Homeostasis And The Organization Of The Human Body

Front 1

What is homeostasis?

Back 1

- greek word meaning "to stay the same"
- internal state better described as dynamic equilibrium.

Front 2

How are equilibrium conditions maintained?

Back 2

by feedback mechanisms.
TWO TYPES:
- Negative Feedback: counteracts the effects of changes (ex, thermostat)

-Positive Feedback: reinforces changes to serve a phyiological need. (ex. pregnancy)

Front 3

What is the control center of the body?
What is the Human body set point?

Back 3

The human body set point is 98.6 F. (can vary by 1 degree)

The control center of the body is the hypothalamus.

Front 4

What happens to maintain body temperature?

Back 4

1. Nerve endings act as temp. sensors and send info to hypothalamus.
2. When temp drops, hypothalamus activates effector mechanisms to raise temp.
*shivering - produce heat
*blood vessel constriction
*blood vessel dilation
*chemical signals to raise metabolic rate.

Front 5

How is the human body organized?

Back 5

cells - tissues - organs - organ systems.

Front 6

Body Cavity?

Back 6

1. Cranial (brain)
2. Thoracic (chest)
3. Abdomincal (belly)
4. Pelvic (lower digestive system)

Front 7

What are tissues?
What is the study of tissues called?
What are the four types of tissues?

Back 7

Tissues are composed of cells that are similar in structure and perform a specialized function.

The study of tissue is called histology.

1. epithelial
2.Connective
3. Muscular
4. Nervous

Front 8

Epithelial?
Functions?
characteristics?

Back 8

*epithelial cells which encase all internal and external surfraces.

6 Functions:
1. Protection
2. Absorbtion
3. Sensation
4. Secretion
5. Excretion
6. Surface Transport

Common Characteristics:
- layers are usually only a few cells thick
- tightly packed
- few blood vessels
- can regenerate

Front 9

How can the tissue be classified?

Back 9

SHAPE:
1. Squamous : flat, thin linings

2. Cuboidal: looks like cubes

3. Columnar: looks like columns

ARRANGEMENT:
1. Simple: 1 cell thick

2. Stratified: 2 or more layers

3. Psudostratified: only appears layered

4. Transitional: can stretch

Front 10

Connective Tissue
characteristics?
functions?

Back 10

Characteristics?
- diverse (many functions)
- vaired composition
- cells usually spaced well apart and embedded in a non-living matrix made up of fluid, gel, fibers, or crystals.

Functions:
1. defense (from antigens)
2. Structure
3. Isolation, Storage, Transport

Front 11

Defense (connective tissue)what are the three cell types?

Back 11

Lymphocytes
- type of white blood cell
- part of immune system

Macrophages
- surround and digest foreign particles

Mast Cells
- produce histamine to dilate blood vessels near site of injury.

Front 12

Structural (connective tissue)
three cell types?

Back 12

Fibroblasts
- stay in one place
- flat, branching, irregular shape
- secrete 4 types of protein fibers into matrix....

1. Collagen fibers
- protien collagen
-wavy and strong

2. Reticulin Fibers
- protein collagen
- fine and branching

3. Elastic Fibers
- protein elastin
- fibers branch

4. Loose
- collagen and elastin fibers
-fibroblasts

Cartilage cells:
- produce cartilage
- firm, flexible, non stretchy
- contain lacunae: chambers which hold individual cells after matrix secreted

3 types of carilage -->
1. Hyaline Cartilage: end of long bones, fine collagen fibers

2. Elastic Cartilage:
small amount of elastin
flexability

3. Fibrocartilage: great ammount of support
thick bundles of collagen absorbing shocks

Bone cells: also called supporting c.t.
produce bone.