Module 2 - Gross Anatomy and Internal Structure of Spinal Cord and Brainstem Flashcards
What is the denticulate ligament and what is its function?
- It is a thickening of pia and glial elements. It forms a “ribbon along the lateral surface of the spinal cord
- It attaches the cord to and suspends it in dura/arachnoid tube
What are the 2 enlargements of the spinal cord?
Cervical enlargemetn (c4-5 - T1)
Lumbisacral enlargement (L2-S3)
What is the Filum terminale?
- extension of pia and supporting cells
- anxhors spinal cord to dorsum of coccyx
What is a potential space?
A region of the body in which two surface membranes adjoin, separated in health only by a small amount of fluid lubrication.
Identify the:
- epidural space
- dura mater
- arachnoid mater
- pia mater
- subdural space
What are the denticulate ligaments? Identify them.
projections of pia mater that stabilize the spinal cord
What is the anterior horn of spinal cord?
the ventral (front) grey matter section of the spinal cord which contains motor neurons that affect the skeletal muscles
What is the Posterior horn of spinal cord?
the dorsal (towards the back) grey matter section of the spinal cord that receives several types of sensory information from the body including light touch, proprioception, and vibration
On this micrograph of the spinal cord, locate the:
- posterolateral sulcus
- posterior median fissure
- posterior horn
- anterior horn
- anterior median fissure
- central canal
- anterolateral sulcus
What are the 4 categories of bone case around the spinal cord (top to bottom)
- cervical
- thoracic
- lumbar
- sacral
What is a segment in the spinal cord?
A portion of the cord giving rise to a spinal nerve
How many segments are there in the human spinal cord?
31
If there are 31 spinal nerves, how many are:
a. cervical
b. thoracic
c. lumbar
d. sacral
e. coccygeal
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
Moving caudally down the chord, the length of roots increases - why?
What is the longest root?
Because they must travel further to exit through the appropriate intervertebral foramen.
lumbosacral roots are the longest and form the cauda equina
Describe rootlets of the spinal cord
They are either motor (anterior) or sensory (posterior). They combine outside the vertebral canal into spinal nerves that are mixed
Identify the:
- Posterior root (sensory)
- Anterior (ventral) root (motor)
- Spinal nerve (mixed
What is the spinal, or dorsal root, ganglion?
a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia.
Where is:
- Spinal ganglion
- Posterior (dorsal) roots - sensory
- Anterior (ventral) roots - motor
- Spinal nerve - mixed
Inner core of spinal core grey matter consists of what?
nerve cell bodies and processes,
neuroglia
what does the posterior horn of the spinal cord do?
Receives and processes sensory information
What does the anterior horn do?
motor
Location of cell bodies of nerves innervating skeletal muscles (i.e. lower
motor neurons [LMN])
What does the central canal of the spinal cord become continuous with?
the 4th ventricle in the medulla
Rexed’s laminae
Gray matter divided into layers in the spinal cord
There are 3 main columns of white matter (consisting of axons and neuroglia) in the spinal cord, what are they?
- posterior (dorsal) column
- lateral column
- anterior (ventral column)
What are the major tracts of the posterior/dorsal white matter column?
fasciculus gracilis (carries tactile and proprioceptive information from the lower half of the body)
fasciculus cuneatus (fiber bundle that carries tactile and proprioceptive information from the upper limbs and torso)
fasciculus cuneatus
fiber bundle that carries tactile and proprioceptive information from the upper limbs and torso
fasciculus gracilis
carries tactile and proprioceptive information from the lower half of the body
What are the major tracts of the lateral column of the spinal cord?
lateral corticospinal tract (descending motor pathway)
rubrospinal tract (descending motor pathway) spinocerebellar tracts (ascending proprioceptive pathway to cerebellum)
What are the three anterior/ventral column tracts?
- spinothalamic tract (anterolateral system) - ascending sensory (v. imp)
- vestibulospinal tracts (lateral and medial) - descending balance
- reticulospinal tracts (lateral and medial) - descending - v. old - preparatory movement related
Sensory information enters the spinal cord through what?
Motor information leaves the spinal cord through what?
The posterior roots
The anterior roots
Primary [blank] autonomic fibers
have their cell bodies in the lateral horn and leave the spinal cord through the anterior
root.
Primary efferent autonomic fibers
have their cell bodies in the lateral horn and leave the spinal cord through the anterior
root.
[blank] autonomic fibers travel with somatic [blank] through the posterior root.
Afferent autonomic fibers travel with somatic afferents through the posterior root.
What is the interomediolateral nucleus?
A lateral horn lying at spinal cord levels T1–L2 and S2–S4; it
contains the motor efferent cell bodies of the visceral motor
system.
LMN
Lower motor neurons
Gray matter contains the cell bodies of the spinal cord. Which cell bodies in particular in the anterior horn?
LMNs and modulatory interneurons called Renshaw cells
What does white matter in the spinal cord contain?
All ascending information to higher centers in the brainstem and forebrain, as well as all descending information to spinal cord neurons.
The ascending information is mainly sensory from the body
The descending information is motor to the LMNs; in addtion there are descending sensory fibers that modulate sensory input (mainly pain)
What does fasciculi mean?
Latin for bundles
On this anterior image of the brainstem, locate the:
- interpeduncular fossa
- cerebral peduncle
- Mammillary bodies (hypothalamus)
- pyramids
- olives
6 anterior median fissure
On this posterior image of the brainstem, locate the:
- superior colliculus
- inferior colliculus
- superior cerebellar peduncle
- inferior cerebellar peduncle
- middle cerebellar peduncle
- obex
- fasciculus gracilis
- fasciculus cuneatus
On this coronal brain slice, where is the thalamus?
On this coronal brain slice (#14), where is the thalamus?
On this coronal brain slice, with the thalamus highlighted, where is the third ventricle?
On this coronal brain slice, with the thalamus highlighted, where is the caudate nucleus?
On this coronal brain slice, with the thalamus highlighted, where is the internal capsule?
On this horizontal brain slice, where is the thalamus?
On this horizontal section of the cortex, showing the thalamus, where are the lateral ventricles?
On this horizontal section of the cortex, showing the thalamus, where is the third ventricle?
On this horizontal section of the cortex, showing the thalamus, where is the caudate nucleus?
On this horizontal section of the cortex, showing the thalamus, where is the internal capsule?
On this mid-saggital section of the brain, identify:
- anterior commissure
- 3rd ventricle
- thalamus
- hypothalamic sulcus
- hypothalamus
- mammillary body
On this coronal section of the brain, locate the subthalamus.
Also, describe its location.
Inferior to thalamus, between thalamus and tegmentum of midbrain, caudal to
hypothalamus.
On this coronal section of the brain, showing the subthalamus/subthalamic nucleus, located the red nucleus.
On this coronal section of the brain, showing the subthalamus/subthalamic nucleus, located the substantia nigra.
What does the telencephalon consist of?
The cerebral hemispheres and the corpus striatum (caudate, putamen, globus pallidus) which is part of the basal ganglia
Of what is the corpus striatum comprised?
caudate, putamen, globus pallidus
Of what does the internal capsule consist?
projection fibers that travel to and from the cortex; and descending fibers to striatum, brainstem and spinal cord
The internal capsule forms a fan beneath the cortex, what is this called?
corona radiata
On this horizontal brain slice, where is the hypothalamus?
