PHSL 301 Exam 3

What kind of cell is specialized to conduct an action potential?

Neuron

What is a neuron?

the structural and functional unit of the nervous system; It is highly specialized to conduct action potentials and they don’t typically regenerate. They also have a high metabolic rate (require abundant supply of O2 and glucose)

How do neurons conduct action potentials and communicate?

By the flow of ions down their axons, and they communicate via neurotransmitters

If the dendrites of a neuron are destroyed, the cell will not be able to

receive synaptic activation

What are nissl bodies?

cluster of rough ER that produce abundant proteins

What do neurofibrils do?

provide cell shape

What is the axon hillock?

the termination of the cell body

What do dendrites do?

They are the input region; receives info via neurotransmitters

What do axons do?

Generate and transmit impulses

What are the synapses?

the site of communication between 2 neurons or between a neuron and its effector

What cell type within the CNS makes the myelin sheath?

oligodendrocyte

What cell type produces CSF?

ependymal cell

What are astrocytes?

The largest, most abundant glial cell. They are major support cells of the neurons and form the Blood Brain Barrier (BBB)

What are microglia?

the immune cells of the CNS. They monitor neuronal health and can phagocytize foreign material and neuronal debris

What are ependymal cells?

ciliated simple epithelium that line the cavities of the brain and spinal cord and produce cerebrospinal fluid (CSF)

What are oligodendrocytes?

they wrap their fibers around the axons of the neurons in the CNS to create the myelin sheath

What are satellite cells?

principal glial cells of the PNS. Supply nutrients to the surrounding neurons and also have some structural function

What are Schwann cells?

they form the myelin sheath for the PNS neuronal axons; vital for regeneration of PNS fibers

A neuron that has ONE axon and ONE dendrite emerging from the cell body would be classified as

a bipolar neuron

What are the three structural classes of neurons?

multipolar, bipolar, and unipolar

What are multipolar neurons?

the most common; ONE axon, TWO or MORE dendrites

What are bipolar neurons?

found in special sense organs; ONE axon and ONE dendrite

What are unipolar neurons?

found in the PNS as sensory neurons; 1 process that emerges from the soma and then splits into a central and a peripheral process (axon and dendrite)

What are the three functional classifications of neurons?

sensory (afferent), motor (efferent), and interneurons (association)

What do sensory (afferent) neurons do?

UNIPOLAR; transmit impulses from sensory receptors within the body TOWARDS the CNS (ARRIVE=AFFERENT)

What do motor (efferent) neurons do?

MULTIPOLAR; carry impulses FROM the CNS to effector organs (EFFERENT=EXIT)

What do interneurons (association) neurons do?

MULTIPOLAR; between sensory and motor neurons, where integration occurs

What kind of amino acid neurotransmitter is GABA?

inhibitory

What kind of amino acid neurotransmitter is glutamate?

excitatory

What kind of peptide neurotransmitter is cholecystokinin?

excitatory

What kind of peptide neurotransmitter is somatostatin?

inhibitory

What kind of amine neurotransmitter is norepinephrine?

excitatory

What kind of amine neurotransmitter is dopamine?

both inhibitory and excitatory

What kind of amine neurotransmitter is serotonin?

inhibitory

What kind of neurotransmitter is acetylcholine?

both inhibitory and excitatory

What kind of gas neurotransmitter is nitric oxide?

excitatory

What kind of lipid neurotransmitter is endocannabinoids?

inhibitory

Multiple sclerosis is an autoimmune disease that causes

loss of myelin sheath

What is multiple sclerosis?

an autoimmune disease in which the body’s immune system attacks the myelin sheath

What are symptoms of MS?

paresthesia (deceased/abnormal sensation), muscle weakness, dysphagia (difficulty swallowing), ataxia (loss of coordination and balance), and inability to control bowel and bladder

secondary vesicles and brain regions of the prosencephalon

telencephalon and diencephalon; cerebrum, basal ganglia, limbic system nuclei and tracts

secondary vesicles and brain region of the mesencephalon

mesencephalon; midbrain

secondary vesicles and brain regions of the rhombencephalon

metencephalon and myelencephalon; pons and cerebellum, and the medulla oblongata

You have a patient that has lost the ability to speak fluently. She has a problem producing speech. She has no problems understanding speech. What area is likely damaged?

Broca’s area

Where are the motor areas of the cortex (voluntary movement) located?

posterior FRONTAL lobe

Where are the primary motor areas of the cortex located?

PRE-central gyrus

What is association area of the motor areas of the cortex?

Broca’s area

What is Broca’s area responsible for?

speech production (movement of tongue/lips) If damaged, speech is slurred

what are the sensory areas of the cortex associated with?

associated with conscious awareness and sensation

Where are the sensory areas of the cortex located?

the parietal, occipital, temporal, and insular lobes

Where is the primary somatosensory area located?

POST-central gyrus

What do the sensory association areas do?

they integrate information from the sensory areas

What is Wernicke’s area?

it is responsible for interpretation of speech; If it is damaged, the person cannot understand what you are saying OR what THEY are trying to say

What is Wernicke-Korsakoff syndrome and how can you get it?

It is actually NOT associated with damage to Wernicke’s area; it is also known as “wet-brain”, which is primarily caused by a thiamine (b1) deficiency. You can get it from severe alcohol abuse, which can interfere with the body’s ability to absorb b1.

Alzheimer’s disease is a neurodegenerative disease that leads to progressive cognitive decline. Neuropathological changes occur first within the

hippocampus

What is the limbic composed of?

Cerebral nuclei and fiber tracts that encircle the upper brain stem; includes: hippocampus, amygdala, hypothalamus, cingulate gyrus, fornix, parahippocampal gyrus, dentate gyrus, mammillary bodies, and olfactory bulbs

What are the major functions of the limbic system?

emotion, smell, and memory

What is the limbic system most often tied with?

The pre-frontal cortex

What is the limbic system responsible for?

goal directed behavior

What is the primary area for memory?

the hippocampus is the primary area

What is the amygdala responsible for?

fear/anger/aggression

What happens to the brain when developing Alzheimer’s Disease (AD)?

the hippocampus develops a large amount of amyloid plaques and neurofibrillary tau tangles preventing neurotransmission

What can disorder of the basal ganglia lead to?

Parkinson’s disease; symptoms include resting tremors (tremors go away when you move) and difficulty initiating walking

What happens during a stroke?

A stroke occurs when blood circulation to the brain STOPS, leading to an ischemic attack (loss of O2) causing death of brain tissue. The outcome will depend on area of damage; it is the 3rd leading cause of death

what is white matter composed of?

myelinated/unmyelinated axons; FIBER TRACTS

What is gray matter composed of?

neuron cell bodies and interneurons

What are gray matter clusters that RESIDE in WHITE matter made up of?

nuclei

Where are gray/white matter distributed in the brain vs. the spinal cord?

In the brain, gray matter is on the outside with white matter on the inside/contains nuclei; In the spinal cord, white matter is on the outside with gray matter deep inside (H shape)

A projection tract conducts nerve impulses from

the cerebrum to lower parts of the CNS

white matter association tracts

impulses from one area of a hemisphere to another area in the SAME hemisphere

white matter commissural tracts

impulses from one are in one hemisphere to the corresponding area in the opposite hemisphere; CORPUS CALLOSUM

white matter projection tracts

impulses from the cerebrum to lower parts of the CNS

Visceral sensation is found within which lobe?

the insular lobe

primary function of the parietal lobe

perception, processing sensory information. Contains primary somatosensory area, somatic sensation

primary functions of the occipital lobe

primary visual area

primary functions of the temporal lobe

auditory, olfactory, memory, understanding, and language

primary functions of the frontal lobe

executive functions, thinking, planning, organizing, problem solving, behavioral control. Contains primary motor area—VOLUNTARY movement

primary functions of the insular lobe

visceral sensation, gustatory cortex

The ______ is the primary voluntary motor area, and it is located within the ______ lobe.

pre-central gyrus; frontal lobe

What is the primary sensory area?

POST-central gyrus

Your patient is suffering from impaired coordination, frequent stumbling, and an unsteady gait. Following an MRI you find a large mass. Based on the given symptoms, what is most likely location of the mass?

cerebellum

major functions of the cerebellum

to fine tune motor activity; makes the activity precise

Where is the cerebellum located?

dorsally to the brainstem and connected via 3 cerebellar peduncles; and it has a R and L hemisphere.

What does the white matter in the cerebellum do?

white matter fiber tracts carry info TO and FROM the cerebellum

special characteristics of the cerebellum

cerebellar cortex (outer gray matter); arbor vitae (inner white matter), and cerebellar nuclei (deep collections of gray matter)

What structure acts as a major relay center for the nervous system and contains 7 nuclei that play a role in things like alertness and arousal?

thalamus

How many paired structures are in each hemisphere, and what are they all connected by?

1 in each hemisphere; they are connected by the intermediate mass of the thalamus

major functions of the thalamus

RELAY STATION for sensory information going INTO the cerebral cortex, ALL incoming sensory neuron axons (EXCEPT smell) project (synapse) onto neurons in the thalamus, neurons in the thalamus project to the cortex for integration. ALSO promotes alertness and wakefulness from sleep

How does the thalamus work as a relay station?

it is a relay station for the cerebellum neurons and basal ganglia (motor); neurons coming from the cerebellum and basal ganglia go through the thalamus before going to the cortex.

The facial nerve is responsible for which part of the tongue

taste on the anterior 2/3 of the tongue

The superior oblique muscle is paralyzed. Damaged to what cranial nerve is most likely responsible

trochlear nerve (IV)

Which cranial nerve carries motor info only?

hypoglossal (XII)

Which cranial nerve controls the lacrimal gland (responsible for tears)

Facial (VII)

Function of Cranial nerves (in order)

S=Sensory, M=Motor, B=Both; Some Say Marry Money, But My Brother Says Big Brains Matter More

function of olfactory nerve (I)

smell

function of optic nerve (II)

vision

function of oculomotor (III)

eye movement and pupil control

function of trochlear (IV)

eye movement (superior oblique of eye)

function of trigeminal (V)

sensation of face and anterior tongue, motor for muscle of mastication

function of abducens (VI)

eye movement (lateral rectus of eye)