A&P Exam 1

excitability, conductivity, and secretion

3 properties of neurons

long, extreme longevity, amitotic, and metabolism

neuron characteristics (4)

axon anterograde transport

away from cell body

axon retrograde transport

toward cell body

myelin sheath

increases speed of transmission, protein and lipid

CNS neuroglia (supporting cells)

oligodendrocytes, ependymal, microglial, and astrocytes

PNS neuroglia (supporting cells)

schwann and satellite cells

oligodendrocytes

form myelin sheaths

microglial cells

small macrophages

astrocytes

most abundant - maintain blood brain barrier, form structural support, alter synaptic activity, and regulate tissue fluid composition

ependymal cells

produce CSF

schwann cells (neurolemmocytes)

form myelin sheaths and assist in regeneration

satellite cells

provide insulation and regulate chemical environment

properties of MS

demyelination, oligodendrocytes attacked, myelin replaced by plaques, and nerve conduction distrupted

Guillain-Barré syndrome

loss of myelin and distal muscle weakness

sensory afferent, interneurons association, and motor efferent

neuron functional classes (by direction)

sensory (afferent) neurons

detect stimuli and transmit information towards CNS

Interneurons (association)

receive signals and carry out integrative function within CNS

motor (efferent) enurons

sends signals away from CNS

Multipolar neurons

1 axon and multiple dendrites, motor and interneurons

bipolar neurons

1 axon and 1 dendrite, special senses organs (retina, olfactory)

unipolar neurons

conduct impulses toward spinal cord, sensory neurons

anaxomic neurons

multiple dendrites and no axon, do not produce action potentials (brain, retina, and adrenal medulla)

3 connective tissues

meninges tissue type

cover and protect, enclose venous sinuses, contain CSF, and form partitions in the skull

function of meninges

Dura mater

outer meninges layer of fibrous connective tissue

Periosteal layer (dura)

attaches to inner surface of skull

Meningeal layer (dura)

outer covering of brain

Arachnoid mater

loose brain covering (middle layer)P

Pia mater

delicate connective tissue (inner layer), clings tightly to brain and spinal cord

subarachnoid space (between arachnoid and pia mater)

where CSF is located

L3-L5

location of lumbar tap

Action potential steps

RMP, threshold, depolarization, repolarization, hyperpolarization, and restoration

-70 mV

RMP voltage

RMP

leakage channels open, all gated channels closed, elctronegatve

sodium in, potassium out (leakage channel)

RMP in and out

-55 mV

voltage of threshold

depolarization

Sodium channels open, becomes more positive

repolarization

sodium channels inactive, and potassium channels open, become more negative

hyperpolarization

potassium continues to rush out longer than needed

-75 mV

voltage of hyperpolarization

restoration of RMP

sodium potassium pump restores NOKIA

neuronal synapse

nerve cell meets another nerve cell

neuromuscular synapse

nerve cell meets muscle ele

electrical synapse

communicate through gap junctions with connexons (proteins), faster

chemical synapse

communication through neurotransmitters, slower

acetylcholine, biogenic amines (monoamines), amino acids, and neuropeptides

4 classifications of neurotransmitters

acetylecholine

involved in skeletal muscle contractionsb

biogenic amines (monoamines)

catecholamines (dopamine) and indolamines (serotonin)

amino acids

glutamate, glycine, and GABA

neuropeptides

chains of amino acids including beta-endorphins and substance P

within a presynaptic neuron, calcium channel for release, and specific receptors

neurotransmitters properties and requirements

breakdown, reuptake, or diffuse away

3 ways to remove neurotransmitters

white matter

myelinated fiber in CNS

nuclei

Cluster of cell bodies in CNS

ganglia

cluster of cell bodies in PNS

Gyri

elevated ridges of tissue

Central sulcus

divides frontal and parietal lobes

Lateral sulcus

divides temporal and parietal lobes

Longitudinal fissure

separates cerebral hemispheres*

transverse cerebral fissure

separates cerebrum from cerebellum

frontal lobe

planning, inhibition, personality, problem solving, and IQ

afferent

away, carries sensory

parietal lobe

touch and proprioception

temporal lobe

hearing and smell

occipital lobe

vision

insula

taste

conscious control of precise and skilled voluntary movements of skeletal muscle, corticospinal tract

function of motor area in gray matter (cerebral cortex - frontal lobe)*

primary somatosensory cortex

function of sensory areas in gray matter (cerebral cortex - parietal lobe

planning, solving, speech, makes us who we are

function of association areas in gray matter (cerebral cortex)

motor functions

function of basal nuclei (white matter) in cerebrum

thalamus, hypothalamus, and epithalamus

Structures of diencephalon (gray matter)

gateway to cerebral cortex, afferent (sensory)

thalamus function

main visceral control center, maintains homeostasis

hypothalamus function

pineal gland secretes melatonin

epithalamus function

coordinates endocrine system

function of diencephalon deep brain

midbrain, pons, and medulla

3 structures of brain stem (superior to inferior)

connects cerebrum and spinal cord, 10 of cranial nerves

brain stem properties

motor movements, eye, auditory, and visual processing

midbrain function

control of breathing, respiratory rate

pons function

regulates heart rate, vasoconstriction, vasomotor center (BP), breathing (RR), and vomiting

medulla function

arbor vitae (tree of life - white matter), fibers are ipsilateral (same side of body)

cerebellum properties

smooth, coordinated movements, agility, posture, and equilibrium

cerebellum subconscious functions

thinking, language, and emotion

cerebellum cognitive functions

hippocampus, amygdala, cingulate gyrus

structures of limbic system - seat of emotion

response to perceived threats (fear/aggression)

amygdala function

expression of emotions through gestures, resolution fo mental conflicts

cingulate gyrus function

maintains cerebral cortical alertness/consciousness

RAS function (reticular activating system) (injury = coma)

choroid plexus

structure that produces CSF

septum pellucidum in between lateral ventricles, interventricular foramen to third ventricle, cerebral aqueduct to fourth ventricle, lateral and median aperture, subarachnoid space, dural venous sinuses

flow of CSF to subarachnoid space and dural venous sinuses

septum pellucidum in between lateral ventricles, interventricular foramen to third ventricle, cerebral aqueduct to fourth ventricle, central canal to spinal cord

flow of CSF to spinal cord

selects substances permitted to enter CSF from blood. maintains stable environment for brain

function of blood brain barrier

by tight junctions in capillaries that supply brain and spinal cord, least permeable capillaries in body

blood brain barrier formation

speech motor preparation and production, expressive aphasia

broca’s area function

speech organization and comprehension, receptive aphasia

Wenicke’s area function

brocas area, wernickes area, and basal nuclei (plus association areas)

structures that control language