Lecture 20 - External anatomy of the Brain

Question 1

What do mammalian brains have more of?

Answer 1

Convolutions

Question 2

What are convolutions related to?

Answer 2

Overall size, NOT ability

Question 3

What do the convolutions do?

Answer 3

Keep neurons with similar or related functions together spatially

Question 4

What does the forebrain partake in?

Answer 4

Sensory processing, decision making, and relay to/from body

Question 5

What does the brain stem have within it?

Answer 5

Midbrain, pons, cerebellum, and medulla

Question 6

What does the brain stem have within it dealing with the CN?

Answer 6

Cranial nerve nuclei

Question 7

What does the brain stem do?

Answer 7

Conduit of function between spinal cord and forebrain

Question 8

What are the two structures of the brain?

Answer 8

Telencephalon/Cerebrum
– and –
Diencephalon/Thalamus

Question 9

What are the landmarks in the cerebrum? (basic)

Answer 9

Hemisphere (right and left)
Gyri (Ridges)
Sulci (Grooves) - cruciate
Fissures (longitudinal and transverse)

Question 10

What are the five cerebral lobes?

Answer 10

Parietal, frontal, olfactory, temporal, and occipital

Question 11

What is the corpus callosum?

Answer 11

Axonal tract that allows communication between lobes on right and left side

Question 12

What are the commissural fibers?

Answer 12

Interconnect corresponding structures between hemispheres

Question 13

What are association fibers?

Answer 13

Interconnect different areas of cortex in same hemisphere

Question 14

What are the two kinds of projection fibers?

Answer 14

Corticopetal and Corticofugal

Question 15

What is the corticopetal?

Answer 15

Fibers entering cortex

Question 16

What is the corticofugal?

Answer 16

Fibers exiting the cortex

Question 17

Where are the motor and motor planning portions of the brain generally located?

Answer 17

Frontal and parietal lobes

Question 18

Where are the primary sensory cortices found?

Answer 18

MANY PLACES

Question 19

Where is the visual cortex?

Answer 19

Occipital lobe

Question 20

Where is the somatosensory cortex?

Answer 20

Parietal lobe

Question 21

Where is the auditory cortex?

Answer 21

Temporal lobe

Question 22

What is the diencephalon?

Answer 22

Thalamic nuclei

Question 23

What are the two parts of the thalamic nuclei?

Answer 23

Thalamus and Hypothalmus

Question 24

What is the thalamus?

Answer 24

Selectively routes motor and sensory info to portions of the cortex

Question 25

What is the hypothalamus?

Answer 25

Autonomics, appetities, temperature, circadian rhythm

Question 26

What CN nuclei are contained in the midbrain?

Answer 26

CN III and IV

Question 27

What CN nuclei are contained in the pons?

Answer 27

CN V and VI

Question 28

What CN nuclei are contained in the medulla?

Answer 28

CN VII, VIII, IX, X, XI, XII

Question 29

What do you have to worry about when there is damage to the brain stem?

Answer 29

Cranial nerve function and innervation of the body

Question 30

What protects the brain?

Answer 30

Meninges

Question 31

What are the three layers of meninges?

Answer 31

Dura mater - arachnoid mater - pia mater

Question 32

What is between the skull and the dura mater?

Answer 32

Epidural space

Question 33

What is within the epidural space?

Answer 33

Fat and veins

Question 34

What is between the dura mater and the arachnoid mater?

Answer 34

Subdural space

Question 35

What is within the subdural space?

Answer 35

Very small amounts of lymphatic fluid

Question 36

What is between arachnoid space and the pia mater?

Answer 36

Subarachnoid space

Question 37

What is within the subarachnoid space?

Answer 37

Cerebrospinal fluid

Question 38

What are the three dural reflections?

Answer 38

Falx cerebi - Falx cerebelli - Tentorium cerebelli

Question 39

What are sinuses, structurally?

Answer 39

Small gaps between folds of dura and skull

Question 40

What is the function of the sinuses?

Answer 40

Receive venous blood draining from the brain

Question 41

Where does the blood from the sinuses go?

Answer 41

Vertebral and internal jugular vein

Question 42

Where are the dura folds located?

Answer 42

Cerebral hemispheres and cerebellum

Question 43

How many ventricles are there?

Answer 43

4 total - 2 lateral, third and fourth

Question 44

What is the function of the ventricles?

Answer 44

Spaces in the brain within which CSF is produced and circulates

Question 45

What are choroid plexuses?

Answer 45

Vascular tufts into ventricles that release CSF

Question 46

What is CSF made from?

Answer 46

Ultrafiltrate of blood plasma

Question 47

What is the function of CSF?

Answer 47

Protect the brain Transports nutrients Flushes away waste products Medium for diffusion of neuroendocrine and NT's

Question 48

How often is CSF produced in dogs?

Answer 48

Continuous, ~30 mL per hour

Question 49

What is the path of the CSF?

Answer 49

Choroid plexus - Subarachnoid space - Arachnoid granulation

Question 50

What are arachnoid granulations, functionally?

Answer 50

Where the CSF can enter the venous system

Question 51

What are the arachnoid granulations, structurally?

Answer 51

Outpockets from the subarachnoid space into dural venous sinus

Question 52

What two main arteries contribute to the circulus arteriosis cerebri?

Answer 52

Internal carotid aa. and vertebral aa..

Question 53

What branches in the circulus arteriosis cerebri come off the internal carotid aa.?

Answer 53

Rostral cerebral aa. Middle cerebral aa. Caudal cerebral aa.

Question 54

What branches in the circulus arteriosis cerebri come of the vertebral aa.?

Answer 54

Basilar a. Rostral cerebellar aa. Caudal cerebellar aa.

Question 55

What does the rostral cerebral aa. supply?

Answer 55

Medial portions of the cerebral hemispheres

Question 56

What does the middle cerebral aa. supply?

Answer 56

Lateral portions of the cerebral hemispheres

Question 57

What does the caudal cerebral aa. supply?

Answer 57

Posterior portions of the cerebral hemispheres and midbrain

Question 58

What does the basilar a. supply?

Answer 58

Pons

Question 59

What does the caudal cerebellar a. supply?

Answer 59

Caudal cerebellum

Question 60

What does the rostral cerebellar aa. supply?

Answer 60

Midbrain, pons, rostral cerebellum