neuroanatomy

Question 1

pineal gland

Answer 1

The pineal gland produces melatonin, a serotonin derived hormone which modulates sleep patterns in both circadian and seasonal cycles. The shape of the gland resembles a pine cone, hence its name.

Question 2

corpus callosum

Answer 2

orpus callosum consists of about 200 millon axons that interconnect the two hemispheres. The primary function of the corpus callosum is to integrate motor, sensory, and cognitive performances between the cerebral cortex on one side of the brain to the same region on the other side.

Question 3

layers of the meninges in order

Answer 3

dura mater arachnoid mater pia mater

Question 4

what makes up the brain stem

Answer 4

pons medulla oblongata midbrain

Question 5

posterior - vertebro-basilar artery system

Answer 5

subclavian -> vertebral artery -> basilar artery -> posterior cerebral artery superior cerebellar artery

Question 6

anterior circulation - carotid

Answer 6

common carotid - > bifurcates into internal/external carotid -> internal carotid anterior communicating artery anterior cerebral artery middle cerebral artery

Question 7

watershed zones

Answer 7

vulnerable to anoxia, watershed infarcts area where end vessels from MCA and ACA meet

Question 8

major divisions of the CNS

Answer 8

cerebrum cerebellum brainstem spinal cord

Question 9

basal ganglia

Answer 9

caudate nucleus putamen globus pallidus

Question 10

brainstem

Answer 10

Brainstem • Many fiber tracts carrying motor and sensory information travel through the brainstem; other fiber tracts begin or end within the brainstem. • Brainstem contains important groups of neurons that control equilibrium, cardiovascular activity, respiration, and other functions.

Question 11

cerebellum

Answer 11

• Consists of two large cerebellar hemispheres and a midline vermis. • Attached to the posterior brainstem by large bundles of fibers called peduncles. – Superior, middle, and inferior peduncles join the midbrain, pons, and medulla with the cerebellum. • Main function is to coordinate movements.

Question 12

thalamus

Answer 12

receives and integrates all* sensory information; important for regulation of consciousness, arousal, memory

Question 13

hypothalamus

Answer 13

Important in maintaining homeostasis, emotional expression, regulation of circadian rhythm, endocrine regulation of growth, metabolism and reproductive organs

Question 14

epithalamus

Answer 14

includes Pineal gland which helps regulate circadian rhythms and influences secretions of the pituitary gland, adrenal and parathyroid glands

Question 15

Somatosensory receptors

Answer 15

• Cutaneous receptors – Mechanoreceptors – Chemoreceptors – Thermoreceptors *nociceptors • Proprioceptors – Muscle spindle – Golgi Tendon Organ – Joint receptors

Question 16

Cutaneous innervation

Answer 16

• Cutaneous receptors respond to touch, pressure, vibration, stretch, noxious stimuli, and temperature. • Touch – Fine (discriminative) touch includes a variety of receptors – Crude (non-discriminative) touch is mediated by free endings throughout the skin.

Question 17

Muscle spindle (proprioceptors)

Answer 17

• Respond to quick and prolonged stretches of the muscle. • Important to adjust muscle tone

Question 18

Golgi tendon organs

Answer 18

• GTO respond to force generated by the muscle contraction

Question 19

joint receptors

Answer 19

• Joint receptors respond to mechanical deformation of joint capsules and ligaments.

Question 20

dorsal column/medial lemniscus pathway

Answer 20

– Discriminative touch – Conscious proprioception – Vibration • 3 neurons in line – 1st cell body in ipsilateral dorsal root ganglion – 2nd cell body in ipsilateral sensory nuclei at medulla – 3rd cell body in contra-lateral thalamus decussates caudal medulla

Question 21

pain

Answer 21

• Composed of both sensation and the emotional response to the sensation. • Nociceptors: free nerve endings that receive information about stimuli that damage or threaten to damage tissue. – Fast pain (Anterolateral/ spinothalamic pain) is the initial and immediate sharp sensation that helps us localize the injury – Slow pain (spinolimbic pain) is the dull, throbbing ache following fast pain that is not well localized that assists us with our behavioral response to injury • Sensation depends on several aspects including emotional state, cultural background etc

Question 22

anterolateral, spinothalamic tract

Answer 22

decussates at the spinal level – Fast pain – Temperature – Crude touch • 3 neurons in line – 1st cell body in ipsilateral dorsal root ganglion – 2nd cell body in ipsilateral dorsal horn – 3rd cell body in contra-lateral thalamus

Question 23

medial pain (slow)

Answer 23

• Dull, aching, throbbing pain • C fibres • Diffuse signals to several brain structures including the limbic system and brainstem • Can generate a widespread response involving the whole body, modulate the sensitivity of the receptors and other parts of the pathway • Helps us with understanding the impact, activates a decision making process and a response

Question 24

sensory contribution to movement

Answer 24

• Feedforward refers to the anticipatory use of sensory information to prepare for movement. • Feedback refers to the use of sensory information during or after movement to make corrections either to the ongoing movement or to future movements.

Question 25

Cranial Nerves

Answer 25

Question 26

sensory humunculus

Answer 26

Question 27

motor humunculus

Answer 27

Question 28

Nerve Fibres

Answer 28

Question 29

myotomes

Answer 29

Question 30

Dermatomes

Answer 30