Homeostasis (M1B1)

Question 1

what do all types of human cells have in common?

Answer 1

• need O2
• deliver products of their own chemical reaction
• have the ability to reproduce and divide

Question 2

what does homeostasis mean?

Answer 2

maintenance of the internal environment constant

Question 3

body should be stable regarding?

Answer 3

• Its PH.
• Its Temperature.
• Its Volume .
• Its contents(water ,electrolytes and nutrients) to keep normal cellular functions

Question 4

how much of the human is fluid?

Answer 4

67%

Question 5

Most of this fluid is inside the cells and is called?

Answer 5

Intracellular fluid

Question 6

About one third of fluid is in the spaces outside the cells and is called?

Answer 6

Extracellular fluid

Question 7

2 types ECF are?

Answer 7

interstitial fluid 25% and intravascular fluid (plasma) 8%

Question 9

know the table on slide 9 (normal value only)

Answer 9

…

Question 10

ICF contains large amounts of?

Answer 10

-Ions: Potassium ,magnesium , and
phosphate.
-Nutrients : Proteins.

Question 11

ECF Contains large amounts of?

Answer 11

-Ions: sodium, chloride, and bicarbonate ions.
-Nutrients : such as oxygen, glucose, fatty acids, and amino acids.
-Waste products : as carbon dioxide, urea and uric
acid to be excreted

Question 12

skim through Role of different body systems in homeostasis

Answer 12

…

Question 13

Homeostasis Body Control Systems are?

Answer 13

 Nervous control
 Hormonal control
 Feedback control

Question 14

In the walls of the carotid artery at its bifurcation and in the arch of the aorta, there are many nerve receptors called?

Answer 14

• baroreceptors (stimulated by Increased arterial blood pressure)
• chemoreceptors

Question 15

baroreceptors can send nerve impulses to the brain to inhibit the?

Answer 15

vasomotor center (decreases the
sympathetic supply to the heart and blood vessels)

Question 16

chemoreceptors is stimulated by?

Answer 16

Low oxygen tension or high CO2

tension In arterial blood

Question 17

chemoreceptors nerve impulses to the brain to stimulate the?

Answer 17

Respiratory center

(which in turn send nerve impulse to
activate the respiratory muscles and increase the respiratory rate. So the O2 or CO2 tension will return to normal level.)

Question 18

Our body contains eight endocrine glands that secrete chemical substances called?

Answer 18

hormones

Question 19

The hormonal system regulates mainly the?

Answer 19

metabolic functions

Question 20

what is Feedback control system?

Answer 20

Control of certain function by the resultant effect of this function .

Question 21

types of feedback?

Answer 21

1-Negative Feedback: most common, the resultant effect of the function will
inhibit that function. maintain stability of the internal environment ex. thyroid

2-Positive Feedback: less common, the resultant effect of a function stimulates that function, It may leads to instability of the internal environment.

Question 22

Positive Feedback Can Sometimes Be Useful as?

Answer 22

1-Blood clot formation.

2-Childbirth

3-Generation of nerve signals.

Question 23

positive feedback childbirth:
When uterine contractions become strong enough for the baby’s head to be pushed through the cervix, stretching of the cervix sends nerve signals to increase the secretion of oxytocin hormone which cause more
powerful uterine contractions.

Answer 23

…

Question 24

differences between ICF and ECF?

Answer 24

ICF: has more proteins, more potassium, less sodium ions, more phosphate ions.

ECF: no protein in interstitial only plasma, less potassium, more sodium, more chloride