motor 2: extrapyramidal

Question 1

brainstem

Answer 1

btwn diencephalon and spinal cord

Question 2

3 longitudinal substructures of brainstem

Answer 2

tectum - roof (most posterior part of brainstem)
tegmentum - middle part
base is the most anterior part of the brainstem

Question 3

tectum (quadrigeminal space)

Answer 3

posterior to cerebral acquduct.
sup. and inf. medullary velum located posterior to 4thventricle
sup colliculi plays an important role in mvmt, co-ordination as well as occular reflexes

Question 4

tegmentum

Answer 4

anterior to ventricles
all ascending pathways
all brainstem nuclei except pontine
some descending pathways - extrapyramidal

Question 5

base

Answer 5

anterior to tegmentum
contains crus cerebri, base of pons, pyramids of medulla, only DESCENDING PATHWAYS (pyramidal and corticopontine)
lacks ascending pathways
contains pontine nuclei

Question 6

cerebral peduncle

Answer 6

crus cerebri + tegmentum

Question 7

midbrain

Answer 7

located rostral to the pons and caudal to diencephalon

predominantly motor centre

Question 8

motor function

Answer 8

substantia niagra, red nucleus and superior colliculi play an important role

Question 9

pons

Answer 9

divided into pontine tegmentum and basilar pons

• axons of pontine nuclei (=pontine cerebellar tract) enters the cerebellum via the middle cerebellar peduncle
• pyramidal tract is a major motor pathway that descends through the pontine base
• corticopontine pathways also descend through the midbrain & pons bases to synapse with pontine nuclei

Question 10

medulla

Answer 10

pyramidal tract descends through the pyramids (medullary base) and decussates at caudal medulla level

• relays motor and sensory pthwys
• centres for chewing and swallowing
• accomodates cardiovascular and respiratory centres

Question 11

3 major proprioceptive sensory receptors

Answer 11

fast acting and constantly elicted to adjust and maintain balance and posture during mvmt as the body is challenged by push and pull forces from the outside
muscle spindles
golgi tendon organ
joint receptors

Question 12

muscle spindles:

Answer 12

provide info about changes in muscle length. Protects muscles from over-stretching by elicting muscle stretch reflex - knee jerk
- important in stabilizing joints to maintain balance and posture

Question 13

golgi tendon organ

Answer 13

provide info about changes in muscle tension (muscle contraction) - protects muscles from high tension eg drop load if too heavy

Question 14

joint receptors

Answer 14

free nerve endings: provide info related to joint position. Present in joint capsuls and connective tissue surrounding synovial joints

Question 15

major mvmt types and organization of basic mvmt: simple pattern reflexes

Answer 15

involve spinal cord circuits only

- are automatic, unlearned and predictable relexes, no cortical input

Question 16

major mvmt types and organization of basic mvmt: complex postural adjustments

Answer 16

involve SC and surpraspinal centers (brainstem (extrapyramidal/cerebellum)
not stereotyped, but flexible and goal orientated/adaptive
- mostly coordiante their action with voluntary mvmt, hence require cortical input for coordination of their action

Question 17

major mvmt types and organization of basic mvmt: voluntary mvmts

Answer 17

involve SC, Brainstem and motor cortex (more CNS areas)

Question 18

supraspinal reflexed

Answer 18

maintain equilibrium during ongoing voluntary mvmt

- regain equilibrium after occurence of unanticipated postural pertubation

Question 19

maintain postural reflexes

Answer 19

only reticulospinal and vestibulospinal tracts