nerve cells & connections 5-8

Question 1

Cortical control of movement: what does it cover

Answer 1

reflexes vs. rhythmic movements vs. voluntary movements

Question 2

what does the premotor cortex do

Answer 2

Decides if a movement should be made

Question 3

what maps the motor homunculus

Answer 3

Electrical stimulation of primary motor cortex in conscious patients maps the motor homunculus

Question 4

describe where Neurons of the motor cortex connected to

Answer 4

directly to motor neurons, mainly on the contralateral side of the spinal cord, via the corticospinal (= pyramidal) tract

Question 5

what is the function of basal ganglia

Answer 5

Plans the details of how to make a specific movement

Question 6

what does the basal ganglia consist of

Answer 6

Consists of the striatum (caudate + putamen), globus pallidus and substantia
nigra

Question 7

basal ganglia: how do the Striatum and substantia nigra communicate

Answer 7

Striatum and substantia nigra talk to each other via the nigrostriatal and
striatonigral pathway

Question 8

what section of the brain does Parkinson’s have to do with

Answer 8

basal ganglia, loss of motion

Question 9

basal ganglia: how is Parkinson’s characterised

Answer 9

by a resting tremor, rigid paralysis, and difficulty in initiating movements

Question 10

what do post mortem studies on patients with Parkinson’s disease show

Answer 10

Post-mortem studies on patients with Parkinson’s disease show that they have
lost over 80% of their nigrostriatal fibres

Question 11

dopamine: what pathway is dopaminergic

Answer 11

the nigrostriatal pathway

Question 12

dopamine: what is associated with schizophrenia

Answer 12

Over-activity of dopaminergic neurons (in another region of the brain) is associated with schizophrenia

Question 13

dopamine: what does reserpine do

Answer 13

Reserpine, which was used to deplete dopamine, caused Parkinson’s symptoms in some schizophrenic patients

Question 14

Dopamine: what is used to treat Parkinson’s

Answer 14

L-DOPA (levodopa)

it is a precursor of dopamine, which can cross the blood-brain barrier and
then gets converted into dopamine

Question 15

function of the cerebellum

Answer 15

Coordinates timing and force of movements

Question 16

what does electrical stimulation do to the cerebellum

Answer 16

does not evoke sensation or movement

Question 17

what does damage to the cerebellum do

Answer 17

damage to the cerebellum does cause impairment of movement

Question 18

where do inputs to the cerebellum come from

Answer 18

Sensory information from proprioceptors and vestibular apparatus
Motor cortex (via the thalamus)

Question 19

where do Outputs from the cerebellum go to and via which pathway

Answer 19

Spinal cord (via the rubrospinal tract)
* Motor cortex (via the thalamus)

Question 20

what do cases of damage to the cerebellum suggest

Answer 20

it fine tunes movements initiated by the
cerebral cortex

Question 21

brain stem and spinal cord: name the simple reflexes it is responsible for

Answer 21

• Muscle spindle (stretch) reflex
• Golgi tendon organ reflex
• Flexion (withdrawal) reflex and crossed extensor reflex

Question 22

Brainstem and spinal cord: what does the brain stem do

Answer 22

the site of integration of postural reflexes

Question 23

Brainstem and spinal cord: what does spinal cord generate

Answer 23

generates locomotor rhythms but does not act independently

Question 24

Brainstem and spinal cord: where does the sensory information go

Answer 24

Sensory information is also sent up the spinal cord to higher centre

Question 25

Brainstem and spinal cord: what does spinal cord transection show

Answer 25

that reflexes are modulated by descending inputs from higher centres

Question 26

what is the function of the central pattern generators and where is it located

Answer 26

Generates locomotor rhythms, in the spinal cord

Question 27

how does this all fit together: describe the process of voluntary movement

Answer 27

1.Voluntary movement is planned in premotor cortex *2. Primary motor cortex selects appropriate motor command 3. Crude command sent to basal ganglia 4. It organises and refines the crude programme and relays it back to the motor cortex 5. Motor cortex (via corticospinal tract) activates α and γ motor neurons 6. During movement, information from periphery continually keeps cerebellum updated to correct errors 6. Spinal and brainstem reflexes play a role throughout

Question 28

compare and contrast the muscles that work within the somatic and autonomic nervous system

Question 29

difference between autonomic somatic nervous systems

Answer 29

A: has Ganglion, preganglionic fibre, post ganglionic fibre

Question 30

what's the difference between the preganglionic fibre and the post ganglionic fibre

Question 31

what are the 3 types of nervous system in autonomic nervous system

Answer 31

sympathetic/ parasympathetic, enteric nervous system

Question 32

Autonomic vs. somatic nervous systems: types of receptors, influence on targets, junction type ?

Answer 32

somatic nervous systems - Specialised NMJ * Ionotropic receptors * Always excites target Autonomic nervous system * Less specialised junction * Metabotropic receptors * May excite or inhibit target

Question 33

what are the two divisions of PNS

Answer 33

afferent + efferent divisions

Question 34

which division is the autonomic and somatic nervous system in the PNS

Answer 34

efferent division

Question 35

autonomic nervous system function

Answer 35

sympathetic and parasympathetic

Question 36

where is sympathetic outflow from

Answer 36

thoracic (T1-12) and lumbar (L1-2) regions

Question 37

where is parasympathetic outflow from

Answer 37

from cranial (III, VII, IX, X) and sacral (S2-4) regions

Question 38

where do the sympathetic ganglia lie close to

Answer 38

lie close to spinal cord in the sympathetic chain (paravertebral ganglia), or in collateral (prevertebral) ganglia

Question 39

where do the parasympathetic ganglia lie in relations to target

Answer 39

close to or within the target

Question 40

name the autonomic transmitters

Answer 40

Ach and noradrenaline

Question 41

what receptors do autonomic transmitter : Ach act on

Answer 41

Acts on cholinergic receptors * Nicotinic receptors * Muscarinic receptors

Question 42

what receptors do autonomic transmitter : Noradrenaline act on

Answer 42

Acts on adrenergic receptors * α receptors * β receptors

Question 43

what does the Sympathetic and parasympathetic preganglionic fibres release

Answer 43

acetylcholine which acts on nicotinic cholinergic receptors

Question 44

what does parasympathetic postganglionic fibres release and what receptors do they act on

Answer 44

acetylcholine which acts on muscarinic cholinergic receptor

Question 45

what does sympathetic postganglionic fibres release and what receptors do they act on

Answer 45

release noradrenaline or adrenaline which acts on α or β adrenergic receptors

Question 46

what is a Sympathetic cholinergic fibres and what do they innervate innervate

Answer 46

postganglionic fibre and innervate sweat gland

Question 47

what receptors do Ach rely on

Answer 47

nicotinic and muscarinic receptors

Question 48

which transmitters do postganglionic fibres of peptides use

Answer 48

use non-adrenergic non-cholinergic (NANC) transmitters sometimes co-released with the orthodox transmitter

Question 49

describe the difference between the effects if radial and sphincter muscles of the eye

Answer 49

R: sympathetic, contract, pupil larger, activated by alpha receptor S: parasympathetic, contracts, pupil smaller, activated by muscarinic receptors

Question 50

describe the difference between the effects if ciliary muscles of the eye

Answer 50

S:relaxes, focus on far away, activated by beta 2 P:contract, focus up on close, activated by muscarinic receptors

Question 51

do autonomic reflexes have a higher control

Answer 51

yes they can be learned reflexes

Question 52

can autonomic reflexes be spinal reflexes and what does that mean

Answer 52

yes for example urination in babies

Question 53

function of baroreceptors

Answer 53

detect changed in blood pressure

Question 54

what does the central control coordinate

Answer 54

a sympathetic and parasympathetic outflow to vary heart rate, strength of contraction, and constriction of blood vessels accordingly