Topography of the brain

Question 1

Development of the brain- neurolation

Answer 1

Neuroectoderm cells receive inductive signals from notochord

Cells thicken to form neural plate

Lateral neural plate margins fold inwards to form neural tube

Question 2

Neural crest cells differentiate into

Answer 2

1. Neurones and glia of the sensory and autonomic nervous system
2. Cells of the adrenal gland
3. Epidermis
4. Skeletal/ connective tissue of the head

Question 3

Mantle layer becomes

Answer 3

Brain parenchyma

Question 4

Ependymal layer

Answer 4

Lines ventrciles

Question 5

Lumen becomes

Answer 5

Ventricles and central canal

Question 6

Neural tube defects

Answer 6

Anencephaly

Spina bifida

Question 7

Anencephaly

Answer 7

Failure of anterior neuropore to close

Whole of the forebrain is exposed

Fatal

1/1000 pregnancies

Question 8

Spina bifida

Answer 8

Failure of posterior neural tube to close

Gap in the spine

2/1000 pregnancies

Question 9

Expansion of cranial end to form main brain regions

Answer 9

Prosencephalon- forebrain

Mesencephalon- midbrain

Rhomencephalon- hindbrain

Question 10

Prosencephalon

Answer 10

Telencephalon- cerebral hemisphere

Optic vesicles- eyes

Diencephalon- thalamus/ hypothalamus

Question 11

Rhombencephalon

Answer 11

Metencephalon- pons/ cerebellum

Myelencephalon- medulla

Question 12

Forebrain

Answer 12

Cerebral hemispheres- telencephalon

Thalamus/ hypothalamus- diencephalon

Question 13

Brainstem

Answer 13

Midbrain and hindbrain

Contains

• cranial nerve nuclei within all three regions
• vital respiratory and CV centres
• vomiting centre
• nuclei involved with motor control, sleep
• white matter tracts

Question 14

Midbrain

Answer 14

Cerebral peduncles
- white matter tracts connecting pons with diencephalon

Superior collculus
- eye movements

Inferior colliculus
- relay nuclei

Red nuclei
- motor coordination between cortex and cerebellum

Substantial nigra

• dopaminergic neurone
• part of basal ganglia

Question 15

Hindbrain

Answer 15

Pons- metencephalon

Cerebellum- metencephalon

Medulla- myelencephalon

Question 16

Grey matter

Answer 16

Mainly neuronal cell bodies

Processing parts of the brain

Question 17

White matter

Answer 17

Mainly myelinated axons (reason why its white)

Connect regions of grey matter together

Question 18

Telencephalon

Answer 18

Comprises the cerebral hemisphere/ cerebral cortex components of the limbic system and the basal ganglia

Question 19

Cerebral hemisphere

Answer 19

Divided into lobes

• frontal
• temporal
• parietal
• occipital

Question 20

Cerebral cortex

Answer 20

Outer layer of cerebral hemisphere

Folded to form gyri and sulci

• lateral sulcus (divides temporal from parietal lobe)
• precentral gyrus (motor)
• Central sulcus (divides frontal from parietal lobe)
• postcentral gyrus (sensory)

Question 21

Corpus callosum

Answer 21

White matter tract linking cerebral hemisphere

Split into genu, body and splenium

Question 22

Deep brain structures

Answer 22

Lots of brain nuclei and white matter tracts deep to cerebral hemisphere

Interconnected to form important neural pathways including

• limbic system (emotion and memory)
• basal ganglia (posture and voluntary movement)

Question 23

Limbic system

Answer 23

Spans the telencephalon and diencephalon

Main components

• cingulate cortex
• fornix
• hypothalamus
• mammillary bodies
• amydala
• hippocampus

Question 24

Fornix

Answer 24

Semi circular white matter tract connecting the hippocampus with the mammillary bodies

Question 25

Hippocampus

Answer 25

Looks like a sea horse Sits on floor of lateral ventricle

Question 26

Basal ganglia

Answer 26

Series of interconnected nuclei at base of forebrain Corpus striatum- (letniform nuncleus and caudated nucleus) Lentiform nucleus- (putamen and globus pallidus)

Question 27

Lentiform nucleus

Answer 27

Lens shaped Sits lateral to caudate nucleus 2 parts

Question 28

Caudate nucleus

Answer 28

C shaped and sits in wall of lateral ventricle

Question 29

Diencephalon

Answer 29

Comprises the thalamus and hypothalamus

Question 30

Thalamus

Answer 30

Paired structure Relays sensory information to the cortex Involved with voluntary movement, personality and consciousness

Question 31

Hypothalamus

Answer 31

Inferior to thalamus Sits between the optic chiasm and mammillary bodies Homeostasis - coordinates ANS and endocrine responses - involved in thermoregulation, feeding, drinking, circadian rhythms - receives inputs from limbic system

Question 32

Pons

Answer 32

Relay information to the cerebellum Contains reticular formation - nuclei concerned with sleep, motor control

Question 33

Medulla oblongata

Answer 33

Contains nuclei that are important in controlling respiration and the CV system Pyramid - corticospinal tract )main voluntary pathway) Oliva - formed by olivary nuclei (motor relay to cerebellum) Cuneate tubercle and gracile tubercle - nuclei form part of ascending tract

Question 34

Cerebellum

Answer 34

Posterior to brainstem - outer gray matter - underlying white matter - two cerebellar hemispheres - three lobes - contains nuclei Connected to brainstem by cerebellar peduncles

Question 35

Main functions of cerebellum

Answer 35

Motor control - control of posture - coordinating and planning limb movements - control of ete movements

Question 36

Primary vesicles

Answer 36

Prosencephalon Mesencephalon Rhomencephalon All continuous with spinal cord

Question 37

Internal capsule

Answer 37

Forms major white matter tract Internal relative to lentiform nucleus

Question 38

External capsule

Answer 38

External relative to lentiform nucleus

Question 39

Pineal gland

Answer 39

Posterior to thalamus Produces melatonin

Question 40

Brainstem

Answer 40

Cranial nerve nuclei within all three regions Vital respiratory and cardiovascular centres Vomiting centre Nuclei involved with motor, sleep White matter tracts

Question 41

Substantial nigra

Answer 41

Domapinergic neurons (contain melanin which is black) Part of basal ganglia

Question 42

Red nuclei

Answer 42

Motor coordination- relay centre between cortex and cerebellum