WEEK 6 - THE SPINAL CORD

Question 1

sympathetic function

Answer 1

• prepares body for heightened activity
• exercises, excitement, emergency, embarrassment
• fight or flight

Question 2

sympathetic responses

Answer 2

• increases HR
• bronchiole dilation
• stimulates sweating and saliva
• decreased urine and digestion

Question 3

parasympathetic function

Answer 3

• stimulates abdominal visceral activity
• conserves energy
• rest and digest

Question 4

parasympathetic responses

Answer 4

• decreased HR
• bronchiole constriction
• increased saliva
• increased digestion, defecation and urine

Question 5

somatic neurons

Answer 5

• control centre PMC
• central neurons = upper motor neuron
• peripheral motor neurons = lower motor neuron
• always excitatory
• releases Ach
• target = skeletal muscles

Question 6

autonomic neurons

Answer 6

• control centre hypothalamus
• central neurons = CNS interneurons
• peripheral motor neurons preganglionic and postganglionic motor neurons
• releases Ach or noradrenalin
• excitatory or inhibitory
• target = smooth cardiac muscle or gland

Question 7

parasympathetic motor neuron

Answer 7

preganglionic neuron = long
postganglionic neuron = short
ganglia located close to target organ

Question 8

sympathetic motor neuron

Answer 8

preganglionic neuron = short
postganglionic neuron = long
ganglion located close to the spinal cord

Question 9

sympathetic pathway

Answer 9

1. Preganglionic neuron (arises from spinal cord segments T1-L2) (Cell bodies in motor nuclei of lateral grey horns)
2. Postganglionic neuron
3. Ganglia
4. Thoracic spinal cord
5. Lumbar spinal cord

Question 10

parasympathetic pathway

Answer 10

6. Preganglionic neurons (arise from opposite ends of CNS) (cell body in brainstem motor nucleus)
7. Postganglionic neuron
8. Ganglia
9. Brain stem
10. Sacral spinal cord

Question 11

adrenal medulla

Answer 11

• releases adrenalin and noradrenalin into the blood
• effects any cell bearing adrenergic receptors
• enhance and prolongs the sympathetic response

Question 12

cholinergic receptors

Answer 12

• parasympathetic
• receptors that bind Ach
• nicotinic: always excitatory (skeletal muscles)
• muscarinic: excitatory or inhibitory (all target organs)

Question 13

adrenergic receptors

Answer 13

• sympathetic
• receptors bind NA or A
• B1 – located in the heart – increases HR - excitatory
• B2 – located in airways, blood vessels, digestive tract, and urinary organs – inhibitory
• A1- located in blood vessels and all sympathetic targets – excitatory

Question 14

excitatory receptor

Answer 14

• ESPS depolarises membrane
• action potential more likely
• increases activity

Question 15

inhibitory receptor

Answer 15

• ESPS hyperpolarises cell membrane
• action potential less likely
• decreases target activity

Question 16

agonists

Answer 16

drugs mimic the action of the NT - promote normal response

Question 17

antagonists

Answer 17

drugs that bind the receptor and block the action of the NT

Question 18

acetylcholine - Ach

Answer 18

function: cognition, memory, consciousness
location: cerebral cortex, hippocampus, brainstem

Question 19

noradrenalin - NA

Answer 19

• stimulates brain reward pleasure centres
• involved in reducing stress and enhancing attention

Question 20

dopamine

Answer 20

• stimulates brain reward and pleasure centres
• high level noted with schizophrenia
• deficient in parkinsons

Question 21

serotonin

Answer 21

mood regulation, sleep, appetite, nausea, migraine headaches

Question 22

GABA

Answer 22

function: sleep/wakefulness, motor control
location: main inhibitory NT in the brain
- alcohol increases the dampening effect (impaired motor control)

Question 23

glutamate

Answer 23

function: learning and memory
located: main excitatory NT in the brain
- excessive release = excitotoxicity (Alzheimers)

Question 24

substance P

Answer 24

mediates pain transmission to the CNS

Question 25

endorphins

Answer 25

inhibits perception of pain in the CNS - natural opiates