Neuroanatomy Part 1

Question 1

Where is CSF made?

Answer 1

Choroid plexus in the mostly the lateral ventricles

Question 2

How much CSF is produced a day? And how much fluid is total?

Answer 2

500cc, 150cc

Question 3

Where is excess CSF reabsorbed?

Answer 3

arachnoid granulations on the top of the brain (superior sagittal sinuses)

Question 4

What is the flow of CSF?

Answer 4

Lateral ventricles -> through the foramina of Monro to the third ventricle -> cerebral aqueduct (of sylvius) -> fourth ventricle -> exits inside of brain through two lateral foramina of Luschka and one medial foramen of Magendie -> cerebral cistern (above and at the foramen magnum). Then CSF flows down the spinal cord and back up and over the brain to the arachnoid granulations -> Returned to the superior sagittal sinus and returned to the venous system

Question 5

What are the three most important spinal pathways, thier function, and name and level of decussation?

Answer 5

1. Pyramidal or lateral corticospinal tract for: Voluntary movements/limbs 2. Posterior columns or dorsal columns for: Vibration, Fine touch and Position 3. Anterolateral or spinalthalamic tract for: Gross Touch, Pain, Temperature

Question 6

What is the name and level of decussation of the lateral coricospinal tract?

Answer 6

Pyramidal decussation (cervico-medullary junction)

Question 7

What is the name and level of decussation of the posterior column-medial lemiscal pathway?

Answer 7

Internal arcuate fibers (lower medulla)

Question 8

What is the name and level of decussation of the anterolateral pathways?

Answer 8

Anterior commissure (spinal cord)

Question 9

The motor cortex homunculi is _____________ to the somatosensory cortex.

Answer 9

anterior

Question 10

Origin/Distribution of internal carotid artery

Answer 10

-Common carotid artery at superior border of thyroid cartilage -Gives branches to walls of cavernous sinus, pituitary gland, and trigeminal ganglion; provides primary supply to the brain

Question 11

Origin/Distribution of anterior cerebral artery

Answer 11

-Internal cerebral artery -Cerebral hemispheres, except for the occipital lobes

Question 12

Origin/Distribution of the anterior communicating artery

Answer 12

-Anterior carotid artery -Cerebral arterial circle (of Willis)

Question 13

Origin/Distribution of the middle cerebral artery

Answer 13

-Continuation of internal carotid artery distal to anterior cerebral artery -Most of the lateral surface of cerebral hemisphere

Question 14

Origin/Distribution of vertebral artery

Answer 14

-Subclavian artery -Cranial meninges and cerebellum

Question 15

Origin/Distribution of basilar artery

Answer 15

-Formed by union of vertebral arteries -Brainstem, cerebellum, and cerebrum

Question 16

What is this artery?

Answer 16

Posterior cerebral artery (PCA)

Question 17

Origin/Distribution of posterior communicating artery

Answer 17

-Posterior cerebral artery -Optic tract, cerebral peduncle, internal capsule, and thalamus

Question 18

The dura splits into two layers, the ___________ and _____________. They form the _______.

Answer 18

-Periosteal layer -Meningeal layer -Superior Sagittal Sinus

Question 19

The ______ _________ is the sheet hanging down between the cerebral hemispheres. Represented by letter ___?

Answer 19

falx cerebri (dura), G.

Question 20

If a patient were struck in the head with a hammer, and had a head contusion, the __________ _______ would rupture and cause a _________ ___________. On Ct you would see a cresent shape.

Answer 20

-bridging veins -subdural hematoma

Question 21

The foramina of Magendie and foramen of Luschka exit into the ________ _______ of the spinal cord.

Answer 21

central canal

Question 22

If you had an obstruction in the cerebral aqueduct what would happen?

Answer 22

The third ventricle would fill up with CSF and kill an adult patient if not treated and cause the infants head to enlarge dramatically full of CSF. Increase the pressure in the brain.

Question 23

What is the falx cerebri composed of?

Answer 23

Dura matter

Question 24

What separates the somatosensory cortex from the motor cortex?

Answer 24

Central sulci

Question 25

Which letter represents the dura layer?

Answer 25

**C**. The dura is composed of the periosteal and meningeal layers and is superficial to the arachnoid and pia later

Question 26

What layers are A and B?

Answer 26

**A**. Pia mater (on the surface of the brain) **B**. Arachnoid mater

Question 27

What location represents the Spinal epidural space?

Answer 27

**K**. Spinal epidural space (natural space occupied by fat and veins)

Question 28

What letter would represent pathological seperation of dura mater from bone, e.g., by hemorrhage? What letter repressents the dura mater?

Answer 28

**J**. Cranial extradural space **I.** Cranial Dura Mater (double layer) **L**. Spinal Dura mater (meningeal layer only)

Question 29

This is the first place the CSF travels to after being generated in the choroid plexus

Answer 29

Foramen of Monro

Question 30

Label the layers of the skull from most superficial to the pericranium

Answer 30

**S**kin Subcutaneous **C**onnective tissue Galea **A**poneurotica **L**oose areolar connective tissue **P**ericranium (periosteum)

Question 31

What tears with head contusion and a subdural hematoma?

Answer 31

Bridging veins

Question 32

What is this site? If there were a blockage in this site, what would happen in infants, in humans?

Answer 32

Obstruction of the cerebral aqueduct is the most common cause of congenital hydrocephalus in infants. In adults, this would likely be more fatal because there is no stretching of the dura.

Question 33

What nerves are located in the cavernous sinus?

Answer 33

Cavernous Sinus: III (Oculomotor), IV (Trochlear), VI (Abducent), V₁ (Opthalmic), V₂ (Maxillary) Note structures around Sphenoid sinus underneath, sella turcica with pituitary in, internal carotid and optic chiasm on top

Question 34

Label all the viens

Answer 34

A. Superficial temporal B. Supratrochlear C. Supra-orbital D. Angular E. Deep facial F. Facial G. Retromandibular

Question 35

What houses the pituitary?

Answer 35

Sella turcica

Question 36

Label the main brain centers

Question 37

Label the main arteries

Answer 37

A. Anterior cerebral B. Mid cerebral C. Internal carotid D. Posterior communicating E. Posterior cerebral F. Superior cerebellar G. Basilar H. Anterior inferior cerebellar (AICA) I. Posterior inferior cerebellar (PICA) J. Vertebral K. Anterior spinal

Question 38

What area of the brain is supplied by the anterior cerebral artery? Middle cerebral? Posterior cerebral?

Answer 38

Anterior cerebral -\> The frontal and superior poles of the cerebrum Middle cerebral -\> Temporal pole of the cerebrum Posterior cerebral -\> Occipital pole of cerebrum

Question 39

What area of the brain is supplied by the internal carotid artery? Vertebral cerebral? Basilar? Posterior cerebral? Posterior communicating?

Answer 39

**Internal carotid** -\> branches to the walls of cavernouse sinus, pituitary gland, and trigeminal ganglion; primary supply to brain **Vertebral cerebral** -\> Cranial meninges and cerebellum **Basilar** -\> Brainstem, cerebellum, and cerebrum **Posterior cerebral** -\> Inf. aspect of cerebral hemisphere and occipital lobe **Posterior communicating** -\> optic tract, cerebral peduncle, internal capsule, and thalamus