Brain Pt. 1

Question 1

what are meninges and 3 types:

Answer 1

membranous envelopes which surround the brain and spinal cord

• dura mater
• arachnoid mater
• pia mater

Question 2

general features: dura mater

Answer 2

most superficial, DICT
- cranial and spinal dura

• cranial dura: no epidural space, 2 layers (extensions, venous sinuses)
• spinal dura: 1 layer, has epidural space (filled with fat and ct.)

Question 3

detail of cranial dura:

Answer 3

extensions:

• falx cerebri (separates cerebral hemispheres)
• falx cerebelli (hemispheres of cerebellum)
• tenrorium cerebelli (cerebrum and cerebellum)

Question 4

general features: arachnoid mater

Answer 4

middle: avascular, subdural space (btw dura/arachnoid)
- contains interstitial fluid
- arachnoid villi project into dural venus sinuses (DVS) and drain cerebral spinal fluid (CSF)

Question 5

nervous system made up of:

Answer 5

protective structures + brain and cranial nerves

Question 6

general features: pia mater

Answer 6

innermost: well vascularised, subarachnoid space (btw arachnoid/pia)
- contains CSF

Spinal Pia:
- lateral extensions (denticulate ligaments) of thickened pia, protect/anchor the spinal cord

Question 7

features and function: CSF

Answer 7

mainly water, O2, glucose, proteins, WBC

• for protection, circulation
• circulates in cavities of brain and spinal cord, and subarachnoid spaces

Question 8

where is CSF produced:

Answer 8

in choroid plexuses (networks of blood capillaries in ventricular walls)
- from ventricles (cavities, not physical) to subarachnoid space through median and 2 lateral apertures in 4th venticle

Question 9

eg. hydrocephalus

Answer 9

• when CSF is not drained properly from brain, cause pressure in babies
• push skull bones outwards

put shunt to relieve pressure

Question 10

list parts of the brain:

Answer 10

• cerebrum,
• cerebellum,
• brain stem (midbrain, pons, medulla oblongata)
• diencephalon (thalamus, hypothalamus, epithalamus)

Question 11

features: cerebrum

Answer 11

cerebral hemispheres, basal nuclei/ ganglia (nerve cell cluster)

• hemisphere: outer grey matter/ inner white matter
• folding of grey matter: gyri= folds, sulci= grooves, fissures (deep sulci)
• lateral ventricles, separated anteriorly by septum pellucidum

Question 12

list lobes:

Answer 12

frontal, parietal, temporal, occipital, insula

Question 13

sulci and gyri found in lobes:

Answer 13

• frontal: central sulcus. precentral gyrus
• parietal: postcentral gyrus
• temporal: lateral cerebral sulcus
• occipital: parieto-occipital sulcus
• insula: deep

Question 14

features: white matter

Answer 14

myelinated axons, 3 types of tracts:

• association (btw gyri in same hemisphere)
• commissural (btw hemispheres) -> corpus callosum, anterior commissure, posterior comminssure
• projection (other parts of CNS)

Question 15

function: basal ganglia (nuclei)

Answer 15

• help initiate/terminate movement, muscle tone, subconscious contractions of skeletal muscle
• globus pallidus
• putamen (gp. + put. = lentiform nucleus)
• caudate nucleus (lentiform + caudate = corpus striatum)

Question 16

features/ function: limbic system

Answer 16

structures around upper part of brain stem and corpus striatum, inner border of cerbellum, floor of diencephalon

parts:

• limbic lobe
• cingulate
• parahippocampal gyri, hippocampus, dentate gyrus, amygdala, septal nuclei, mammillary bodies of hypothalamus, anterior/medial nuclei of thalamus, olfactory bulbs, fornix

‘emotional brain’: pain, pleasure, docility, affection, anger, memory