Spinal Cord, Nerves & Blood Supply

Question 1

Spinal Cord (+ functions)

Answer 1

Relays information to and from the brain, performs some integrative activities (reflexes), originates from the base of the skull (foramen magnum), spinal cord ends at 1st lumbar vertebra

Question 2

Spinal Nerves

Answer 2

Bundles of axons connected to the spinal cord, nerves exit the vertebral canal at the end level of the origin and destination, form nerve plexuses that innervate skin and skeletal muscles

Question 3

Innervate

Answer 3

Provide nerves to

Question 4

Cervical Spinal Nerves

Answer 4

Innervates neck and diaphragm muscles

Question 5

Brachial Spinal Nerves

Answer 5

Innervates pectoral girdles and upper limbs

Question 6

Lumbosacral Spinal Nerves

Answer 6

Innervates pelvic girdle and lower limbs

Question 7

Cauda Equina

Answer 7

The end of the spinal cord, the remaining nerves of the spinal cord extend inferiorly and resemble a horse tail

Question 8

Make-up of Peripheral Nerve

Answer 8

Axons are surrounded by endoneurium -> bundles of axons are called fascicles -> fascicles are surrounded by perineurium -> collective fascicles, blood vessels, and other connective tissues are surrounded by epineurium

Question 9

Precentral Gyrus

Answer 9

Anterior to the central sulcus, controls voluntary movement, pre-motor cortex - planning of movement

Question 10

Postcentral Gyrus

Answer 10

Posterior to central sulcus, receives sensory information

Question 11

Spinothalamic

Answer 11

Basic sensory pathway

Question 12

Corticospinal

Answer 12

Motor pathway

Question 13

Reflex Pathway

Answer 13

Integration in spinal cord

Question 14

The Brain and Spinal Cord are Protected from Mechanical Forces by:

Answer 14

Cranial bones & vertebrae, meninges, cerebrospinal fluid (CSF)

Question 15

Three Layers of Meninges

Answer 15

Dura mater, arachnoid mater, pia mater

Question 16

Dura Mater

Answer 16

Outermost layer of meninges, fibrous layer that is fused to the periosteum

Question 17

Arachnoid Mater

Answer 17

Middle layer of the meninges, smooth membrane that covers the brain and spinal cord, contains blood vessels (subarachnoid space - contains blood vessels and cerebrospinal fluid)

Question 18

Pia Mater

Answer 18

Delicate tissue layer of the meninges adhered to the surface of the brain and the spinal cord

Question 19

Dural Folds (in the Dura Mater)

Answer 19

Falx cerebri, tentorium cerebelli, falx cerebelli, dural sinus

Question 20

Falx Cerebri

Answer 20

Fold of dura mater that projects between the cerebral hemispheres

Question 21

Tentorium Cerebelli

Answer 21

Separates the cerebral hemispheres from the cerebellum

Question 22

Falx Cerebelli

Answer 22

Separates the 2 cerebellar hemispheres (in the mid-sagittal line, inferior to the tentorium cerebelli)

Question 23

Dural Sinus (aka Superior Sagittal Sinus)

Answer 23

Large collecting vein within dural folds

Question 24

Ventricles

Answer 24

Produced during brain development, filled with cerebrospinal fluid (CSF), lined with specialised cells (ependymal cells)

Question 25

Cerebrospinal Fluid (CSF)

Answer 25

Constantly produced and maintained within the ventricles in the area called the choroid plexus -> circulates through the ventricles and fills the the central canal of the spinal cord -> enters the subarachnoid space & circulates around the brain, spinal cord & cauda equina -> drained from the subarachnoid space through arachnoid granulations into the dura mater -> absorbed into venous circulation via the superior sagittal sinus

Question 26

Brain Receives Blood Through the Arch of the Aorta via:

Answer 26

Vertebral artery, internal carotid artery, left and right sides [collectively called the cerebral arterial circle]

Question 27

Blood-Brain Barrier (BBB)

Answer 27

Isolate the CNS from chemicals and hormones circulating the blood, maintained by astrocytes which wrap around blood vessels

Question 28

What can go Wrong with Blood Supply to the Brain?

Answer 28

[Blood supply interrupted (cerebrovascular accident), brain cells die due to lack of oxygen, disruption of blood flow (restrict oxygen flow to cells)] - can cause blockages & ruptures (aneurysm)