Physio 1

Question 1

What is homeostasis?

Answer 1

Maintenance of critical physiologic parameters/functions within an optimal range (for survival).

Question 2

Describe Reflex Circuit:

Answer 2

Parameter; receptor (sensor); afferent path to integrating center; efferent path to effector; and back to parameter.

Question 3

How does the ANS regulate blood flow via sympathetic and parasympathetic system?

Answer 3

They regulate blood flow by regulating blood pressure.

Pressure regulate flow.

Question 4

Name NT and receptors in the Sympathetic Autonomic Nervous System (SANS).

Answer 4

Preganglionic - cholinergic neurotransmission (ACh & nicotinic receptor)

Postganglionic - adrenergic neurotransmission
(Norepinephrine & adrenergic receptors)

Question 5

What are the two neurons in SANS?

Answer 5

Preganglionic neurons originate in thoracic and lumbar spinal cord and target sympathetic ganglia while postganglionic neurons originate in sympathetic ganglia and target organs.

Question 6

What is the primary NT released by postganglionic neurons in SANS?

Answer 6

Norepinephrine is the primary NT released by the postganglionic neurons and it activates adrenergic receptors.

Question 7

What are the two classes of adrenergic receptors? And what are their effects?

Answer 7

Alpha: alpha 1 is excitatory and alpha 2 is inhibitory;

Beta: 1, 2, 3 are all excitatory, however, beta 2 cause muscle relaxation in smooth muscle.

All are G protein coupled receptors.

Question 8

How is SANS activated and why?

Answer 8

Hypothalamus — brain stem — preganglionic neurons in the spinal cord;

Activated in stress.

Question 9

Name NT and receptors in the PANS.

Answer 9

Pre: ACh, nicotinic receptors
Post: ACh, muscarinic receptors

Question 10

What are the muscarinic receptors?

Answer 10

M1 - increase intracellular Ca (excitatory) ;
M2 - opens K channels (inhibitory);
M3 - M1

Question 11

What are the two neurons in the PANS?

Answer 11

The preganglionic neurons originate in brain stem and sacral spinal cord and target parasympathetic ganglia in the walls of the organs that are being innervated while postganglionic neurons have very short axons and target tissues in which they originate.

Question 12

What is the primary NT in PANS?

Answer 12

ACh is. It is released by preganglionic neurons and it activates nicotinic receptors for rapid activation of postganglionic neurons.

Question 13

What is SANS and PANS effect on bronchi?

Answer 13

SANS: beta 2 - dilates (all beta are excitatory, but when on smooth muscle, it causes relaxation)

PANS: M3 - constricts (when you are relaxed you don’t have to breath too hard)

Question 14

What is SANS and PANS effect on heart?

Answer 14

SANS: beta 1, beta 2 - accelerates rate

PANS: M2, decrease heart rate

Question 15

What is allostasis?

Answer 15

Repetitive changes in a parameter (for example blood pressure) result in the system slowly shifting away from the homeostatic range to a “new normal” and the system now regulates the parameter at a new level. d

Question 16

What is physiologic reserve?

Answer 16

The reserve capacity of cells, tissues, organs and organisms that enables them to deal with increased demand - stress.

Question 17

What are the beneficial and detrimental stress?

Answer 17

acute stress is beneficial (adaptive);

chronic stress is detrimental (maladaptive)

Question 18

What is acute disease?

Answer 18

sudden/abrupt depletion of physiologic reserve demonstrated as disease symptoms at minimal activity level or even at rest.

Question 19

what is chronic disease?

Answer 19

An accelerated depletion of physiologic reserve leading to a decrease in tissue’s, organ’s or organism’s tolerance to increased demand.

Question 20

How to prevent?

Answer 20

wherever possible;

enable/help increase resilience (increase physiologic reserve)

Question 21

How to cure?

Answer 21

For some acute conditions or early chronic conditions;

permanent depletion of physiologic reserve has not yet occurred;

Question 22

What is manage?

Answer 22

chronic conditions where structural damage has already occurred (physiologic reserve already somewhat depleted)

Question 23

What is Paliate?

Answer 23

in any situation where symptoms alleviation is necessary or the only possible intervention.

Question 24

How is it possible that Norepinephrine constricts smooth muscle in the arteries of the intestines and relaxes the smooth muscle in the bronchi?

Answer 24

Norepinephrine activates the alpha 1 receptors in the intestines leading to vasoconstriction. It activates the beta 2 receptors in the bronchi that causes vasodilation.

Question 25

How is it possible that the same concentration of Epinephrine constricts arteries in the gut, but relaxes the arteries in the muscle and liver?

Answer 25

Epinephrine bind to alpha 1 in the arteries in the gut leading to vasoconstriction. It binds to beta 2 in skeletal muscle and leading to vasodilation.

Epinephrine has a higher affinity for beta 2