Section 2 Part 1: General Features, Anatomy of the Ventricles, CSF and BBB

Question 1

What does the forebrain do?

Answer 1

Receive information from our sensors and send controlling signals out to motor and visceral systems

Question 2

What are the complex computations of the forebrain called?

Answer 2

Higher cognitive processes

Question 3

Within the forebrain, what is the principle structure involved in the higher cognitive processes?

Answer 3

The cerebral cortex is the principle area, but subcortical structure also play a role

Question 4

What do cognitive deficits signal?

Answer 4

Forebrain lesion, usually a cortical pathology

Question 5

What are the three subcortical nuclei that are part of the basal ganglia?

Answer 5

1- Caudate
2- Putamen
3- Globus Pallidus

**Together are known as Basal Ganglia with Substantia nigra and subthalamic nucleus

Question 6

What two subcortical nuclei compose the stratum?

Answer 6

Caudate and Putamen

Question 7

What are the subcortical nuclei involved in?

Answer 7

Motor control

Question 8

What do diseases of the basal ganglia result in?

Answer 8

a variety of motor symptoms, including difficulty initiating movement, abnormalities of muscle tone or the development of various involuntary motor movements

Question 9

What is akinesia?

Answer 9

Difficulty initiating movements

Question 10

What is rigidity?

Answer 10

Abnormalities in muscle tone

Question 11

Does the basal ganglia have a role in cognitive functions?

Answer 11

Yes

Question 12

What is the amydgala?

Answer 12

a subcortical nucleus

Question 13

What is the role of the amygdala?

Answer 13

It is onvolved in conrolling emotional behavior and is an important component of the limbic system

Question 14

What does the limbic system include?

Answer 14

1- amygdala
2- anterior portion of the cingulate gyrus
3- orbital and medial prefrontal gyri of the cerebral cortex
4- ventral parts of teh basal ganglia
5- hippocampus
6- parts of the thalamus that project into these cortical regions

Question 15

What does the limbic system interact?

Answer 15

Portions of the limbic system interact with the hypothalamus and autonomic area of the brainstem

Question 16

Where do the lateral ventricles reside?

Answer 16

They are large “C” shaped structures that reside in each hemisphere

Question 17

What does each lateral ventricle consist of?

Answer 17

Anterior horn, body, posterior horn, inferior horn

Question 18

Where does the anterior horn of the lateral ventricle lie?

Answer 18

Frontal lobe

Question 19

Where does teh body of teh lateral ventricle lie?

Answer 19

Extends across the frontal and parietal lobe

Question 20

Where does the posterior horn lie?

Answer 20

occipital lobe

Question 21

Where does the inferior lobe lie?

Answer 21

Temporal lobe

Question 22

Where is the third ventricle located?

Answer 22

The third ventricle is located at the midline (near the thalamus)

Question 23

What punctures the third ventricle?

Answer 23

Thalamic adhesion/ massa intermedia

Question 24

Do the lateral ventricles communicate with one another, if so, how?

Answer 24

No they do not

Question 25

Do the lateral ventricles interact with the third ventricle?

Answer 25

Yes they do, via the intraventricular foramen

Question 26

What is another name for the intraventricular foramen?

Answer 26

Foramen of Monro

Question 27

Where is the fourth ventricle located?

Answer 27

It is located below the cerebellum (the cerebellum forms the roof) and the pons region forms the floor the ventricle

Question 28

Does the third ventricle interact with the fourth ventricle, if so, how?

Answer 28

Yes it does, via the cerebal aqueduct

Question 29

Where doe the cerebral aqueduct lie?

Answer 29

The midbrain (under the superior and inferior colliculi

Question 30

What ventricle is the foramen of magendie an extension of?

Answer 30

The fourth ventricle, it extends caudally

Question 31

What ventricle is the foramen of luschka an extension of?

Answer 31

The fourth ventricle, they extend anteriorly

Question 32

What produces a hollow on the ventral medial surface of the interior horn?

Answer 32

The hippocampus

Question 33

What does the medial surface of the posterior horn normally abut?

Answer 33

The calcarine sulcus

Question 34

What is the tectum?

Answer 34

The superior and inferior colliculi. It is dorsal to the aqueduct

Question 35

What is below the tectum?

Answer 35

The tegument

Question 36

What is the main function of the Blood Brain Barrier (BBB)?

Answer 36

Maintains a stable environment for neurons to function effectively, protecting the CNS from severe fluctuations in ionic concentrations and circulating hormones and neurotransmitters released from other parts of the body

Question 37

Does the BBB allow for the entry of many ionic compounds to the CNS?

Answer 37

No, it tends to be exclusionary to many ionic compounds

Question 38

Where is the actual location of the BBB?

Answer 38

The capillary endothelium

Question 39

What are the specializations of the BBB/ capillary endothelium?

Answer 39

1- Tight junctions between capillary endothelial cells 2- few endocytotic vesicles for intracellular transport 3- a high number of mitochondria (indicative of high levels of oxidative metabolism)

Question 40

What can enter the brain through the BBB and how do they cross?

Answer 40

1- lipid soluable substances (O2 and CO2 gases) 2- Facultative and energy- dependent transport of specific water soluble substances ( glucose and amino acids) 3- ion channels allow particular ions to cross

Question 41

How do substances leave the brain through the BBB?

Answer 41

There is a reveres pump (intracellular transporters) within the astroglia that move lipophilic molecules of the brain into the blood

Question 42

Can whole cells migrate across a healthy BBB?

Answer 42

Yes-- especially lymphocytes and macrophages-- but they enter by opening tight junctions

Question 43

Do all regions of the brain have a BBB?

Answer 43

No, several regions do not have a BBB

Question 44

Why do some regions of the CNS not have a BBB?

Answer 44

Regions that need to sense fluctuation in the blood, because they are part of the circuitry for regulating these fluxes

Question 45

What pathologies are usually associated with a breakdown of the BBB?

Answer 45

Brain tumors, bacerial invasions, ischemia

Question 46

What is the most common cause of BBB breakdown?

Answer 46

Ischemia

Question 47

Describe the pathology of a stroke:

Answer 47

Loss of tissue oxygenation, introduction of toxins to the brain, ionic fluxes, damaged Na/ K pumps--- the latter two cause the cells to fill with water Eventually edema results and there can be an increase in intracranial pressure that can lead to coma and death.