Lecture Unit 4 Exam Study Guide

What is a nerve?

bundle of fibers in the body that transmit electrical impulses from the brain, spinal cord, and to the rest of the body, making up the nervous system

What are the support cells of the CNS?

astrocytes
microglia cells
ependymal cells
oligodendrocytes

What is the function of astrocytes?

helps with glutamate uptake from synapse & ion control
forms scar around injury so it cannot get bigger, but neuron cannot get past meaning it cannot regenerate

What is the function of microglia cells?

engulf invading microorganisms & dead neurons

What is the function of ependymal cells?

circulate CSF & line CSF cavity

What is the function of oligodendrocytes?

produces myelin sheath in CNS

What are the support cells of the PNS?

satellite cells
schawnn cells

What is the function of satellite cells?

no known function

What is the function of schawnn cells?

create myelin sheaths in the PNS

Which cells are responsible for myelination in the CNS?

oligodendrocytes

Which cells are responsible for myelination in the PNS?

schawnn cells

What is the difference between gray and white matter

gray matter - houses cell bodies
white matter - houses axons

Is nerve regeneration possible in the CNS?

no because of the astrocytes that create a barrier that does not let anything past

Is nerve regeneration possible in the PNS?

yes

Is sensory effector or affector?

affectors

Is motor effector or affector?

effector

What are the two types of sensory nerves

somatic & visceral

What does the somatic sensory nerve deal with in general?

touch, pain, pressure, vibration, temperature, & proprioception in skin, body wall, & limbs

What does the visceral sensory nerve deal with in general?

stretch, pain, temperature, chemical changes, & irritation in vescera; nausea & hunger

What are the two types of motor nerves?

somatic & visceral

What do motor somatic nerves deal with in general?

voluntary; motor innervation of all skeletal muscles

What do motor visceral nerves deal with in general?

motor innervation of smooth muscle, cardiac muscle, & glands; equivalent to autonomic nervous system (ANS)

What are the structural types of neurons?

multipolar
bipolar
unipolar

What are multipolar neurons?

most common in CNS
2 or more dendrites
always motor

What are bipolar neurons?

1 axon & 1 dendrite
olfactory cells, retina, ear
always sensory
cell body in middle + two poles from each side
1 pole ends with dendrites & other ends with axon terminals

What are unipolar neurons?

single process from soma
pseudounipolar
peripheral process
central process
always sensory
starts in dermis & ends in spinal cord
similar to bipolar, but cell body sits in process & has peripheral process & central process

What are the functional classes of neurons?

sensory neurons
interneurons
motor neurons

Are sensory neurons afferent or efferent?

afferent

Are motor neurons afferent or efferent?

efferent

What are sensory neurons?

originate in PNS & end in CNS
bring in sensory information from the outside world

What are interneurons

always in CNS; process, store, retrieve, make decision, 90% of all neurons
integrate all info from sensory neurons; take sensory input & make decision/compare it to past experiences/bring up old memories; make motor decision; communicate with motor neurons

What are motor neurons?

originate in CNS & terminate/synapse in PNS onto effector cells
communicate with skeletal, cardiac, & smooth muscle

What is a sulcus?

grooves of cerebral cortex

What is a gyrus?

bumps of cerebral cortex

What is a fissure?

divides the hemispheres & follows the sagittal suture

What are the meningeal layers of the brain?

dura mater
arachnoid mater
pia mater

What is the function of the dura mater?

protects brain & spinal cord
provides physical barrier
drains blood from brain

What is the function of arachnoid mater?

provides cushioning for brain & spinal cord
subarachnoid space serves as shock absorber & medium
CSF circulates & distributes nutrients & removes waste

What is the function of pia mater?

final layer of protection
contain small blood vessels that supply oxygen & nutrients to CNS

What is the relationship between the central sulcus, primary somatosensory cortex and primary motor cortex?

the central sulcus divide the primary somatosensory cortex & primary motor cortex

What are the cortical areas?

Motor area
sensory area
association area

What is the function of the motor area?

controls voluntary motor functions

What is the function of the sensory area?

conscious awareness of sensation

What is the function of the association area?

integrate diverse info into action

How do the cortical areas work together?

allow brain to process & integrate sensory input, plan movements, communicate through language, regulate emotions, & create memories, allowing us to survive

What is a homunculus?

visual representation of how the human body is mapped onto the brain within motor & sensory cortices

What is a homunculus in the sensory area?

representation of sensory input

What is a homunculus in the motor area?

represents the motor control over the body

What is the function of the corpus callosum?

structure made of white matter that connects the 2 hemispheres to communicate

What is the function of the ventricles?

hollow chambers that house CSF

What is the function of the thalamus?

acts as a gateway for interneurons or when sensory neurons enter the brain

What is the function of the pineal gland?

melatonin, circadian rhythm, regulation, seasonal rhythms

What are the two parts of the corpora quadrigemina?

superior & inferior

What is the functional of the superior corpora quadrigemina?

visual & vision reflexes

What is the function of the inferior corpora quadrigemina?

hearing & auditory reflexes

What is the function of the pons?

hearing, facial sensations, taste, saliva, tears, facial expression, equilibrium, eye movement (lateral rectus)

What is the function of the medulla oblongata?

regulates blood pressure, heart beat/rate, & breathing

What are the two types of matter found in the spinal cord?

white matter & gray matter

What surrounds gray matter in the spinal cord?

white matter

What does the white matter of the spinal cord surround?

gray matter

What are the components of white matter?

dorsal columns & lateral columns

What is the function of a dorsal column?

carry sensory information related to touch, proprioception, & vibration from the body to the brain
divides white matter into dorsal & lateral & ventral

What is the function of lateral columns?

contain ascending sensory tracts & descending motor tracts

What are the components of the gray matter>

dorsal horn & ventral horn

What does the dorsal horn deal with?

sensory
somatic sensory
visceral senosry

What does the ventral horn deal with?

motor
somatic motor
visceral motor

What is the function of the lateral corticospinal pathway?

pathway in CNS responsible for volutnary motor control, skilled movements of limbs & hands

What is the name of nerve I?

olfactory nerve

Is nerve I sensory, motor, or sensory & motor?

only sensory

Where does nerve I intervate?

olfactory epithelium in nasal cavity

Where does nerve I termiante?

olfactory bullb

What is the name of nerve II?

optic nerve

Is nerve II sensory, motor, or sensory & motor

sensory only

Where does nerve II intervate?

retina

Where does nerve II terminate?

lateral geniculate nucleus (LGN)

What is the name of nerve V?

trigeminal nerve

Is nerve V sensory, motor, or sensory & motor?

sensory & motor

Where does nerve V intervate?

3 terminal branches / face’s sensory areas

Where does nerve V sensory terminate?

brainstem

Where does nerve V motor terminate?

muscles of mastication

What are the 5 components of spinal reflex?

receptor
sensory neuron
interneuron
motor neuron
effector

How is a reflex different from typical processing involving the brain

reflex is different from typical processing regarding the brain because a reflex is much faster and requires a myelin sheath around the axon so that the electrical signal reaches the axon terminals faster

What are the different types of reflexes?

Monosynaptic
polysynaptic
ipsilateral reflex
contralateral reflex