Organisation Of The Human Body Lectures 1.1-1.3

Question 1

What are the levels of organisation of the body?

Answer 1

1. Chemical level- molecules composed of atoms
2. Cellular level- cells are basic unit of life
3. Tissue level
4. Organ level
5. System level
6. Organism level

Question 2

What are the 4 main types of cells?

Answer 2

-epithelial cells
-nerve cells
-muscle cells
-connective tissue cells

Question 3

What are epithelial cells?

Answer 3

-tightly attached together and line hollow organs (e.g. blood vessels or digestive organs)

Question 4

What are nerves cells specialised for?

Answer 4

-specialised for communication.
Motor neurons send signals from the brain to muscles and glands to control functions.

Question 5

What are muscle cells specialised for?

Answer 5

specialised for contraction and produce movement. Examples are: skeletal, cardiac and smooth muscle.

Question 6

What are connective tissue cells?

Answer 6

-diverse group of cells
-all provide structural strength

Question 7

Function of muscle tissue?

Answer 7

Provides movement

Question 8

Function of nervous tissue?

Answer 8

Rapid internal communication

Question 9

Function of epithelial tissue?

Answer 9

Transport, function and protection

Question 10

Function of connective tissue?

Answer 10

Supports and protects organs
Binds tissues together

Question 11

Muscle tissue:

Answer 11

All muscles are attached to bones

Question 12

What does the Gastrointestinal tract include?

Answer 12

⁃ inside is lined with epithelial tissue
⁃ Wall contains smooth muscle
⁃ Nervous tissue controls muscle contraction and gland secretion
⁃ Connective tissue binds all the above tissues together

Question 13

What is homeostasis?

Answer 13

-maintenance of a stable internal environment

Question 14

What are body cells contained in?

Answer 14

A watery internal environment where exchanges are made

Question 15

Intracellular fluid (ICF)

Answer 15

-environment in which the cells live
-two components; plasma and interstitial fluid
-examples= synovial fluid, amniotic fluid etc

Question 16

What are the factors of the internal environment that are homeostatically regulated?

Answer 16

-concentration of oxygen, carbon dioxide waste products pH, water and electrolytes
-volume and pressure
-temperature

Question 17

What are the three elements of a homeostasis control system and what are their functions?

Answer 17

-receptor: detects deviations from normal in the internal environment that need to be held within narrow limits
-control centre: integrates info with other relevant info
-effector: makes appropriate adjustments in order to restore factor to its desired value

Question 18

What is feedback? And what are the types of feedback in a homeostatic control system?

Answer 18

Feedback: refers to responses made after a change has been detected
-Negative: stimulus causes a response—> leads to a decrease of the original stimulus. Involved in maintaining homeostasis
-Positive: stimulus causes a response—-> leads to an enhancement of the original stimulus. Process is enforced until its interrupted

Question 19

What is feedforward and what is an example?

Answer 19

-used for responses that occur before a change in the stimulus occurs
Example = increased cardiac output

Question 20

Regulation of blood glucose levels by a negative feedback mechanism:

Answer 20

-main type of homeostatic control
-involves pancreatic hormones
-opposes the initial change as the output shuts off the original stimulus
-negative feedback mechanism= variable changes in the opposite direction to that of the initial change—> returns to its original ideal value or set point.

Question 21

Regulation of human body temperature by a negative feedback mechanism:

Answer 21

-involves the hypothalamus
-essential for stable cellular metabolism
-varies within the body: core vs outer shell
-varies among individuals and throughout the day
-body temp is at 37 degrees

Question 22

Positive feedback mechanisms regulating blood clotting:

Answer 22

-response enhances the original stimulus—> output is increased
-changes occur in the same direction as the initial disturbance= disturbance moves further from the original value
-blood clotting mechanisms enhance the original stimulus so that the output is increased—> end point is reached= equilibrium is restored again.
-positive feedback usually controls infrequent events that do not require continuous adjustments.

Question 23

What can a disruption in homeostasis lead to?

Answer 23

Illness and death
-pathophysiology= abnormal functioning of the body associated with disease