Unit 1: Intro to Anatomy

Anatomy – the structure of body parts (also called morphology)

Physiology – the function of the body parts

Homeostasis = tendency of the body to maintain a stable, balanced, internal environment. “Sameness”

Energy is required to keep the body in working order.   Where does this energy come from?

Levels of Organization

Atoms → Molecules → →Cells →Tissues → Organs → Organ Systems → Organism

Functions / Characteristics of Human Life

1. Organization  - cells, tissues, organs

2. Metabolism - reactions in the body, requires energy

3. Responsiveness - sense changes and react to them

4. Movement - change in position, motion of internal parts

5. Growth - increase in body size

6. Reproduction - passing DNA to new individuals

7. Development -  changes in the body, including differentiation.

What is differentiation?

-  the process by which a cell becomes specialized to perform a specific function

- Cells differentiate by activating and deactivating genes. 

Metabolism = all the chemical changes that occur in the body to maintain life.

Ultimately all of these processes require ENERGY

1.4 Requirements of Human Life
Oxygen - required to make ATP, cell energy

Nutrients - water, food and vitamins  

Temperature -  narrow range, body can respond to changes in temperature

Atmospheric Pressure -  pressure necessary for breathing

1.5 Homeostasis and Feedback Loops 

  - how the body makes adjustments when the environment changes  and maintains homeostasis 

-  normal range indicates where the body can function, or what is optimal    

-  the set point is the value around which the range fluctuates         

How does a negative feedback loop maintain homeostasis?

Sensors (receptors)  detect conditions within the body such as temperature, information is relayed to the brain

Set point – the normal range that an environmental parameter is to be controlled

Effectors – muscles or glands that respond to deviation from the set point.  Glands might initiate sweating to cool the body back to its set point. 

Positive feedback loops

Positive feedback loops amplify or increase the occurrence of events.

As the baby suckles on the nipple there is a nerve response into the spinal cord and up to the brain, which then stimulates the pituitary gland to produce more prolactin to produce more milk

Case Study:

When Kati arrived at the hospital and doctors began to collect information, they discovered that she weighed 128 lbs.  Oddly, when she checked in to the race, she weighed 126 lbs.

The doctor suggests that Kati might have “hyponatremia.”

In cases of water intoxication, it is extreme hyponatremia that can ultimately cause coma and death.

The doctor orders a drug that increases urination.    Kati is able to clear the extra water from her body and recovers.

Myths about drinking water.   

1)  Drinking 8 glasses a day is a must for everyone. 

2)  Drinking a glass of water before taking a bath helps lower blood pressure.

3) Being well hydrated will keep my face from getting wrinkles.

4) Drinking icy cold water will help with weight loss.

5)  Drinking a glass of water before bed prevents heart attacks. 

1.6 Anatomical Terminology

Anatomical Position                                                                   

Prone = face-down

Supine = face-up 

Superior / Inferior

Medial / Lateral            

Proximal / Distal

Dorsal / Ventral

Anterior/ Posterior  

Sagittal | Transverse | Frontal (coronal)

Superficial / Deep

General Organization of the Body

Axial Portion - head, neck, spine

Appendicular Portion
                      - arms & legs

 VISCERA = internal organs. 
                  "Visceral organs"

EVISCERATE = disembowelment

Body Cavities & Membranes

Dorsal Cavity  = back side    

Ventral Cavity = front side

Cranial Cavity =  brain

Spinal Cavity = spinal cord

Abdomen = stomach area
                (spleen, intestines)

Pelvic = lower abdomen
        (bladder, reproductive organs)

Abdominopelvic = abdomen + pelvic

DIAPHRAGM:  Separates the thoracic and pelvic region

MEMBRANES

Serous Membrane = two layers, covers organs

Outer layer = parietal

Inner layer = visceral (lines the organs)

Serous fluid – lubricating fluid

A seroma is a pocket of clear serous fluid that sometimes develops in the body after surgery. This fluid has seeped out of ruptured small blood vessels and fluid produced by the injured and dying cells.

Other Membranes

Pleura = lungs

Pericardium = heart

Peritoneum = organs (abdominopelvic region)

Lungs:

Visceral Pleura
Parietal Pleura

Heart

Visceral Pericardium
Parietal Pericardium

Intestines

Visceral Peritoneum
Parietal Peritoneum

Organ Systems

1. Integumentary

2. Skeletal

3. Muscular

4. Nervous

5. Endocrine

6. Digestive 

7. Circulatory 

8. Lymphatic

9. Urinary 

10. Reproductive

11. Respiratory