Neuroanatomy 2

Question 1

• What % of body weight does the brain account for?
• The brain receives about (…) of the cardiac output and (…) of the oxygen consumed by the body at rest
• The blood supply to the brain is from the (…) and (…) arteries

Answer 1

• 2.5%
• 1/6th; 1/5th
• internal carotid and vertebral arteries

Question 2

What are the different parts of the internal carotid arteries?

Answer 2

1. cervical part
2. petrous part
3. cavernous part
4. cerebral part

Question 3

• What part of the internal carotid artery ascends to the entrance of the carotid canal in the petrous temporal bone?
• What part of the internal carotid turns horizontally and medially in the carotid canal to emerge superior to the foramen lacerum and enters the cranial cavity?
• What part of the internal carotid runs on the lateral side of the sphenoid in the carotid groove as it traverses the cavernous sinus?
• What part of the internal carotid makes a 180-degree turn to join the cerebral arterial circle, ends in the circle of willis as terminal branches anterior and middle cerebral arteries?

Answer 3

• cervical part
• petrous part
• cavernous part
• cerebral part

Question 4

What is the passage of the vertebral arteries?

Answer 4

• begin in root of neck
• pass through transverse foramina of first 6 cervical vertebra
• perforate dura and arachnoid to pass through foramen magnum

Question 5

• The intracranial parts of the vertebral arteries unite at the caudal border of the pons to form (…)
• This artery runs through the (…) to the superior border of the pons where it ends by dividing into two (…)
• Vertebrobasilar circulation is known as (…)
• People can get very (…) if there is a vertebrobasilar issue
• What do the vertebral arteries supply?

Answer 5

• basilar artery
• pontocerebellar cistern
• posterior cerebral arteries
• posterior circulation
• dizzy
• cranial meninges and cerebellum

Question 6

Most cerebral aneurysms occur where?

Answer 6

circle of willis

Question 7

• What is the basilar artery formed by?
• What does it supply?
• How does it terminate?
• What branches does it give off?

Answer 7

• union of vertebral arteries
• brainstem, cerebellum, and cerebrum
• dividing into 2 posterior cerebral arteries
  branches:
• superior cerebellar artery
• pontine arteries
• anterior inferior cerebellar arteries

Question 8

What branches come off the vertebral arteries?

Answer 8

• anterior spinal a
• posterior inferior cerebellar arteries

Question 9

• What does the anterior cerebral arteries supply?
• What does the middle cerebral arteries supply?
• What does the posterior cerebral arteries supply?

Answer 9

• most of medial and superior surfaces of brain and frontal pole
• lateral surface of brain and temporal pole (involves most of the brain tissue)
• inferior surface of brain and occipital pole

Question 10

A stroke involving (…) will be most detrimental? (anterior, middle, posterior cerebral aa)

Answer 10

middle cerebral aa

Question 11

What supplies the medial and superior surface of cerebral hemispheres but not the occipital and temporal lobes (top of head/scalp area)?

Answer 11

anterior cerebral artery

Question 12

What supplies the medial surface of the occipital and temporal lobes?

Answer 12

posterior cerebral artery

Question 13

What supplies most of the lateral surface of the cerebral hemispheres including the motor cortex?

Answer 13

middle cerebral artery

Question 14

The middle cerebral artery controls a lot of the homunculi and will affect more of the (…) vs the (…)

Answer 14

upper extremities vs the lower extremities

Question 15

What are the 4 regions of the middle cerebral artery?

Answer 15

• M1: sphenoidal
• M2: insular
• M3: opercular
• M4: cortical

Question 16

What is the origin of these arteries:
- internal carotid
- anterior cerebral
- anterior communicating
- middle cerebral
- vertebral
- basilar
- posterior cerebral
- posterior communicating

Answer 16

• internal carotid: common carotid
• anterior cerebral: internal carotid
• anterior communicating: anterior cerebral a
• middle cerebral: continuation of internal carotid a
• vertebral: subclavian
• basilar: union of vertebral aa
• posterior cerebral: basilar a
• posterior communicating: posterior cerebral a

Question 17

What is the distribution of these arteries?
- internal carotid
- anterior cerebral
- anterior communicating
- middle cerebral
- vertebral
- basilar
- posterior cerebral
- posterior communicating

Answer 17

• internal carotid: cavernous sinus, pituitary gland, trigeminal ganglion, brain (anterior circulation)
• anterior cerebral: cerebral hemispheres, except occipital and temporal
• anterior communicating: circle of willis
• middle cerebral: lateral surface of cerebral hemispheres
• vertebral: cranial meninges and cerebellum
• basilar: brainstem, cerebellum, cerebrum
• posterior cerebral: inferior cerebral hemisphere and occipital lobe
• posterior communicating: optic tract, cerebral peduncle, internal capsule, thalamus

Question 18

Label

Answer 18

1. anterior cerebral artery
2. middle cerebral artery
3. posterior cerebral artery
4. basilar artery
5. vertebral artery
6. internal carotid artery

Question 19

Label

Answer 19

1. anterior cerebral artery
2. posterior cerebral artery (3)
3. basilar artery (4)
4. vertebral artery (5)
5. internal carotid artery (6)

Question 20

• The cerebral arterial circle (of Willis) is an important anastomosis between (…) arteries: (…) that supply the brain
• What are the names of the arteries that this circle if formed by?

Answer 20

• 4 arteries; 2 vertebral and 2 internal carotid aa
  formed by:
• posterior cerebral
• posterior communicating
• internal carotid
• anterior cerebral
• anterior communicating

Question 21

In approximately one in three people, one (…) is a major branch of the internal carotid artery

Answer 21

posterior cerebral artery

Question 22

What is the major reflex center and conduction pathway between the body and the brain, is a cylindrical structure that is slightly flattened anteriorly and posteriorly?

Answer 22

the spinal cord

Question 23

What is the spinal cord protected by?

Answer 23

• vertebrae and their associated ligaments and muscles
• spinal meninges
• CSF

Question 24

• What does the spinal cord begin as?
• The spinal cord, spinal meninges, spinal nerve roots, and neurovascular structures that supply them are in the (…)

Answer 24

• begins as a continuation of the medulla oblongata (caudal part of brainstem)
• vertebral canal

Question 25

- In a newborn, the inferior end of the spinal cord is found between (...) - In adults, the spinal cord usually ends between (...), however, its tapering end, the (...), may terminate as high as (...) or as low as (...)

Answer 25

- L2 and L3 - L1 and L2 - conus medullaris - T12 - L3

Question 26

Where is the epidural space located?

Answer 26

- between outer skin and dural space

Question 27

- What regions of the spinal cord have a slightly larger diameter? - Why is this?

Answer 27

- cervical and lumbar regions - increased numbers of neurons and axons in these regions for innervation of muscles in the upper and lower limbs

Question 28

- What is the tapered end of the spinal cord? - From the conus, the nerve rootlets course to their respective levels and form a bundle called the (...) - The spinal cord is anchored inferiorly by the (...) which is attached to the coccyx

Answer 28

- conus medullaris - cauda equina - terminal filum

Question 29

The terminal filum is a (...) that picks up a layer of arachnoid and dura mater after passing through the dural sac (at L2) and before attaching to the coccyx

Answer 29

pial extension

Question 30

- The cervical enlargement of the spinal cord extends from (...) to (...) - Most of the (...) arising from it form the brachial plexus of nerves, which innervates the upper limbs

Answer 30

- C4 to T1 - anterior rami of the spinal nerves

Question 31

- The lumbosacral enlargement of the spinal cord extends from (...) to (...) - The (...) arising from it contribute to the lumbar sacral plexuses of nerves, which innervates the lower limbs

Answer 31

- L1 to S3 - anterior rami of the spinal nerves

Question 32

How many spinal nerves are there? What are they divided into?

Answer 32

- 31 pairs (62 total) - 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 33

Motor neurons are found (...) the cord; sensory neurons are found (...) the cord

Answer 33

- inside - outside

Question 34

How many cervical spinal nerves are there? Where is the first one located?

Answer 34

- 8 - spinal nerve 1 is located above C1

Question 35

- C1 - C7 spinal nerves exit (...) to the vertebra of same name/number - C8 spinal nerve nerve exits (...) to C7 vertebra - All subsequent spinal nerves exit (...) to the vertebra of same name and number

Answer 35

- superior - inferior - inferior

Question 36

What is the spinal cord suspended by?

Answer 36

- filum terminale - right and left sawtooth denticulate ligaments

Question 37

What ligaments consist of a fibrous sheet of pia mater extending midway between the posterior and anterior nerve roots?

Answer 37

denticulate ligaments

Question 38

- The superior processes of the right and left denticulate ligament attach to the (...) immediately superior to the (...). - The inferior process extends from the (...) passing between the (...) nerve roots

Answer 38

- cranial dura mater - foramen magnum - conus medullaris - T12 and the L1

Question 39

- The (...) of the spinal nerves contain afferent (sensory) fibers from skin, subcutaneous and deep tissues and viscera - The (...) of spinal nerves contain efferent (motor) fibers to skeletal muscle, and many contain presynaptic autonomic fibers

Answer 39

- posterior roots - anterior roots

Question 40

The (...) nerve roots unite at their points of exit from the vertebral canal to form a spinal nerve

Answer 40

posterior and anterior

Question 41

- The (...) supply the zygapophysial joints, deep muscles of the back, and overlying skin - The (...) supply the muscles, joints, and skin of the limbs and the remainder of the trunk

Answer 41

- posterior rami - anterior rami

Question 42

Label

Answer 42

Question 43

The dorsal root ganglion has (...) fibers

Answer 43

sensory

Question 44

Label

Answer 44

Question 45

- What contains cell bodies of motor neurons? - What contains cell bodies of sensory neurons?

Answer 45

- ventral horn - dorsal horns

Question 46

Sympathetic nn travel with (...) nerves to the periphery

Answer 46

- somatic (visceral)

Question 47

What is the pathway of sensation in the spinal cord beginning at the skin?

Answer 47

- skin senses something - travels to posterior root - spinal ganglion - posterior horn - anterior horn - anterior root - motor neuron - muscle

Question 48

- Where is gray and white matter located in the cerebral cortex? - Where is it located in the spinal cord?

Answer 48

- gray matter peripherally, white matter centrally - gray matter centrally, white matter peripherally

Question 49

- What is contained in the gray matter of the spinal cord? - What is contained in the white matter?

Answer 49

- gray: nerve cell bodies, unmyelinated fibers - white: myelinated fiber tracts

Question 50

Clusters of nerve cell bodies are located in the (...) of the spinal cord

Answer 50

ventral horn

Question 51

Label

Answer 51

Question 52

- The (...), composed of tough, fibrous, and some elastic tissue, is the outermost covering membrane of the spinal cord. - The spinal dura mater is separated from the vertebrae by the (...) space. - The dura forms the (...), a long tubular sheath within the vertebral canal. - The spinal dural sac adheres to the margin of the (...) of the cranium, where it is continuous with the (...)

Answer 52

- spinal dura mater - extradural (epidural) - spinal dural sac - foramen magnum - cranial dura mater

Question 53

Cranial nerves are (...) nerves; once out of the spinal cord, they are no longer (...)

Answer 53

- peripheral - central

Question 54

What arteries supply the spinal cord?

Answer 54

branches of: - vertebral a - ascending cervical - deep cervical - intercostal - lumbar - lateral sacral

Question 55

What are the 3 longitudinal arteries that supply the spinal cord?

Answer 55

- one anterior spinal artery (formed by union of br. of vertebral aa) - paired posterior spinal arteries (each a br. of vertebral a or posterior inferior cerebellar a)

Question 56

- Spinal cord blood supply is mainly from (...) - There is segmentally reinforced blood supply from (...)

Answer 56

- spinal aa (off vertebral) - spinal br. of cervical, posterior intercostal, lumbar, and lateral sacral aa

Question 57

Label

Answer 57