces a response that OPPOSES the original stimulus (does the opposite)

Example: Temperature control• If body temp exceeds 37oC (98.6oF),

hypothalamus acts as a thermostat & heat loss is increased through enhanced blood flow to skin & increased sweating

Positive Feedback Mechanisms

Stimulus produces a response that ENHANCES or SPEEDS UP the original stimulus (domino effect)

Example: Blood Clotting• Break in blood vessel wall causes bleeding.

Damaged cells release chemicals that attract platelets to which will block the break and stop the bleeding.

http://www.google.com/url?sa=i&rct=j&q=positive+feedback+mechanism&source=images&cd=&cad=rja&uact=8&docid=0LhgIZD5pTCEUM&tbnid=K93aNKXdNtBj5M:&ved=0CAUQjRw&url=http://www.apsu.edu/thompsonj/Anatomy%20%26%20Physiology/2010/2010%20Exam%20Reviews/Exam%201%20Review/Ch01%20Regulation%20Terms.htm&ei=V_IOVKTuPJS6ggTRv4HwAQ&bvm=bv.74649129,d.eXY&psig=AFQjCNFXOf93xpZ9SkiYIVPQLoS4qEdYeg&ust=1410352051028916

Anatomical Position

• Standing, feet apart, with palms forward and thumbs facing outwards.

Directional Terms• Anterior and Posterior, which describe structures at the front (anterior) and back

(posterior) of the body. • Superior and Inferior, which describe a position above (superior) or below (inferior)

another part of the body. • Proximal and Distal, which describe a position that is closer (proximal) or further

(distal) from the trunk of the body. • Superficial and Deep, which describe structures that are closer to (superficial) or

further from (deep) the surface of the body. Sometimes profound is used synonymously with deep.

• Medial and Lateral, which describe a position that is closer to (medial) or further from (lateral) the midline of the body.

• Ventral and Dorsal, which describe structures derived from the front (ventral) and back (dorsal)

• Cranial and Caudal, which describe structures close to the top of the skull (cranial), and towards the bottom of the body (caudal).

• Occasionally, sinister for left, and dexter for right are used

Body Planes

Anatomical Landmarks

Body Cavities

VIDEOS

• CRASH COURSE: Intro to Anatomy & Physiology

• BOZEMAN SCIENCE: Anatomy & Physiology• BOZEMAN SCIENCE: Positive & Negative Feed

back Loop• DRAWN & DEFINED - Anatomical Terms• PENGUIN PROF - Anatomical Directions & Plan

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See Mr. Ford’s video series on my website under HELPFUL VIDEOS