Unit 1 - Intro to Physiology - (Course Notes) Important Terms and Concepts

Question 1

Physiology

Answer 1

The branch of biology that deals with the normal functions of living organisms and their parts

Question 2

Homeostasis

Answer 2

Any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival

Question 3

Acclimatization

Answer 3

The process in which an individual organism adjusts to a change in its environment WITH NO GENETIC CHANGE (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain fitness across a range of environmental conditions

Question 4

Local control

Answer 4

The effects are exerted on neighbouring cells, e.g. paracrine control of blood vessel diameter in response to low O2

Question 5

Cell membrane

Answer 5

Found in all cells and separates the interior of the cell from the outside environment, consists of a lipid bilayer that is semipermeable and regulates the transport of materials entering and exiting the cell

Question 6

Receptor

Answer 6

Usually trans-membrane proteins (or glycoproteins), usually found in plasma membrane but can be intracellular (cytosolic or nuclear)

Question 7

Gap Junctions

Answer 7

Known as direct cell-cell communication, occur via protein channels (connexons) between adjacent cells, capable of opening and closing, found in many cell types. Communicating cell–cell junction allows ions and small molecules to pass from the cytoplasm of one cell to the cytoplasm of the next. Found joining virtually all cells in solid tissues

Question 8

Anchoring Junctions

Answer 8

Connects two cells together or connects cells to the substratum or extracellular matrix. Mechanically attaches cells together along with their neighbouring cells (and their cytoskeletons) or attaches cells to the extracellular matrix

Question 9

Tight Junctions

Answer 9

Cell–cell junction that seals adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. Function as a barrier for the paracellular transport of solutes

Question 10

Connective Tissue

Answer 10

Provides structural support and barriers, has an excessive extracellular matrix (ECM) that contains proteoglycans, collagen, elastin, and fibronectin. Five types: loose, dense, adipose, blood, supporting

Question 11

Neural

Answer 11

Carry information from one part of the body to another, very little ECM. Two types: neurons, glial cells

Question 12

Autocrine

Answer 12

Chemicals that act on the cells that produces them

Question 13

Specificity

Answer 13

Only respond to a chemical signal if they have the appropriate receptor

Question 14

Organ Systems

Answer 14

10 major systems in the human body:
1. Nervous system
2. Musculoskeletal system
3. Circulatory system
4. Respiratory system
5. Immune system
6. Endocrine system
7. Reproductive system
8. Digestive system
9. Urinary system
10. Integumentary system

Question 15

Setpoint

Answer 15

Oscillation around a [……..] is the result of homeostatic control and can change with time

Question 16

Reflex Control

Answer 16

The reaction in one or more organs controlled from elsewhere in the body. Can be any long-distance path of the nervous and/or endocrine system(s)

Question 17

Positive Feedback

Answer 17

Response sends a signal which reinforces the stimulus, sending the variable further from the set point until an external signal turns the response off. NOT homeostatic. The response reinforcing the stimulus temporarily sends the system out of control (e.g. labor)

Question 18

Negative Feedback

Answer 18

Results in a change that opposes or removes the signal thus returning the variable to its original value. Allows for homeostatic control. Keeps a system near or at the set-point. Results in oscillation around the set-point (e.g. blood pressure)

Question 19

Feedforward Control

Answer 19

Anticipatory control: predicts that change is about to happen, starts the response loop, prevents change (e.g. sight, smell or thought of food)

Question 20

Epithelia

Answer 20

Protects the internal environment of the individual. Regulates the exchange of material between external and internal environment. Consists of one or more layers of cells connected to one another and to a basal lamina

Question 21

Muscle

Answer 21

3 types: skeletal, smooth, cardiac

Have the ability to contract to produce force and movement.

Question 22

Paracrine

Answer 22

Allows cells to communicate with each other by releasing signalling molecules that bind to and activate surrounding cells when a cell targets a near by cell.

Question 23

Endocrine

Answer 23

A cell targets a distant cell through the bloodstream. The signalling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites.

Question 24

Response

Answer 24

The end of the line for a signal brought to the target cell by a signaling molecule. Once the signal has gone through transduction in the target cell, it is now ready to be put into action