Flashcards in Chapter 13 Spinal Cord, Spinal Nerves, Spinal Reflexes Deck (184):
What three things can be effectors for both the brain and Spinal Cord?
* Adipose tissue
At what age does the length of the spinal cord stop growing?
What provides a two-way conduction pathway to and from the brain?
How long is the spinal cord?
How wide is the spinal cord?
~18 inches long
~ 1/2 inch wide
At which vertebrae does the spinal cord end?
between vertebrae L1-L2
What is the name for the tip of the spinal cord?
Name the 2 grooves that divide the spinal cord into left and right
Anterior Median Fissure
Posterior Median Sulcus
2 areas of the spinal cord are especially thick due to the amount of gray matter in the segments. Name these two enlargments
(hint: obvious second part to names)
Which two plexus' does the Cervical Enlargement respond to?
* Cervical Plexus
* Brachial Plexus
Which two plexus' does the Lumbar Enlargement respond to?
* Lumbar Plexus
* Sacral Plexus
Name the thin, conical part of the spinal cord below the lumbar enlargement
What is the Filum Terminale made of?
Fibrous Connective Tissue
(an extension of the spinal meninges)
The Filum Terminale extends past the Conus Medullaris and anchors the spinal cord to what?
What do you call the nerve roots extending past the conus medullaris?
What makes up the Cauda Equina?
filum terminale and nerve roots extending
Do the spinal roots continue to lengthen and grow?
(unlike the spinal cord)
Which spinal nerves are named for inferior vertebra while all the other spinal nerves (nerve segments) are named for superior vertebra?
Name the Cervical spinal nerves
Name the Cervical spinal vertebra
How many spinal nerves (spinal cord segments) are found on each side?
Where does the filum terminale exit before it fuses with the coccyx?
How many Sacral Foramina are there, and which Sacral Spinal Nerves go through them?
4 Sacral Foramina
Spinal nerves S1-S4
Which spinal nerves go through the sacral hiatus?
Around which spinal nerve would you find the Cauda Equina?
(end of spinal cord)
Name the two branches of spinal nerves.
Which part of the Dorsal Root contains cell bodies of sensory neurons?
Dorsal Root Ganglia
The Dorsal and Ventral roots join to form what?
a spinal nerve
What do mixed nerves do (carry) ?
carry both Afferent (sensory) and Efferent (motor) fibers
Cranially, the Dura Mater fuses with the __________ of occipital bone and is continuous with cranial dura mater, Caudally the Dura Mater tapers to dense cord of collagen fibers which form what?
* filum terminale in coccygeal ligament
Name the middle meningeal layer of the spinal cord?
What is the name of the space found between the Arachnoid Mater and the Dura Mater?
Name the space found between the Arachnoid Mater and the Pia Mater of the Spine that contains Arachnoid Trabeculae.
Which space would they go into to perform a lumbar puncture or spinal tap to remove CSF?
What is the Arachnoid trabeculae composed from?
network of collagen and elastic fibers
The spinal meninges are continuous with the cranial meninges.
true or false?
Name the 2 functions of the spinal meninges.
*Protect spinal cord
* Carry Blood Supply
What is Meningitis?
Viral or bacterial infection of the meninges
Which space is found in spinal cord but not in the brain?
What space is found in the spine between the dura mater and the walls of the vertebral canal, that contains loose c.t. and adipose tissue?
Name the site (space) of Anesthetic injection
What is the name for the area where the Pia Mater is thick and extends laterally and fuses with the Arachnoid Mater?
When "roots" are mentioned, what are they referring to?
Is there adipose tissue found in the spinal cord?
What does the Denticulate ligament do for the spinal cord?
How many layers make up the cranial Dura Mater?
How many layers make up the spinal Dura Mater?
only 1 layer
Does the spinal nerve (among other things) exit through the Intervertebral Foramen?
Paired denticulate ligaments extend from the pia mater to what other meningeal layer?
The denticulate ligaments stabilize specifically what kind of movement?
side to side
What two main places will you find Blood Vessels (when discussing spinal cord)?
*Along surface of spinal Pia Mater
* within subarachnoid space
What type of Matter surrounds the central canal of the spinal cord?
What three things can be found in gray matter?
neuron cell bodies, neuroglia, and unmyelinated axons
Which of the gray horns contain somatic (SS) and visceral sensory (VS) nuclei?
Posteror Gray Horn
Which of the gray horns contain somatic motor (SM) nuclei?
Anterior Gray Horn
Which of the gray horns contain visceral motor (VM) nuclei?
Lateral Gray Horn
In the sympathetic chain, the sympathetic chain is the "pearl necklace" and the___________ ________ are the" individual pearls"
Which of the two branches of the spinal nerves (roots) contains axons of Sensory neurons?
Which of the two branches of the spinal nerves (roots) contains axons of motor neurons?
Which of the gray horns is found in the thoracic and upper lumbar segments?
Lateral Gray Horn
Sensory nuclei are found in the Dorsal part (posterior). What do Sensory nuclei connect to?
(hint: sensory (Afferent), sensory receptors)
Motor nuclei are found in the ventral part (anterior). What do Motor Nuclei connect to?
(hint: motor (efferent), efferent to effector)
The cell bodies of Neurons in the gray matter of the spinal cord are organized into functional groups called nuclei (aka Sensory nuclei and Motor nuclei).
true or false?
What is another name for tracts (white matter)?
What type of tracts/fasciculi, carry information to the brain?
What type of tracts/fasciculi, carry motor commands to spinal cord from brain or from within the cord to lower levels?
What type of fibers are associated with transverse tracts?
(spand from one side of the cord to the other)
What is covered by a thick layer of white matter?
The Spinal Cord is so highly organized that it is possible to predict results of injuries to specific areas.
true or false?
How many motor neurons are associated with the ANS? and what are they called?
2 motor neurons
pre-ganglionic and post-ganglionic
Name the effector for a Somatic Motor Neuron. What does the Somatic Motor Neuron synapse with
(at the motor end plate)
Name the three options of types of effectors that an Autonomic Motor Neuron would have.
Somatic Afferent associate with sensory receptors from what 3 areas of the body?
* Skeletal Muscle
Visceral afferent associate with sensory receptors from what 3 areas of the body?
* Smooth Muscle
Every spinal cord segment is connected to a pair of ______ ______.
Every spinal nerve is surrounded by three connective tissue layers that support structures and contain Blood Vessels.
true or false?
Name the outermost connective tissue layer of a spinal nerve.
(remember, these are just like the layers of muscle tissue)
Name the C.T. layer of the spinal nerve that surrounds the fascicle (axon bundle)
What is the innermost layer of the spinal nerve that surrounds individual axons?
Where do Ventral Roots and Dorsal Roots unite?
Once a Spinal Nerve branches and forms a pathway to a destination, it then becomes a what?
(outside of spinal cord and brain)
Are there Gray Rami at each spinal level?
Are there White Rami at each spinal level?
White Ramus is only T1-L2
(all of the thoracic and first 2 lumbar)
Why does the White Ramus appear white?
because there are more myelinated than unmyelinated fibers/axons
Which "ramus" contains post-ganglionic fibers Returning from sympathetic ganglion to rejoin spinal nerve? above T1 or below L2
The Dorsal Ramus innervates (serves/supplies) the deep muscles, skin and structures of which area of the body?
supply (an organ or body part) with nerves
Which is the larger branch, the Dorsal Rami or the Ventral Rami?
What areas does the Ventral Rami innervate with? (supply nerves to)
structures of upper and lower limbs of lateral and anterior surfaces of the trunk.
(ventrolateral structures and limbs)
Which branch of the spinal nerves re-enters the vertebral cavity through the intervertebral foramen and supplies the vertebrae, vertebral ligaments, blood vessel of the cord and meninges?
What are the "communicating branches"?
Rami Communicantes contain visceral (sensory and motor) nerve fibers found at the ventral rami of the ________ spinal nerves.
Which spinal cord "space" contains fat and blood vessels?
(found in spine but not brain)
Which space contains CSF?
(between arachnoid mater and pia mater)
What is the name for a complex interwoven network of nerve fibers?
What do you call the interconnecting branches of spinal nerves that are surrounded by the same connective tissue sheaths?
Name the 4 major nerve plexuses.
(hint: there isn't a thoracic plexus)
1. Cervical Plexus
2. Brachial Plexus
3. Lumber Plexus
4. Sacral Plexus
What type of "Rami" do the 4 major nerve plexuses consist of.
(hint: all the same)
What is the area of the spine thats Ventral Ramus does not branch(do not form plexus), and what are these spinal nerves called?
Spinal nerves T2-T12
Can the Ventral Ramus form networks? (branch out, form plexus)
The Cervical Plexus consists of ventral rami of which Spinal Nerves ?
The Brachial Plexus consists of ventral rami of which Spinal Nerves?
The Lumbar Plexus consists of ventral rami of which Spinal nerves?
The Sacral Plexus consists of ventral rami of which Spinal nerves?
The Cervical plexus innervates the diaphragmatic muscles, what is the name of the specific nerve that controls the (skeletal) muscle of the diaphragm?
If you sever your Phrenic nerve, what will happen?
you will die
Which plexus innervates the skin and muscles of your head, neck, superior part of your thoracic cavity (shoulders and chest), and diaphram muscle?
Which plexus innervates the pectoral girdle and upper limbs (skin and skeletal muscle)?
List the 4 Groups of the Brachial.
(hint: Really Tired Drink Coffee)
1. Ventral Rami (Roots)
What's another name for Terminal Branches?
List the 5 major terminal branches of the Brachial Plexus.
(hint: nerves we identified in lab starting near the armpit. Musculoc........)
*Musculocutaneous (nerve) (lateral cord)
*Axillary (nerve) (posterior cord)
*Radial (nerve) (posterior cord)
*Median (nerve) (lateral and medial cords)
*Ulnar (nerve) (medial cord)
Name the 3 Peripheral Nerves (terminal branches) of the Brachial Plexus that service the hands
* Radial Nerve
* Median Nerve
* Ulnar Nerve
Are the nerves of the brachial plexus that supply the hands mixed? (capable of carrying sensory and motor neurons)
Which plexus supplies the anterolateral abdominal wall, external genitalia, and part of the lower limbs?
The Femoral Nerve and the Obturator nerve are both major peripheral nerves of which plexus?
Which plexus supplies the buttocks, perineum, and lower limbs?
Name the 2 peripheral nerves associated with the Sacral Plexus, one is the largest nerve in the body and the other plays the key part in urination
* Sciatic Nerve (largest nerve)
* Pudendal Nerve (key to urination)
Name the two branches of the sciatic nerve
* Tibial Nerve
* Common Fibular nerve
The area of the skin supplied by nerves from a single spinal root
Each spinal nerve contains sensory neurons that serve a specific, predictable segment of the body.
true or false
Which section of spinal cord injury would mainly cause loss of bowel and bladder function as well as sexual dysfunction? This part also controls function of lower legs and feet and genital organs
Sacral spinal cord injury
Are Thoracic spinal cord injuries common or uncommon?
uncommon because of rib cage protection
Which spinal cord injury would cause paralysis or weakness in the legs, also bowel, bladder and sexual dysfunction? (pretty much waist down)
Lumbar spinal cord injury
Which type of spinal cord injury can cause quadriplegia, paralysis in both arms and legs? In some cases respiratory issues and on down, issues in bladder, bowels, genitalia
Cervical spinal cord injury
What is the Medical term for a regional loss of sensory or motor function due to trauma or compression?
Name the virus that attacks neurons in dorsal roots and sensory ganglia of cranial nerves. Connected to chicken pox, lays dormant within neurons of the anterior gray horns and eventually causes skin eruptions following the distribution of the dermatomal innervation
What do you call a rapid, involuntary, automatic response to stimuli?
Which type of neuron far outnumbers the others, sensory neurons, interneurons, or motor neurons?
What are interneurons, unipolar, bi-polar, or multipolar?
There can be any number of interneurons that go up and down until you get to the output.
true or false?
Does a Reflex Arc generally oppose the original stimulus (negative feedback)?
A Reflex Arc begins at a ________ and ends at an ________ (example: muscle fiber or gland cell)
What would be the effector of a Somatic Reflex?
What would be the effector of an Autonomic Reflex?
Name the 5 steps in a Reflex Arc (Reflex Circuit)
(hint: remember a reflex arc starts at receptor ends at effector)
1. Arrival of stimulus, activation of Sensory Receptor (GP)
2. Activation of Sensory Neuron (AP)
3. Integration at CNS (trigger by NT)
4. Activation of Motor Neuron (AP)
5. Response of Peripheral Effector (trigger by NT)
What is the Integrating Center doing in a reflex circuit (arc)?
It is one or more regions within the CNS that relay impulses from sensory to motor neurons
Is your own personal reaction time and tolerance for pain something that's acquired or is it genetic?
What is an innate reflex?
What is an acquired reflex?
What type of reflexes control skeletal muscle?
What are the four ways they classify a reflex?
* complexity of circuit
* processing site
What type of reflex (somatic or visceral (autonomic)) includes superficial and stretch reflexes?
Which type of reflex involves only one synapse and only one segment of the spinal cord?
(one sensory nerve and 1 motor nerve)
Which type of reflex involves more than one synapse and more than one segment of the spinal cord?
Which type of reflex is more common, monosynaptic or polysynaptic?
Which type of reflex (somatic or visceral (autonomic)) control actions of smooth and cardiac muscles, glands, and adipose tissue?
Visceral (autonomic) Reflexes
Are Intersegmental reflex arcs simple or complex?
(they are polysynaptic)
the most complex
What is the best known Monosynaptic reflex?
Why do Monosynaptic reflexes have the least amount of delay between sensory input and motor output?
because they only synapse once and they're done
What are the sensory receptors involved in the stretch reflex called?
Muscle Spindles are composed of small specialized skeletal muscle fibers called what?
intrafusal muscle fibers
What is the name for a sensory receptor that receives stimuli from within the body, especially one that responds to position and movement?
Intrafusal muscle fibers are innervated (nerve supply) by two axons, one sensory one _____.
Name the muscle fiber that surrounds the muscle spindles.
extrafusal muscle fibers
Extrafusal muscle fibers maintain tone and ________ muscle
More precise movement= ____ muscle spindles
Where would you find the sensory region of muscle spindles?
Central region of intrafusal fiber
(center of muscle spindle)
Which part of the sensory neurons spiral around each intrafusal fiber of the muscle spindle?
The sensory neuron of the muscle spindles axon enters CNS through the ______ root.
What is the name for the Motor Neuron of the muscle spindle?
gamma motor neuron
Somatic Motor neuron is associated with which gray horn?
Intrafusal and Extrafusal muscle fibers are ________ muscle fibers.
Since the fibers of the muscle spindles are skeletal muscle fibers, they are associated with _______ Motor Neurons and synapse at the ________ Gray Horn.
Gamma Efferents are important in what type of muscle contractions, voluntary or involuntary?
(remember Gamma motor neurons are associated with skeletal muscle, think back to the divisions of nervous system chart)
(Somatic Motor Neuron)
Gamma Efferents allow the CNS to adjust sensitivity of muscle spindles.
true or false?
In order for a Gamma Efferent to complete the reflex arc, it must synapse back onto __________ fiber of the muscle spindle.
Which specialized muscle fiber found in muscle spindles, detects the amount and rate of change in length of a muscle?
Intrafusal muscle fibers
Everytime you change positions and stretch muscle, your muscle spindles ________ to keep you balanced
What is Reciprocal Inhibition (reciprocal innervation)?
contraction of one muscle, and relaxation of it's antagonist
What type of reflexes are responsible for maintaining upright posture?
(many stretch reflexes are postural)
With Polysynaptic reflexes, Interneurons control more than one ______ group
Polysynaptic reflexes can produce EPSP's(excitatory post-synaptic potentials) or IPSP's(Inhibitory) at CNS motor nuclei.
true or false?
Name the sensory receptors involved in the tendon reflex
Tendon (Golgi Tendon) Organs
Which specific reflex prevents skeletal muscle from developing too much tension and prevents the tearing and breaking of tendons?
Name the reflex responsible for moving a body part away from a stimulus that exerts pain or pressure
(ex: pulls hand away from hot stove)
Withdrawal (Flexor) Reflexes
The Crossed-Extensor Reflex complements the __________ reflex
Crossed-Extensor Reflexes occur on the side ________ to the stimulus
What is the name for a reflex that occurs on the same side of the body as the stimulus?
The Stretch Reflex, Tendon reflex, and withdrawal (flexor) reflex, are all three examples of ___________ reflexes
Name the only reflex discussed that is a contralateral reflex
(occurs on side opposite to stimulus)
Crossed extensor reflex
Superficial Reflexes are elicited by cutaneous stimulation.
true or false?
The Plantar reflex and the Abdominal Reflexes are both examples of ___________ reflexes
(stroking skin for response)
The Plantar reflex and __________reflex are performed the same way except in healthy adults, the plantar reflex makes their toes curl but in infants they call it the _________ reflex because there lack of response is considered normal because their nervous system and corticospinal tract arent fully developed
If an adult has the Plantar reflex test done on them and they do not respond as a normal adult should but actually have the Babinski's reaction, they could possibly have damage to their corticospinal tract or damage to their _______ _____ ______
Primary Motor Cortex