Neuroanatomy 1: Overview of Nervous System

Question 1

The nervous system can be divided into…

Answer 1

CNS: brain and spinal cord
PNS: 12 pairs of cranial nerves and 31 pairs spinal nerves and branches

Question 2

What is the first structure the brain develops from?

Answer 2

Neural tube

Question 3

What primary vesicles does the neural tube divide into? When does this occur?

Answer 3

Prosencephalon
Mesencephalon
Rhombencephalon
4 weeks

Question 4

What secondary vesicles are formed from the primary vesicles of the brain? When does this occur?

Answer 4

1st and 3rd divide at 6-8 weeks:

Prosencephalon forms telencephalon and diencephalon
Mesencephalon remains the same
Rombencephalon forms melencephalon and mylencephalon

Question 5

What structures of the brain evolve from the 5 secondary vesicles?

Answer 5

Top - toe order...
Telencephalon ---> Cerebral hemispheres
Diencephalon ---> Thalamus, hypothalamus
Mesencephalon ---> Midbrain
Melencephalon ---> Pons, cerebellum
Myelencephalon ---> Medulla oblongata

Question 6

What are the components of the brainstem?

Answer 6

Midbrain
Pons
Medulla oblongata

Question 7

What is the role of neurones, principle cells of the CNS?

Answer 7

‘Communicators’ that recieve info via synapses, integrate it and then transmit electrical impulses to another neurone or effector cell

Question 8

Most neurones are multipolar/ unipolar?

Answer 8

Multipolar

Question 9

What is the basic structure of a neurone?

Answer 9

Dendrites
One axon
Cell body

Question 10

What are the four types of glial ‘glue’ cells

Answer 10

Astrocytes
Oligodendrocytes
Microglia
Ependymal cells

Question 11

What is the most numerous cell in the CNS?

Answer 11

Glial cells

Question 12

What is the role of astrocytes? What do they look like?

Answer 12

Roles in support, maintain blood-brain barrier, environmental homeostasis
Star shape

Question 13

What is the role of oligodendrocytes? What do they look like?

Answer 13

Produce myelin in the CNS

Round nucleus which is stained

Question 14

What is the role of microglia? What do they look like?

Answer 14

Immune monitoring and antigen presentation (don’t originate from CNS)
Similar to macrophages

Question 15

What is the role of ependymal? What do they look like?

Answer 15

Line ventricles (no barrier to CSF)
Square-shaped cells that are 'epithelium like'

Question 16

What three structures give rise to the bumpy surface of the brain?

Answer 16

Gyrus (bumps)
Sulcus (grooves)
Fissures (deeper than sulcus)

Question 17

The white matter of the brain contains ___ and is found on the inside/outside of the brain which is the opposite to the spinal cord

Answer 17

Axons, glial cells, blood vessels

Inside

Question 18

The grey matter of the brain contains ___ and is found on the inside/outside of the brain which is the opposite to the spinal cord

Answer 18

Neurones, cell processes, synapses, glia, blood vessels
Outside
(H pattern in spinal cord)

Question 19

The posterior fibres in the spinal cord are involved in motor/sensory information whereas the anterior fibres convey motor/sensory information

Answer 19

Sensory from dorsal (posterior) horn

Motor from the ventral (anterior) horn

Question 20

The postcentral gyrus is associated with what type of cortex?

Answer 20

Somatosensory

Question 21

The precentral gyrus is associated with what type of cortex?

Answer 21

Somatomotor

Question 22

The lentiform nucleus can be split into…

Answer 22

Putamen

Globus pallidus

Question 23

What is the functions of the corpus callosum?

Answer 23

Connects both hemispheres of the brain

Connects brain to spinal cord

Question 24

What is the name for the touching part between the thalamus and hypothalamus?

Answer 24

Interthalamic adhesion

Question 25

Columns in the spinal cord are composed of ___ matter, whereas horns are composed of ___ matter

Answer 25

White | Grey

Question 26

Which sulci border the frontal lobe posteriorly and inferiorly respectively?

Answer 26

Central sulcus | Lateral sulcus

Question 27

Which sulci border the parietal lobe anteriorly, inferiorly and posteriorly respectively?

Answer 27

Central sulcus Lateral sulcus Parieto-occipital sulcus (to preoccipital notch)

Question 28

Which sulci border the occipital lobe anteriorly?

Answer 28

Parieto-occipital sulcus

Question 29

Which sulci border the temporal lobe superiorly, inferiorly and medially respectively?

Answer 29

Lateral sulcus Parieto-occipital sulcus (to preoccipital notch) Calcarine sulcus (to preoccipital notch)

Question 30

What is known as the fifth or 'hidden' lobe?

Answer 30

Insular lobe or insula

Question 31

What fissure extends down between the cerebral hemispheres splitting the frontal, parietal and occipital lobes?

Answer 31

Longitudinal cerebral fissure

Question 32

What are the layers of the meninges from superficial to deep?

Answer 32

1. Dura 2. Arachnoid matter (Subarachnoid space) 3. Pia matter

Question 33

Where does CSF drain to?

Answer 33

Subarachnoid space (and some to central canal of spinal cord)

Question 34

Outline the route taken by CSF

Answer 34

Lateral Vs - Interventricular foramen - 3rd V - cerebral aqueduct - 4th V - SA space

Question 35

What is known as the 3rd nervous system? Where is it located? What is it divided into?

Answer 35

Enteric nervous system In digestive system (Oesophagus - rectum) 2 wall plexuses 1. Myenteric (between SM) 2. Submucosal (submucosa)

Question 36

Outline the blood supply to the brain, splitting it into two systems

Answer 36

INTERNAL CAROTID SYSTEM Anterior cerebral arteries Middle cerebral arteries Internal carotid arteries (form MCA) VERTEBROBASILAR SYSTEM Basilar artery Vertebral arteries

Question 37

What is the Circle of Willis?

Answer 37

An arterial polygon formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk

Question 38

What territory of the brain is supplied by the ACA, MCA and PCA respectively?

Answer 38

Medial frontal lobe Lateral frontal lobe, parietal lobe and temporal lobe Mostly occipital lobe

Question 39

Outline the venous drainage of the brain

Answer 39

Blood drains into intercavernous and cavernous dural venous sinuses, then into jugular foramen and finally the internal jugular vein

Question 40

What is meant by the term 'cortical localization'?

Answer 40

Some higher functions are greater in one cerebral hemisphere - this is the dominant hemisphere

Question 41

What are the 3 types of white matter tracts in the brain?

Answer 41

Association fibres - connect cortical sites lying in same hemisphere Commissural fibres - connect one hemisphere to other Projection fibres - connect hemispheres to deeper structures including thalamus, corpus striatum, brain stem and spinal cord

Question 42

A stroke in the ACA would produce what symptoms? Be specific.

Answer 42

Contralateral weakness in the foot/leg | Contralateral sensory loss in the foot/leg

Question 43

A stroke in the MCA would produce what symptoms. Be specific

Answer 43

Contralateral weakness in the arm/hand/face | Contralateral sensory loss in the arm/hand/face