Exam 1: Spinal Cord
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Exam 1: Spinal Cord
anatomy spinal cord
Review of 6/5 lecture on the spinal cord for anatomy exam 1
How long is the vertebral canal in an adult?
extends from the foramen magnum to L2 vertebra
How long is the vertebral canal in a smal child?
extends to L3 vertebra
How long is the vertebral canal in a 3-month old fetus?
extends to the coccyx
Which grows faster, the vertebral column or the spinal cord?
What is the length of the spinal cord in the adult?
18 inches (45cm)
Name the enlargements of the spinal cord?
cervical enlargement and lumbar enlargement
What is the purpose of the cervical enlargement?
provide origin for nerves to upper extremity (has larger anterior horns)
What is the purpose of the lumbar enlargement?
provides origin for nerves to lower extremity
What type of neurons originate in the ventral (anterior) horn of the spinal cord?
How many types of nerve rootlets are there?
How do nerve rootlets get their name?
named according to their relative positions
What are the 2 types of nerve rootlets?
dorsal (posterior) rootlets
ventral (anterior) rootlets
The dorsal rootlets form:
dorsal nerve root
The ventral rootlets form:
ventral nerve root
The dorsal and ventral nerve roots merge to form:
the end of the spinal cord
termination of spinal cord
collection of nerve roots streaming inferiorly below the conus medularis
Where is the pia mater located?
it is the most intimate covering of the spinal cord
forms outer layer of spinal cord
formed by pia mater at inferior limit of spinal cord
lateral extensions of pia mater which attach to inner surface of dura mater
What is the function of denticulate ligaments?
anchor spinal cord to the dura mater
How many layers of tissue does the arachnoid membrane have?
What is the texture of the outer layer of the arachnoid membrane?
Where is the outer layer of the arachnoid membrane?
in physical contact with the dura mater
Describe the inner layer of the arachnoid membrane:
gives rise to fibers that pass to the pia mater, thereby transversing the subarachnoid space
Where does the arachnoid membrane extend to?
the level of S2 vertebra
Where is the subarachnoid space?
between the arachnoid membrane and pia mater
What is the subarachnoid space filled with?
cerebrospinal fluid (CSF)
Where can a needle be inserted to gain a sample of CSF?
between L4/L5 or L5/S1 vertebra
What is the length of the subarachnoid space?
extends from the cranial cavity to level of S2 vertebra
continuous with cranial subarachnoid space
How far does the dura mater extend?
continuous with cranial dura mater
extends to level of S2 vertebra
What is the dura mater composed of?
tough collangenous tissue
Is there a subdural space?
in pathological situations the dura mater can be separated from the arachnoid membrane by fluid or tumor tissue
subdural space is normally a "potential space" --since the dura mater is normally in contact with the arachnoid membrane no space is present
How far does the subdural space extend?
to the level of S2 vertebra
How far does the epidural space extend?
from foramen magnum to sacrum (sacral canal)
Where is the epidural space located?
between spinal dura mater and vertebral canal
What is contained in the epidural space?
blood vessels (internal vertebral venous plexus), fat, fatty connective tissue
What is the epidural space good for?
regional anesthesia such as an "epidural"
NN absorb and relieves pain
How many spinal nerves are there?
How many cervical spinal nerves?
How many thoracic spinal nerves?
How many lumbar spinal nerves?
How many sacral spinal nerves?
How many coccygeal spinal nerves?
One pair of spinal nerves corresponds to...
one spinal cord level, from which it originates
What is a dermatome?
an area of skin innervated by one pair of spinal nerves
What forms the anterior spinal artery?
union of two anterior spinal branches of the two vertebral AA
How far does the anterior spinal artery descend?
to the conus medullaris
Posterior spinal arteries (L/R) are branches of:
Which is smaller? posterior spinal arteries or anterior spinal artery?
posterior spinal arteries
How do segmental spinal arteries enter the vertebral canal?
The cervical branches of the segmental spinal arteries orginate from:
vertebral arteries, thyrocervical trunk and costocervical trunk
Where do the thoracic branches of the segmental spinal arteries come from?
posterior intercostal arteries
Where do the lumbar branches of the segmental spinal arteries come from?
What do the segmental arteries supply?
contents of epidural space
contents of vertebral canal
Which side of the body is the Artery of Adamkiewicz on?
What is the Artery of Adamkiewicz also known by?
greater anterior medullary A
What does the artery of Adamkiewicz do?
reinforces circulation to lumbar enlargement of spinal cord
What artery does the artery of Adamkiewicz anastomosis with?
anterior spinal A
Where does the artery of Adamkiewicz come from?
Where does the spinal cord drain blood to?
a venous plexus (network) on the surface of the spinal cord
Where is the spinal venous plexus located?
in the subarachnoid space
What do the surface venous plexus connect to?
internal vertebral plexus
Where are internal vertebral plexus located?
Where do the internal vertebral plexus drain to?
Where do the intervertebral veins drain?
to the external vertebral plexus
Where are the external vertebral plexus?
surrounds vertebral column
External vertebral plexus receive blood from:
internal venous plexus
Do the vertebral venous plexuses hae functional valves?
What does it mean for the vertebral venous plexuses to have no functional valves?
blood can flow in any direction as influenced by gravity
What are included in Batson's veins?
external and internal vertebral venous plexuses
connects cranial cavity with venous plexuses in the pelvic cavity
Since there are no valves in the vertebral plexuses, what could happen with metastatic cells originating in the pelvic region?
They can travel to the cranial cavity where secondary malignant tumors can develop
What is the dorsal root ganglion?
collection of nerve cell bodies in the PNS
The dorsal nerve root of the spinal cord has what kind of neurons?
The ventral nerve root of the spinal cord has what kind of neurons?
The dorsal and ventral primary rami have what kind of neurons?
both sensory and motor
skin, skeletal muscle, and bone
sensory from soma TO spinal cord
motor FROM spinal cord to skeletal muscles
General Somatic Afferent detects:
touch, pressure, pain, and temperature
In the General Somatic Afferent, information goes to:
spinal cord and then brain
General Somatic Efferent information goes to: