COM 2 physiology

Question 1

Name the visceral functions that the ANS controls

Answer 1

• Arterial pressure
  -Sweating and bidy temperature regulation
  -Gastrointestinal motility

Question 2

What is the ANS activated mainly by

Answer 2

• Centers in the spinal cord, brain stem and hypothalamus
• Higher brain areas

Question 3

What does the ANS operate through

Answer 3

Visceral reflexes

Question 4

What is the ANS divided into

Answer 4

• Sympathetic nervous systen
  -parasympathetic nervous system

Question 5

What does the sympathetic nervous system orignate from

Answer 5

Spinal cord segmenta T1 to L2

Question 6

What does the sympathetic nervous system include

Answer 6

• paravertebral sympathetic chains
  -prevertabral ganglia
• nerves exteneded from ganaglia to organs

Question 7

In the sympathetic Nervous system where does the cell body of the preganglionic neuron lie + postganglionic neuron

Answer 7

-preganglionic neuron: Cell body in intermediolateral horn of spinal cord
-postganglionic neuron : Cell body in ganglion

Question 8

What is the distribution of the sympathetic nerves based on

Answer 8

• Embryological origin of organs

Question 9

what do T1 send fibers to

Answer 9

Upward to the head

Question 10

What do T2 send fibers to

Answer 10

Neck

Question 11

What do T3-T6 send fibes to

Answer 11

Thorax

Question 12

What do T7 - T11 send fibers to

Answer 12

Abdomen

Question 13

What do T12 -L2 send fibers

Answer 13

Downwards to the legs and pelvic organs

Question 14

What do the parasympathetic fibers leave the central nervous system through

Answer 14

• Cranial nerves, 3,7,9,10
  and sacral spinal nerves S2, S3 and sometimes S1 and S4

Question 15

What do parasympathetic pathways use

Answer 15

• preganglionic and postganglionic neurons

Question 16

What is the structure of preganglionic fibers in parasympathtic fibers

Answer 16

• LONG

Question 17

In the PSN where is the postganglionic neurons located

Answer 17

• within the wall of the target organ

Question 18

What is the name for cranical nerve 3 + what does it contribute to

Answer 18

• oculomotor
• To the pupillary sphincter and ciliary muscle of they eye

Question 19

What is the name of cranial nerve VII

Answer 19

Facial nerves

Question 20

What does the cranial nerve VII (7) contribute to

Answer 20

• Lacrimal, nasal and submandibular glands

Question 21

What is the name of cranial nerve IX -9

Answer 21

Glossopharyngeal

Question 22

What does the cranial nerve IX - 9contribute to

Answer 22

• Partoid gland

Question 23

What is the name for cranial nevre X

Answer 23

Vagus

Question 24

What does the cranial nerve X, vagus contribute to

Answer 24

-Heart , lungs, esophagus, stomach, intestines

Question 25

What does the sacral nerves (Pelvic nerves) contribute to

Answer 25

- Descendign colon, rectum, bladder

Question 26

Name the neurotransmitters both sympathetic and parasympathetic systmes use

Answer 26

- Acetylcholine and norepinephrine

Question 27

What do cholinergic fibers secrete

Answer 27

Acetylcholine

Question 28

What do adrenergic fibers secrete

Answer 28

Norepinephrine and epi ephrine in the adrena medulla

Question 29

Are all preganglionic neurons cholinergic or adrenergic

Answer 29

Cholinergic

Question 30

What does ACh stimulate im both systems

Answer 30

- Sympathetic and parasympathetic postganglipnic neurons

Question 31

What are sympathetic postganglionic neurons are mostly...

Answer 31

Adrenergic

Question 32

Parasympathetic postganglionic neurons are mostly...

Answer 32

cholinergic

Question 33

Exp;ain the process starting from an action potential how neurotransmitters are released

Answer 33

Action potential → depolarization of nerve endings → increased calcium permeability → calcium entry → release of neurotransmitter (ACh or NE) from vesicles.

Question 34

Where is ACh synthesized and from what

Answer 34

in the nerve endings choline + acetyl coA =ACh via choline acetyltransferase

Question 35

What is ACh broken down by and what is it broken down into

Answer 35

- Acetylcholinesterase - into acetate and choline

Question 36

Where does norepinephrine synthesis occur

Answer 36

Axoplasm of adrenergic nerve terminals

Question 37

Explain the steps invlolved in norepinephrine synthesis

Answer 37

Key steps: Hydroxylation of Tyrosine → Forms Dopa. Decarboxylation of Dopa → Forms Dopamine. Dopamine is transported into secretory vesicles. Hydroxylation of Dopamine inside vesicles → Forms Norepinephrine (NE).

Question 38

Where does epinephrine synthesis occur

Answer 38

Adrenal medulla

Question 39

Explain the steps of epinephrine synthesis

Answer 39

same as norepinephrine + one additional step. Key steps: Hydroxylation of Tyrosine → Forms Dopa. Decarboxylation of Dopa → Forms Dopamine. Dopamine is transported into secretory vesicles. Hydroxylation of Dopamine inside vesicles → Forms Norepinephrine (NE). 5. Methylation of Norepinephrine → Forms Epinephrine (E).

Question 40

Explain the process of removal after secretion of the neurptransmitters( norepinephrine+ epinephrine)

Answer 40

Reuptake into nerve endings (50–80% of NE). Diffusion into surrounding fluids and blood. Destruction by enzymes: monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT).

Question 41

Before ACh, NE and E can stimulate an organ what must happen

Answer 41

It needs to bind to specific receptors

Question 42

What does binding of the neurotransmitter to the receptors cause

Answer 42

- A confirmational change which can : - Change membrane permeablitity to ions -Activate or inactivate an intracellular enzyme

Question 43

What may the binding of neurotransmitters do inrelation to ionchanngels

Answer 43

May: Open Na⁺ or Ca²⁺ channels → Depolarization and excitation. Open K⁺ channels → Hyperpolarization and inhibition. Allow Ca²⁺ influx to directly trigger actions,

Question 44

What is the function of the enzyme cAMP

Answer 44

Triggers various intracellular effects

Question 45

What does the response of a neurotransmitter depend on - 3/4

Answer 45

- Type of receptor protein -The Conformational chnage caused by the neurotransmitter binding -The type of effector cell and its chemical machinery

Question 46

Name the 2 major classes of adrenergic receptors

Answer 46

- Alpha receptors -Beta receptors

Question 47

Name the subtypes of the alpha receptors + what it is linked to

Answer 47

-a1+ a2 -linked to different G proteins

Question 48

Name the subtypes of the beta receptors + what does it use

Answer 48

- B1, B2, B3 -Uses a G protein signaling

Question 49

What is the effect of norepinephrine on alpha and beta receptors

Answer 49

Excites mainly alpha receptors + lesser beta receptors

Question 50

What is the effect of epinephrine on alpha and beta receptors

Answer 50

Exictes both alpha and beta receptors

Question 51

Name the 2 types of Acetylcholine receptors

Answer 51

- Muscarinic + Nicotinic receptors

Question 52

What is muscarinic receptors activated by

Answer 52

MUSCARINE

Question 53

Where are muscarinic receptors found

Answer 53

- On effector cells

Question 54

What are muscarinic receptors stimulated by

Answer 54

Postganglionic cholinergic neurons

Question 55

What is nicotinic receptors activated by

Answer 55

Nicotine

Question 56

Where is nicotinic receptors found

Answer 56

- At autonomic ganglia and neuromuscular junction

Question 57

What system has its own intramural plexus( eneteric nervous system)

Answer 57

- Gastrointestinal system

Question 58

Explain the affect of parasympathetic and sympathetic stimulation on the gastrointestinal systems

Answer 58

PARASYMPATHETIC : -Increase gut activity Sympathetic - inhibits gut activity

Question 59

What does sympathetic stimulation of adrenal medulla release

Answer 59

80%epinephrine and norepinephrine20%

Question 60

What are the effects of norepinephrine

Answer 60

- Constricts blood vessels -Increases heart activity -Inhibits gastrointestinal tract -Dilates pupils

Question 61

What are the effects of epinephrine comparedd to norepinephrine

Answer 61

- Stronger cardiac stimulation -Weaker vasoconstriction Greater metabolic effects

Question 62

What does weaker vasoconstriction result in

Answer 62

-Smaller increase in arterial pressure -Greater increases in cardiac output

Question 63

What system does adrenal medullae support

Answer 63

Sympathetic nervous system

Question 64

What does the adrenal medulla provide for the sympathetic nervous system

Answer 64

Provides direct nerve stimulation and indirect hormone mediated stimulation

Question 65

What is a low stimulation frequency needed for

Answer 65

- Full autonomic effect

Question 66

What is tone?

Answer 66

Continous basal activty of autonomic systems

Question 67

What is the function of sympathetic tone+ what can it cause

Answer 67

-Keeps the systemic arterioles constricted -Can cause vasoconstriction

Question 68

What does parasympathetic tone maintain

Answer 68

Gut motility and function

Question 69

What does cutting the vagus nerves result in

Answer 69

- Gastric and intestinal atony (loss of tine) leading to constipation

Question 70

What does cutting autonomic nevres result in

Answer 70

Loss of tone

Question 71

Does gastrointestinal tone have long or short long lasting impacts

Answer 71

- Long lasting impacts

Question 72

After a sympathtic or parasympathetic nerve is destroyed what happens to the sensitivity of the target organ

Answer 72

Target organ becomes more sensitive to injected neurotransmitters

Question 73

What is the increased sensitivity to neurotransmitters called

Answer 73

- Denervation supersensitivity

Question 74

What does the cardiovascular (baroreceptor reflex) inhibit and activate

Answer 74

- Inhibites sympathetic impulses to the heart and ACTIVATES parasympathetic impulses, lowering blood pressure

Question 75

What does the gastrointestinal reflex trigger

Answer 75

- Triggers vagal and glossopharyngeal nuclei

Question 76

What is sexual reflexes initiated by

Answer 76

- By both brain and local stimuli

Question 77

What are all the effects that happen in the fight or flight response

Answer 77

- Increases blood pressure -Increased metabolism and glucose -Increases blood clotting -Enhanced muscle strength

Question 78

What is autonomic functions controlled by

Answer 78

- Neurons in the medulla, pons and mesencephalon

Question 79

What does a transection below the medulla drop?

Answer 79

-It drops arterial pressure