Phys Systems And Homeostasis

Question 1

What is physiology?

Answer 1

The study of how living organisms function, including their processes and the functions of their parts

Question 2

What is anatomy?

Answer 2

The scientific description of the physical structure of organisms

Question 3

What does physiological mean?

Answer 3

Normal, healthy functioning

Question 4

What is pathology?

Answer 4

The study of disease, its causes, origins, and effect on tissues and organs

Question 5

Levels of physiological organisation

Answer 5

1. Cells
2. Tissues
3. Organs
4. Organ systems
5. Whole body
   6.reproduction

Question 6

Main Human Body Composition by weight

Answer 6

Oxygen (65%)
Carbon(18%)
Hydrogen (10%)
Nitrogen (3.4%)
Calcium (1.5%)
Phosphorus (1.2%)

Question 7

Total Body water Distribution

Answer 7

Total body volume (TBV): 60-80 litres;

Total Body Water (TBW): 40-46 litres
Intercellular fluid (ICF): 28-30 litres
Extracellular fluid (ECF): 14-15 litres (plasma: 3 litres, interstitial fluid: 11 litres)

Question 8

4 main cell types

Answer 8

1. neural cells
2. muscle cells
3. epithelial cells
4. connective tissue cells

Question 9

Neural cell examples

Answer 9

hippocampal pyramidal neuron, motor neuron.

Question 10

Muscle cell types

Answer 10

Skeletal muscle, cardiac muscle, smooth muscle

Question 11

epithelial cell arrangements

Answer 11

simple epithelium, stratified epithelium, glandular epithelium

simple epithelium:
what is it?
a single layer of cells
good for absorption, secretion, and filtration, substances can pass thru easily.

found:
simple squamous: (lining of blood vessels)
cube shaped cells: (kidney and tubules)
simple columnar: (lining of intestines)

stratified eptihelium
what is it?
a layer of multiple cells stacked on top of each other
provides protection against wear and tear.
found:
skin, mouth, oesophagus
protect from friction and damage.
stratified cuboidal and columnar: rare, found in glands like sweat glands for extra protection and. secretion.

glandular epithelium
specialised cels that make and release substances
eg: enzymes, hormones, or sweat glands.
produces and secretes things.
found:
exocrine glands: which secretes (releases) substances out of the body or into cavities, sweat glands.
endocrine glands: release hormones directly into blood (thyroid gland)

Question 12

give me examples of connective tissue cell

Answer 12

Blood cells like: neutrophils, eosinophils, basophils, monocytes, lymphocytes, platelets), Bone cells (osteocytes)

Question 13

define ‘Tissues’

Answer 13

a collection of similar cells that carry out a specific function

Question 14

define ‘Organs’

Answer 14

structures containing two or more tissues performing a particular function.

Question 15

define ‘Organ Systems’

Answer 15

two or more organs working together

Question 16

what is homeostasis?

Answer 16

maintaining a relatively constant internal environment

Question 17

what is the importance of homeostasis?

Answer 17

essential for optimal cell and organ function, loss lf homeostasis can cause diseases.

Question 18

What is negative feedback?

Answer 18

a change in a variable triggers a response that reverses the change, restoring the variable to its set point. Maintains stability.

Question 19

what is positive feedback?

Answer 19

a change in a variable thst amplifies the change, pushing the system further from the set point. Often involved in processes thst need to be completed quickly.

Question 20

what is feedforward?

Answer 20

anticipatory action that minimises disruption to set points. Limits change.

Question 21

What is a regulated variable?

Answer 21

something the body keeps in balance to stay healthy, like blood pressure, blood glucose, or body temperature.

Question 22

what is a non-regualted variable?

Answer 22

A non-regulated variable is something the body doesn’t directly control to keep in balance.

It can change depending on other factors.

For example, heart rate changes based on activity but isn’t directly kept at a fixed level like blood pressure

Question 23

what is the role of the hypothalamus in homeostasis?

Answer 23

The hypothalamus is a region in the brain that acts as a key control centre for many homeostatic processes, including temperature regulation, hunger, thirst, and hormone release.

Question 24

what is the role of the pituitary gland in homeostasis?

Answer 24

located below hypothalamus, releases hormones that regulate a wide range of bodily functions, including growth, metabolism, and reproduction.

Question 25

what are pryogens?

Answer 25

substances that cause fever. they include bacteria and cytokines released by immune cells during infection.

Question 26

how do pryogens cause fever?

Answer 26

pryogens interact with the organum vasculosum of the lamina termnalis (OVLT) IN THE BRAIN, STIMULATING THE PRODUCTION OF PROSTAGLANDIN E2 (PGE2).

PGE2 raises the body’s temperature set point, leading to fever.

Question 27

what are cytokines?

Answer 27

theyre little proteins that cells release to send signals to other cells.

Question 28

what are examples of positive feedback not involving the control centre?

Answer 28

blood clotting. The loop is driven by local chemical reactions at the site of injury rather than by a central control mechanism like the brain.

Question 29

Why is hyperkalaemia dangerous?

Answer 29

Hyperkalaemia (high potassium levels) above 6.5mM can disrupt heart function and lead to cardiac arrythmias, making it a medical emergency.

Question 30

what is feedforward control? give an example.

Answer 30

feedforward anticipates change and takes action to disruption. Eg: putting on warm clothing before going into cold weather.