14.5 Coordinated Responses Flashcards
Where is the threat detected?
Autonomic nervous system
What happens straight after the threat is detected?
The hypothalamus either:
Activates the sympathetic nervous system
OR the adrenal-cortical system (by release CRF)
How does the sympathetic nervous system respond to a threat?
Either:
Sends impulses to activate glands and smooth muscles
OR activates the adrenal medulla which releases noradrenaline or adrenaline into the blood stream
How does the adrenal-cortical system respond to a threat?
Pituitary gland secretes ACTH, which triggers the adrenal cortex to release about 30 hormones into the bloodstream.
Why does the heart rate increase when the body is under stress?
To pump more oxygenated blood around the body.
Why do the pupils dilate when the body is under stress?
Take in as much light as possible for better vision.
Why do the arterioles constrict when the body is under stress?
More blood is directed to major muscle groups and muscles of ventilation.
Why does the blood glucose increase when the body is under stress?
To increase respiration- regulating in more energy.
Name three fight or flight responses (can’t be increased heart rate, pupils dilating, arterioles constricting, or blood glucose increasing).
Smooth muscles in airways relax
Non-essential systems get shut down
And it becomes difficult to focus on small tasks
Why does it become difficult to focus on small tasks when the body is under stress?
So the body can focus on the threat.
Why do the smooth muscles in airways relax when the body is under stress?
So more oxygen can get to the lungs for respiration.
Why do non-essential systems shut down when the body is under stress?
Focus resources on emergency functions.
What does adrenaline trigger in liver cells?
Glycogenolysis
Why can’t adrenaline pass through the cell membrane, and if it can’t how does it have an effect on liver cells?
It is hydrophilic
It binds to the receptors on the surface of a liver cell membrane and triggers a chain reaction inside the cell.
Describe the chain reaction triggered by adrenaline bonding to the receptors on a liver cell. (5 steps)
- Adrenaline binds to receptor
- Adenylyl cyclase is activated
- Adenylyl cyclase converts ATP to cAMP
- cAMP activates other enzymes called protein kinases
- Protein kinases activate other enzymes, one that breaks down glycogen into glucose
