Nervous System // spinal cord
This is a neuron that has one process that branches into a dendrite and an axon.
a unipolar neuron
This is the most common type of neuron in the bran and spinal cord
multiple neurons
This type of neurons that are in the retina of the eye
Bipolar neurons
Sensory neurons that are found in Peripheral Nervous system
Unipolar neurons
This type of neuron has two processes, one dendrite and one axon.
Bipolar neuron
This is the type of neuron found in motor neurons in the peripheral nervous system
multipolar neurons
Basic parts of all neurons
dentrite, cell body, axon
what are located at the ends of an axon?
synaptic knob
this type of neuron has many dendrites & one axon
multipolar neuron
What connects the neuron to a muslce/gland/another neuron?
synapse (a small space)
Where is the neural impulse created?
a dendrite
Name 5 regions of the spinal cord
Cervical, thoracic, lumbar, sacral, coccygeal
State the number of pairs exiting out of the s
8 cervical, 12 thoracic, 5 lumbar, 5 sacral
True/false motor neurons are located in the ventral root
False
True/false somatic visceral motor neurons are located in the anterior & lateral grey horns
True
What kind of nerves does spinal nerve contain.
Mixed
What are meningi?
Coverings of the brain
What are the 3 meninges that cover the brain?
dura mater, arachnoid, pia mater
What do the Spinal Meninges provide?
Physical support, shock absorption CFS & blood vessels deliver nutrients & oxygen
True/False:
Spinal Meninges are continues with the cranial meninges
True
What kind of tissue is the Arachnoid meningi made up of?
Epithelium
What does the denticulate ligament prevent?
lateral movement of the cord (side-to-side)
in what two spinal regions is the lateral horn found in?
The theracic & Lumbar
Cell bodies of motor neurons are found here
ventral gray horn
This Layer of the spinal cord contains large number sof axons organized in tracts & columbs
White Matter
What kind of nuclei do the gray horns contain?
somatic & visceral
The location of somatic motor nuclei
anterior gray horn
This location contains visceral motor nuclei
Lateral grey horn.
Also associated with sympathetic portion of Autonomic system
Where do the cervical enlargements supply nerves to?
shoulder girdles and upper limbs
This layer of the spinal cord contains cell bodies of neurons, neuroglia & unmyelinated axons
Gray matter
where do lumbar enlargements supply nerves to?
pelvis and lower limbs
What is the filum terminale?
slender strand of fibrous tissue, extending from the tip of the concus medullaris, to sacral vertebra providing longitudinal support of the spinal cord
True/False
After age 4 the vertebral column continues to elongate; spinal cord does now.
True.
Where does the adult spinal cord extend down to?
down to the second lumbar vertebra
continuation of nerves after the spinal cord that start around the L2 level are called this ___
hint: it looks like a horse's tail in a gross dissection
Cauda Equina
What is another name for a tract?
Fasciculus
What is a tract?
bundle of axons that relay the same type of information (uniform in respect to diameter, mylination & conduction speed
What do Ascending (afferent) tracts carry?
Sensory information toward the brain
What do descending (efferent) tracts carry?
Motor commands to the spinal cord
What two things decussate in the Spinal cord?
both sensory & motor information
ex: left side of the brain receives sensory information from the right side of the body & sends its motor commands to that side
How does ascending tracts work?
hint: there are 3 steps
First order: caries info to periphery from spinal cord where it synapses with 2nd order neuron
Second order neuron: Carries information from spinal cord to thalamus & synapses with 3rd order neuron.
Third order neuron: Carries info from thalamus to sensory cortex. This is where sensation is localized
Where is sensation first noticed?
Thalamus
True/False
Upper motor neuron is a PNS tissue
False. It is a CNS tissue
True/False
Nerves are part of the peripheral nervous system
True
True/False
Perineurium encloses all of the fascicles and forms the tough fibrous sheath enclosing the nerve
False. This is the Epineurium. The Perineurium bundle axons into fascicles
Where is the cervical plexus located?
c1-c5
Where is the brachial plexus located?
c5-T1
Where is the intercostal nerves located?
T1-T12
Where is the lumbar plexus located?
L1-L4
Where is the Sacral plexus located?
l4-s4
What is the major nerve running through the cervical plexus?
Phrenic nerve
What are the Nerves that are found in the brachial plexus?
Radial, ulnar, median, axillary
Largest nerve of the lumbar plexus
Femoral nerve
Where does the sacral plexus innervate?
Buttocks and lower limb
What nerve branches from the tibial and common fibular nerve?
Sciatic nerve
What is the purpose of reflexes?
To preserve homeostasis by making rapid adjustments in the function of organs
True/False
Reflexes can be learned
True
True/False axon sensory neurons sends impluse to the spinal cord by way of ventral root
False. Dorsal root
When you lean on a hot stove & pull your hand away, what kind of reflex is it?
Spinal cord reflex
Steps in a spinal cord reflex
1. arrival of stimulus
2.the activation of sensory neuron
3.Information processing by integration center
4.The activation of a motor neuron
5.The response of a peripheral effector
Which is NOT an example of a somatic stretch reflect
Knee jerk reflex or Rooting reflex
Rooting reflex
True/False
Most reflex arcs are polysynaptic, involving one or more interneurons
True
True/False
Ipsilateral reflex arcs have the sensory input and motor output on the opposite side of the CNS
False
True/False
Intersegmental reflex arcs have their output at a different vertical level of the spinal cord than their input
True
Which of the following reflexes is NOT an example of somatic reflex?
Reciprocal inhibition, corneal reflex, postural reflex, golgi tendon relfex
Corneal reflex. This is a type of Innate reflex