Lecture 3: The Brain

Question 1

Describe the dura mater

Answer 1

Strong, dense, fibrous membrane continuous with dura mater of the spinal cord
Has 2 layers: endosteal and meningeal layers
Endosteal= periosteum covering inner surface of calvaria. Does not extend through foramen magnum

Question 2

Dural septae

Answer 2

The dura mater also gives way to another support and stabilisation consisting of the four cranial dural septa.
-Falx cerebri is the largest of the 4. It divides the brain into left and right hemispheres
-tentorium cerebelli- separates the occipital lobe and temporal lobe
-Falx cerebelli- divides cerebellum into r and l hemispheres
-diaphragma sellae
Falx, tent, falx

Question 3

What is dural innervation?

Answer 3

Only meningeal layer that is innervated by sensory fibres
Richly innervated by meningeal sensory branches from trigeminal nerve, vagus nerve and upper cervical nerves.
They are stretch sensitive => headache

Question 4

How is the dura mater innervated?

Answer 4

Branches of the trigeminal nerve

Question 5

Describe the vasculature of the dura

Answer 5

Arteries of the dura supply more blood to the calvaria (ie bones of skull, ie parietal, temporal etc) than to the dura.
Middle meningeal artery (branch of maxillary)
Middle meningeal veins drain into pterygoid venous plexus

Question 6

Dural blood supply

Answer 6

Internal carotid artery
Maxillary artery 
Ascending pharyngeal artery 
Occipital artery 
Vertebral artery 
Middle meningeal arty 
Venous drainage => meningeal veins lateral to arteries

Question 7

Dural venous sinuses

Where are they located?

Answer 7

Between periosteum and meningeal layers of dura. No valves.

-contains blood from superficial brain veins

Question 8

Name some of the main dural venous sinuses

Slide 13

Answer 8

Study it bitch

Question 9

What is the thing that connects both hemispheres together?

Answer 9

Corpus callosum

Question 10

Describe the pia mater

Answer 10

Pa mat is extremely thin but highly vascularised. It sits very closely to gyri of brain and descends into sulci

Question 11

What the fark is a leptomlenix?

Answer 11

= arachnoid mater + pia mater
Indicated by arachnoid trabeculae passing between arachnoid and pia layers.
Arachnoid is avascular and NOT attached to dura, it is held against dura by CSF pressure.

Question 12

Label each ventricle of the brain

Slide ?

Answer 12

Hhhougviyfcut

Question 13

Ventricles
What is a choroid plexus and what does it do?
What does CSF do?
Where is CSF produced?

Answer 13

Ventricles lined with ependymal cells forming the choroid plexuses that produces and secrete cerebrospinal fluid.
CSF removes waste products associated with neuronal activity and gives brain buoyancy to protect it from damage.
CSF is produced it him lateral, third and fourth ventricles

Question 14

Arterial blood supply of brain

Answer 14

High energy use, no substrate (glucose) stored and can’t metabolise with ought oxygen. Need constant supply of oxygenated blood containing glucose.
Slide 26 be able to label it

Question 15

What vessels exist Cerebral arterial circle

Answer 15

Anterior communication artery 
Anterior cerebral arteries 
Internal carotid arteries 
Posterior communicating arteries 
Posterior cerebral arteries 
Slide 27

Question 16

Arteries of cerebrum

What are the principle arteries?

Answer 16

Anterior cerebral artery (branch of internal carotid artery)
Middle cerebral artery (branch of internal carotid) = largest branch, supplies most of the lateral surface of the cerebra hemispheres.

Question 17

What is the cause/ effect of aschaemic stroke

Answer 17

Result of impaired cerebral blood flow
Rapid cell death
Brain doesn’t store glucose and is incapable of anaerobic metabolism

Question 18

What is a chiasm?

Answer 18

An anatomical intersection or decussation

Question 19

What is a decussation?

Answer 19

The action of crossing in the form of an X, especially a tract of nerve fibres crossing contra lateral (opposite) side of the CNS

Question 20

What is a ganglion?

Answer 20

A mass of tissue containing cell bodies of neurons usually located outside of CNS and form an enlargement upon a nerve.

Question 21

What is a commissure?

Answer 21

Connecting band of nerve tissue between two anatomical structures

Question 22

What are fasciculus?

Answer 22

Bundles of nerve fibres that follow the same courses but do not necessarily have same functional connections

Question 23

What is a tract?

Answer 23

Bundle of nerve fibres having a common origin, termination and function

Question 24

What are the derivatives of the Forebrain (prosencephalon)

Answer 24

Telencephalon (cerebral cortex, white matter and basal ganglia)
Diencephalon (epithalamus (pineal gland), dorsal thalamus, subthalamus, hypothalamus)

Question 25

What is the name for the elevated ridges, shallow groves, and deep groves. What is the covering that surrounds it all

Answer 25

Elevated ridges = gyri
Shallow grooves= sulci
Deep groves= fissures
All covered by meninges (pia mater)

Question 26

What is the role or the hippocampus:

Answer 26

key role in memory and learning

Question 27

What is the
Fornix
Corpus callosum
Septum pellucidum

Answer 27

Fornix= tract connecting hippocampus (part of limbic system, consolidates info from short term mem to long term) to mammillary bodies (pair of small round bodies under brain, which is part of diencephalon form part of the limbic system.)
Corpus callosum= commissure between cerebral hemispheres
Septum pellucidum stretches between the two to form medial wall of ventricles.

Question 28

What are Amygdala

Answer 28

Non basal ganglia : grey matter nuclei
Located inferior to putamen and anterior to tail of the caudate nucleus
Emotional amplifier
Stimulation of amygdala= rage, fear, rest, relaxation. Dependent on prior mood

Question 29

Label cortical areas

Answer 29

Slide ?

Question 30

Neurulation
What does the neural tube become
What does the neural crest become

Answer 30

Brain and spinal cord

Neural crest becomes shwann cells that myelinate nerves of the PNS and peripheral ganglia.

Question 31

Memorise table of slide 45

Answer 31

Do it

Question 32

Know the function of different areas of the brain.

Slide 58

Answer 32

Ya

Question 33

What is the function of the thalamus?

Answer 33

Sorts and edits all pre cortical input from all sensory systems except olfactory system. Then conveys information to the cerebral cortex

Question 34

What is the function of the hypothalamus

Answer 34

Command centre for all autonomic functions in the body

Mammillary bodies activate sympathetic nervous system when stimulated

Question 35

Function of the mammillary bodies

Answer 35

Receive input from hippocampal formation via fornix

-projects to anterior nucleus of thalamus

Question 36

Function of pituitary gland

Answer 36

• connects to hypothalamus by the infundibulum
• anterior lobe –> hormone producing
• posterior lobe–> hormone releasing
• hypophyseal portal venous system carries hormones into circulation

Question 37

Function or pineal gland

Answer 37

Lies between the superior colliculi on posterior wall of third ventricle.

• produces malatonin–> hormone that regulated circadian rhythms
• commonly calcified in middle age

Question 38

What is the function of the lateral geniculate body

You wish to a geni for vision.

Answer 38

Relays visual impulses from optic tract to primary visual cortex

Question 39

Function of medial geniculate body

Answer 39

Relays auditory impulses from inferior colliculus to primary auditory cortex

Question 40

Be able to spot the ventricles in different angles inside the brain using app

Answer 40

Her diagrams are shit

Question 41

Venous drainage.

Answer 41

Venous drainage by cerebral and cerebellar veins that drain to dural venous sinuses