Neuroanatomy

Question 1

What are the three layers that make up the meninges?

Answer 1

1. Dura Mater
2. Arachnoid
3. Pia Mater
   2&3 - leptomeninges - thinner than dura mater

Question 2

Falx Cerebri

Answer 2

Plough shaped fold of meningeal layer of dura.

Separates left & right cerebral hemispheres

Question 3

Involved in planned motor movements & inhibition of unwanted movements when at rest

Answer 3

Basal Nuclei

Question 4

Modifies motor activity generated by the precentral gyrus

Answer 4

Cerebellum

Question 5

Directs sensory input to the correct area of cerebral cortex

Answer 5

Thalamus

Question 6

Lies posteriorly on each cerebral hemisphere

Answer 6

Occipital lobe of cerebrum

Question 7

Cortex on the base of the cerebral hemisphere responsible for interpreting smell/olfaction

Answer 7

Rhinencephalon

Question 8

Commissural Fibres

Answer 8

Corpus Callosum

Question 9

Contains cerebrospinal fluid (CSF)

Answer 9

Subarachnoid space

Question 10

Lines the skull on the inside of the compact/cortical bone

Answer 10

Endosteal layer of dura mater

Question 11

Lies directly on the surface of the sulci and gyri of the brain

Answer 11

Pia mater

Question 12

Forms a web-like structure containing many blood vessels

Answer 12

Arachnoid mater

Question 13

Forms the deep lining of the dural venous sinuses

Answer 13

Meningeal layer of the dura mater

Question 14

Changes position during embryonic, fetal and postnatal development of the vertebral column

Answer 14

Conus Medullaris

Question 15

Describe positions of central and lateral grooves

Answer 15

Central groove - between frontal & parietal lobes

Lateral groove - between temporal & above frontal & parietal lobes

Question 16

Define & give example of Association Fibres; Commissural Fibres & Projection fibres

Answer 16

Association fibres - interconnect cortical sites within one hemisphere e.g. primary auditory cortex & secondary auditory cortex
Commissural fibres - run from one hemisphere to the other, connect functionally related structures e.g. corpus callosum - communication between left & right hemispheres
Projection fibres - pass between cerebral cortex & subcortical grey matter e.g. basal nuclei

Question 17

Describe flow of CSF:

Answer 17

CSF produced by choroid plexus (lateral ventricles) –> 3rd ventricle –> aqueduct –> 4th ventricle –> subarachnoid space –> arachnoid villi of dural venous sinus - reabsorption of CSF

Question 18

Accumulation of CSF in cranial cavity

Answer 18

Hydrocephalus

Question 19

Protective role of arterial blood supply

Answer 19

Protects brain & spinal cord against any possible changes in blood supply, blood pressure etc.

Question 20

Intracranial pressure increases:

Answer 20

blood pressure increases, volume of blood decreases - if pressure keeps rising the amount of blood supplied to the brain is insufficient

Question 21

Non-communicating vs Communicating Hydrocephalus

Answer 21

Non-communicating hydrocephalus (obstructed) - flow of CSF is blocked along 1/more passages connecting ventricles
Communicating hydrocephalus - CSF can flow between ventricles which remain open

Question 22

Blood brain barrier (BBB)

Answer 22

• Between arterial blood & brain (vascular endothelium of capillary bed in brain parenchyma)
• O2, CO2, glucose, alcohol, nicotine, heroine pass through cells
• Well developed barrier
• Non-fenestrated
• Tight junctions
• Thick basement membrane
• Astrocytes have foot processes wrap around capillaries - impermeable
• End plates become looser when we sleep - more permeable to flush out waste products

Question 23

Blood- CSF barrier

Answer 23

• Choroid epithelium (choroid plexus)
• Tight junctions & impermeable
• Active transport of NA, Cl , bicarbonate ions
• well developed barrier

Question 24

CSF - Brain barrier

Answer 24

• ependymal cells

- permeable

Question 25

Structures that lie outside of the BBB

Answer 25

Hypothalamus - sensitive to hormones
Posterior pituitary - release of hormones
Pineal gland - release of hormones
Area Postrema (floor of 4th ventricle) - chemoreceptor trigger zone - the vomition centre

Question 26

Lobes of Brain & functions

Answer 26

Frontal lobe - cognitive functioning, voluntary gross motor movement
Temporal lobe - memory processing & integration of memory with sensation, emotion, hearing & language
Parietal lobe - sensory information processing such as general sensation, taste, temperature, pain & pressure
Occipital lobe - visual processing

Question 27

Anterior & Posterior parts of corpus callosum

Answer 27

Anterior - ROSTRUM (mouth & nose)

Posterior - SPLENIUM (back of head & neck)