Unit 3 Test Flashcards
Ch 8, 9, and 10
Neurons and Neural tissue
2 kinds of cells that make up the nervous system p 194
central nervous system
brain and spinal cord p 193
peripheral nervous system
all nerves and ganglia (all nervous tissue) outside the CNS p 193
sensory (afferent) division
conducts action potentials from sensory receptors to the CNS p 193
motor (efferent) nervous system
conducts action potential away from the CNS to effector organs such as muscles and glands p 193
somatic nervous system
transmits action potentials from the CNS to skeletal muscles p 193
autonomic nervous system
transmits action potentials from the CNS to cardiac muscle, smooth muscle, and glands p 194
enteric nervous system
unique subdivision of the peripheral nervous system which has both sensory and motor neurons contained wholly within the digestive tract. It can function without input from the CNS or PNS, but is normally integrated. p 194
cell body
contains nucleus, extensive rough ER, golgi apparatus, mitochondria. large numbers of neurofilaments (intermediate) and microtubules organize the cytoplasm into distinct areas. p 194
dendrites
short, highly branching cytoplasmic extensions tapered from their base at the neuron cell body to their tips. usually receive information from other neurons or sensory receptors and transmit the information toward the cell body p 194
axons
single long cell process extending from the cell body, has a uniform diameter and can be a few mm to more than a meter long
Axons of sensory neurons conduct action potentials towards the CNS, and axons of motor neurons conduct action potentials away from the CNS
May be unbranched or branch to form collateral axons p 194
axon hillock
where the axon leaves the cell body p 194
multipolar neurons
many dendrites and an axon p 195
bipolar neurons
one dendrite and an axon, in sensory organs like retina and nasal cavity. p 195
pseudo-unipolar neurons
appears to have an axon and no dendrites, located in most sensory organs p 195
neurolgia
non neural cells, more numerous than neurons, retain ability to divide p 195
astrocytes
major supporting cells in CNS, provide structure regulate neural signaling contribute to blood brain barrier help repair neural tissue p 195
microglia
small mobile cells that protect CNS from infection, phagocytic in response to inflammation p 195
oligodendrocytes
form myelin sheaths around axons or enclose unmyelinated axons in CNS p 195
Schwann cells
form myelin sheaths around axons or enclose unmyelinated axons in PNS p 195
satellite cells
?? look at PPT
myelined axons
have sheaths of oligodendrocytes or Schwann cells wrapped around them increases speed and efficiency of the action potentials along the axon p 197
unmyelined axons
rest in indentations of oligodendrocytes or Schwann cells p 197
Nodes of Ranvier
gaps the the myelin sheath between oligodendrocytes or Swann cells p 197
gray matter
groups of cell bodies and dendrites where there is little myelin p 197
white matter.
bundles of parallel axon with their myelin sheaths p 197
nerve tracts
conduction pathways formed by white matter of the CNS which propagate action potentials from one area of the CNS to another p 197
ganglion
in the PNS a cluster of neuron cell bodies p 197
nerves
bundles of axons and their connective tissue in the PNS p 197
resting membrane potential
the uneven charge distribution in a restin/unstimulated cell p 197
polarized
uneven distribution of charge across the cell membrane p 197
leakage channels
always open for ions to leak across the membrane down their concentration gradient p 197
gated channels
closed until opened by specific signals p 197
chemically gated channels
opened by neurotransmitters or other chemicals p 198
voltage gated channels
opened by a change in membrane potential p 198
blood-brain barrier
astrocytes participate with blood vessel endothelium to form a barrier between blood and the CNS p 195
ependymal cells
line fluid filled cavities in the CNS, some produce cerebrospinal fluid and others have cilia that move cerebrospinal fluid through the CNS p 195
sodium potassium pump
compensates for the constant leakage of ions across the membrane–maintains greater concentration of Na+ outside the cell and K+ inside, consumes 70% of the ATP in a neuron p 198
excitable cells
resting membrane potential changes in response to a stimulus that activates gated ion channels, muscle and nerve cells p 198
local current
movement of Na+ through chemically gated channels p 199
depolarization
local current causes the inside of the cell membrane to become positive p 199
local potential
depolarization results in local potential p 199
threshhold
large enough local potential to cause voltage gated channels to open, most often at the axon hillock p 200
action potential
depolarization and repolarization p 200
Hyperpolarization
at the end of repolarization the charge briefly becomes more negative than the resting potential p 200
All-of-none
if the threshold is reached, and action potential occurs, if not then no action potential occurs p 200
Continuous conduction
in unmyelinated axons the action potential in one part of a cell membrane stimulates local currents in adjacent parts of the cell membrane. Those local currents in the adjacent membrane produce an action potential. The action potential is conducted along the entire axon p 200
Salutatory conduction
in myelinated axons the action potential at one node of Ranvier causes local current to flow through the extracellular fluid and through the cytoplasm of the axon to the next node, stimulating an action potential at the next node. Action potentials jump from one node to the next. It increases conduction velocity p 200
Synapse
a junction where the axon of one neuron interacts with another neuron or with the cells of an effector neuron p 200
Presynaptic terminal
end of axon
Postsynaptic membrane
membrane of the dendrite or the effector cell
Neurotransmitters
chemical
Synaptic cleft
space separating presynaptic and postsynaptic membranes
Synaptic vesicles
stores neurotransmitters in presynaptic terminal
Acetylcholine (Ach)
neurotransmitter
Norepinephrine
neurotransmitter
Acetylcholinesterace
enzyme breaks down neurotransmitter
Describe the continuous conduction of an action potential in an unmyelinated axon.
.
Describe the saltatory conduction of an action potential in a myelinated axon.
.
Describe the factors that contribute to the generation of the resting membrane potential.
.
Describe the action of the sodium-potassium pump.
.
Describe how a voltage gated channel works.
.
Describe how a voltage gated channel produces an action potential.
.
Describe what happens if a local potential doesn’t meet the threshold value.
.
Describe what happens if a local potential meets the threshold value.
.
Describe several characteristics of neuroglia cells.
.
Compare and contrast astrocytes and satellite cells.
.
Compare and contrast oligodendrocytes and Schwann cells.
.
Name the categories of the spinal nerves (regional terms).
???cervical nerves C1 to C4
thoracic nerves C5 to T1
lumbar nerves L1 to S4
p
reflex
involuntary reaction in response to a stimulus applied to the periphery and transmitted to the CNS p 203
reflex arc
the neuronal pathway by which a reflex occurs. it is the basic functional unit of the nervous system because it is the smallest, simplest pathway capable of receiving a stimulus and yielding a response p 202
sensory receptor
basic component of a reflex arc 1 p 202
sensory neuron
basic component of a reflex arc 2 p 202
interneuron
basic component of a reflex arc 3, but not in all p 202
motor neuron
basic component of a reflex arc 4
effector neuron
basic component of a reflex arc 5
converging pathway
2 or more neurons synapse with the same neuron p 204
diverging pathway
the axon from one neuron divides and synapses with more than one other neuron p 204
summation
allows integration of multiple subthreshold signals to bring the membrane potential to threshold and trigger an action potential. p 204
spatial summation
occurs when the local potentials originate from different locations on the postsynaptic neuron p 204
temporal summation
occurs when local potentials overlap in time, can occur from a single input that fires rapidly p 204
spinal cord
extends from foramen magnum at the base of the skull to the second lumbar vertebra. p 205
cauda equine
nerves exiting the inferior end of the spinal cord resemble a horse’s tail p 205
dorsal column
myelinated axons posterior
ventral column
myelinated axons anterior
lateral column
myelinated axons sides
ascending tracts
conduct action potentials toward the brain
descending tracts
conduct action potentials away from brain
anterior horn
gray matter
laternal horns
gray matter
posterior horn
gray matter
ventral root
ventral rootlets combine to form
dorsal root
dorsal rootlets combine to form
dorsal root ganglion
call bodies of pseudo-unipolar sensory neurons p 205
stretch reflex
muscles contract in response to a stretching force p 207
knee-jerk reflex
classic example of stretch reflex
withdrawal reflex
remove a limb or another body part from a painful stimulus p 207
spinal nerves
arise along the spinal cord from the union of dorsal and ventral roots.
mixed nerves
spinal nerves contain axons of both sensory and somatic motor neurons
plexuses
spinal nerves are organized into 3 major plexuses where nerves come together then separate
cervical plexus
c1 to c4, innervate the hyoid bone, skin of the neck and posterior portion of the head
phrenic nerve
most important nerve of the cervical plexus, innervates the diaphragm p 207
brachial plexus
c5 to t1, 5 major nerves to the upper limbs and shoulders
axillary nerve
2 shoulder muscles and skin over shoulder
radial nerve
all muscles in the posterior arm and forearm as well as skin over posterior arm, forearm, and hand
musculocutaneous nerve
anterior muscles of arm and the skin over the radial surface of the forearm
ulnar nerve
2 anterior forearm muscles and most of the intrinsic hand muscles. Also the skin over the ulnar side of the hand. passes behind the elbow–funny bone p 209
median nerve
most of the anterior forearm muscles and some intrinsic hand muscles, skin over the radial side of the hand
lumbosacral plexus
l1 to s4, 4 major nerves to the lower limbs
obturator nerve
muscles of the medial thigh and skin over medial thigh
femoral nerve
anterior thigh muscles and skin over anterior thigh and medial side of leg
tibial nerve
posterior thigh muscles anterior and posterior leg muscles and most intrinsic foot muscles, and skin over the sole of the foot
common fibular nerve
muscles of lateral thigh and leg and some intrinsic foot muscles. skin over the anterior and lateral leg and the dorsal surface (top) of the foot
sciatic nerve
tibial and common fibular nerves are bound together with a connective sheath
Brainstem
connects spinal cord to the remainder of the brain. Consists of the medulla oblongata, pons, and the midbrain. contains nuclei involved in vital functions like heart rate, blood pressure and breathing. nuclei for all but the first 2 cranial nerves p 210
Medulla oblongata
most inferior portion of the brainstem and is contiguous with the spinal cord. contains discrete nuclei that regulate heart rate, blood vessel diameter, breathing, swallowing, vomiting, coughing, sneezing, balance and coordination. p 210
Pyramids
2 prominent enlargements on the anterior surface that extend the length of the medulla oblongata. nerve tracts which transmit action potentials from the brain to the motor neurons of the spinal cord and are involved in the conscious control of skeletal muscles p 211
Pons
immediately above the medulla oblongata contains ascending and descending nerve tracts as well as several nuclei functional bridge between cerebrum and cerebellum. controls chewing and salivation as well as sharing breathing swallowing and balance with the medulla oblongata. p 211
Midbrain
over the pons, smallest region of the brainstem
Colliculi
4 mound son midbrain, relay centers for auditory pathways and visual reflexes and receive touch and auditory input p 211
Substantia nigra
black nuclear mass controls general body movements
Reticular formation
scattered throughout the brainstem regulates cyclical motor functions like respiration, walking, chewing p 211
Activating system
plays a major role in arousing and maintaining consciousness and regulating sleep p 212
Cerebellum
rear brain
Cerebellar peduncles
attaches cerebellum to brainstem. provide routes of communication between cerebellum and other parts of CNS p 212
Diencephalon
between brainstem and cerebrum, thal, epithal, and hypothal
Thalamus
cluster of nuclei, influences mood and registers pain
Epithalamus
over and behind thalamus, response to doers
Hypothalamus
lowest, maintains homeostasis, body temp, hunger thirst,
Cerebrum
largest part of brain
Longitudinal fissure
divides left and right hemispheres of cerebrum p 213
Gyri
folds/ridges
Sulci
valleys
Frontal lobal
vol motor functions, motivation, aggression, mood, smell p 213
Parietal loba
receiving and consciously perceiving senses
Occipital love
receiving and perceiving visual input
Central sulcus
separates frontal and parietal lobes
Temporal lobe
olfactory and auditory, plays important role in memory, abstract thought and judgement p 214
Lateral fissue
separates temporal lobe from rest of cerebrum
Insula (5th lobe)
deep w/in lateral fissure
Ascending tracts
transmits action potentials from periphery to brain p 214
Spinothalamic tract
xmits action potentials dealing with pain and temp to the thalamus to the cerebral cortex, example of ascending tract p 214
Dorsal tract
xmits action potentials dealing with touch, position, and pressure, ascending tract
Primary sensory areas
where sensations are perceived
Primary somatic areas
general sensory area
Association areas
cortical areas involved in recognition
Voluntary movements
consciously activated to achieve a goal
Upper motor neurons
result in vol movements and connect to lower motor neurons
Lower motor neurons
in anterior horn or cranial nerve nuclei
Primary motor cortex
control voluntary movements of skeletal muscles
Premotor area
where motor functions are organized before they are actually initiated in the primary motor cortex
Lateral coritcospinal tracts
control speed and precision of skilled movements of the hands
Basal nuclei
group of functionally related nuclei
Corpus stiatum
located deep in the cerebrum
Substantia nigra
dark pigmented cells in the midbrain
Comparator
sensing device that compares data from 2 sources
Proprioceptive neruons
innervate joints tendons muscles and provides info about position of body parts
Commissures
sensory info shared between hemispheres
Corpus callosum
largest commissure
Sensory speech area
Wernicke area parietal lobe area of speech
Motor speech area
Broca area inferior frontal lobe
Aphasia
absent of defective speech or language comprehension
Electroencephalogram
brain’s electrical activity
Brain waves
wavelike patterns
Alpha waves
quiet resting state
Beta waves
intense mental activity and beginning of sleep
Delta waves
deep sleep
Theta waves
children
Working memory
task associated memory
Short-term memory
retained for a few min or a few days
Long-term memory
stored for a few min or permanent
Condolidation
gradual process of memory, formation of new and stronger synaptic connections
Procedural memory
dev of new motor skills
Memory engrams
long term memory retention
Limbic system
long-tern declarative memory, emotions, visceral responses to emotions motivations and mood. olfactory nerves.
Meninges
3 connective tissue membranes
Dura mater
most superficial and thickest
Epidural space
between dura mater and vertebrae
Anesthesia
injection
Arachnoid mater
second meningeal membrane
Dural space
potential space containing a very small amount of serous fluid
Spinal block
anesthetic
Spinal tap
sample of cerebrospinal fluid
Pia mater
third meningeal membrane
Subarachnoid space
between arachnoid major and pia major
Ventricles
CNS fluid filled cavities
Lateral ventrical
each cerebral hemisphere has a relatively large cavity
Third ventricle
smaller midline cavity in center of diencephalon
Fourth ventricle
base od cerebellum and connected to the 3d ventricle by a narrow canal
Cerebral aqueduct
narrow canal between 3d and 4th ventricle
Cerebrospinal fluid (CSF)
bathes brain and spinal cord, provides protective cushion around CNS
Choroid plexuses
specialized structures made of ependymal cells, located in ventricles p 223
Arachnoid granulations
masses of arachnoid tissue penetrate the superior saggital sinus, a dural venous sinus in the longitudinal fissure and CSF passes from the subarachnoid space into the blood through these granulations p 223
Hydrocephalus
blockage of openings cause CSF to accumulate in ventricles
Cranial nerves
12 pairs
Autonomic nervous system
controlled unconsciously
Preganglionic neurons
first
Postganglionic neurons
second
Autonomic ganglia
outside the CNS
Parasympathetic division
rest and Digest
Fight-or-flight
sympathetic
Sympathetic division
fight or flight
Sympathetic chain ganglia
connected to one another and form a chain along both sides of the spinal cord
Collateral ganglia
located nearer target organs, celiac, superior mesenteric ganglia
Splanchnic nerves
sympathetic nerves that extend to collateral ganglia in the abdominal and pelvic region
Terminal ganglia
located in effector organs in the head or embedded in effector organs in thorax abdomen and pelvis
Achetylcholine
neurotransmitter of sympathetic and parasympathetic neurons p 228
Norepinephrine
neurotransmitter of post ganglionic neurons
Enteric nervous system (ENS)
plexuses within the wall of the digestive tract
Describe the symptoms of stroke.
headache, loss of motor skill, weakness, confusion, difficulty speech and swallowing, vision, confusion, seizures
Describe several treatments for stroke.
restore blood flow, hypertension meds, physical and speech therapyp 231
What are some of the effects of aging on the nervous system?
gradually declines, number of sensory neurons, reflexes slow, homeostasis, loss of motor control, short term memory, sleep is more difficult
Select one condition from each category on page 232 and describe it.
MS, autoimmune condition initiated by viral infection, inflammation of brain and spinal cord, demyelination. exaggerated reflexes, tremors and speech defects
Special Senses
specialized
receptors
nerve endings capable of responding to stimuli
mechanoreceptors
bending or stretching
chemoreceptors
odor
photoreceptors
light
thermoreceptors
temp
nociceptors
pain
Merkel disks
small superficial nerve endings involved in detecting light, touch, and superficial nerve endings
Meissner corpuscles
receptors for fine, dicriminating touch
Ruffini corpuscles
detecting continuous pressure
Pacinian corpuscles
deep pressure, vibration and position p 239
pain
unpleasant perceptual and emotional experiences, localized sharp, diffuse burning or aching
referred pain
originate in a region of the body that is not the source of pain
olfaction
smell
odorants
airborne molecules
olfactory bulb
9
olfactory tracts
9
adaptation
decreased sensitivity after time
taste buds
oval structures that detect taste
papillae
enlargements on the surface of the tongue
taste cells
40
taste hairs
hairlike processes that extend into a tiny opening
taste pore
tiny opening in the surrounding epithelium
conjunctiva
thin transparent mucous membrane covering the inner surface of the eyelid
lacrimal apparatus
lacrimal gland in the superior lateral corner of the orbit
lacrimal gland
produces tears
lacrimal canaluculi
small ducts
lacrimal sac
enlargement of the nasolacrimal duct
nasolacrimal duct
opens into the nasal cavity
extrinsic eye muscles
6, movement of eye
rectus muscles
attach to 4 quadrants of eye
oblique muscles
angle to long axis of eye
fibrous tunic
outer tunic, sclera and cornea
vascular tunic
middle tunic, choroid, ciliary body, iris
nervous tunic
innermost tunic, retina
sclera
firm white outer connective tissue layer, maintains shape protects internal structures and provides attachment sites for muscles
cornea
transparent permits light to enter
Ciliary body
contains smooth muscles
lens
flexible biconvex transparent disk
pupil
opening
iris
colored part of eye
retina
posterior 5/6 of eye
rods
photo receptor cells, low light
cones
photo receptor cells, color vision
rhodopsin
photosensitive pigment
opsin
colorless protein
retinal
yellow pigment
optic nerve
axons converge at the posterior of the eye
macula
small spot near the center of the posterior retina
fovea centralis
part of the retina where light is most focused
blind spot
optic disk contains no photoreceptor cells
anterior chamer
between cornea and lens front of iris
posterior chamber
between cornea and lens back of iris
vitreous humor
transparent jelly substance in vitreous chamber
aqueous humor
watery fluid in anterior and posterior chamber
focal point
crossing point of light rays
focusing
light converges
accommodation
muscles reshape lens and focus
optic chiasm
where 2 optic nerves connect to each other
visual field (of eye)
image seen by each eye
color blindness
absence of perception of one or more colors
auricle
external ear
external auditory meatus
9
external auditory canal
passageway that leads to eardrum
ceruminous glands
produce cerumen
cerumen
modified sebum/earwax
tympanic membrane
thin membrane that separates ext ear from middle ear
oval window
opening in medial side of middle ear
round window
opening in medial side of middle ear
auditory ossicles
3 bones in inner ear
malleus
hammer
incus
anvil
stapes
stirrup
auditory tube
opens into pharynx and enables air pressure equalized between outside air and middle ear
bony labyrinth
tunnels and chambers in temporal bone
membraneous labyrinth
membranous tunnels and chambers
endolymph
clear liquid in membranous labyrinth
perilymph
liquid in space between membranous and and bony labyrinth
cochlea
snail shell with bony core p 252
spiral organ (organ of Corti)
contains specialized sensory cells
static equilibrium
position of head relative to gravity
dynamic equilibrium
change of direction and head movements
vestibule
inner ear, 2 chambers
utricle
chamber in vestibule
saccule
chamber in vestibule
maculae
specialized patches of epithelium
otoliths
particles composed of protein and calcium carbonate, bends hair cell microvili and initiating action potentials
semicircular canals
dynamic equillibrium, right angles
ampulla
base of each semicircular canal
crista ampullaris
ridge of epithelium with a curved gelatinous mass
cupula
gelatinous mass
motion sickness
continuous stimulation of the semicircular canal
Describe how visual stimuli is converted into sight
9
Describe how sound waves are converted into hearing
9
Describe how odorants are converted into a sense of smell
9
Describe how food molecules are converted into a sense of taste
9
autocrine
stimulates cell that secretes it, white blood cells
paracrine
act locally, histamine
endocrine
in blood–act on distand cell
neurotransmitters
activate an adjacent cell, neuron on neuron, muscle, or gland cell
hormones
chemical messengers
humoral stimuli
blood borne molecules can stimulate release of some hormones
parathyroid hormone
10
antidiuretic hormone
10
neural stimuli
10
epinephrine/norepinephrine
10
releasing hormones
10
hormonal stimuli
10
tropic hormones
10
inhibition
10
inhibiting hormones
10
negative feedback
10
positive feedback
10
receptors
10
nuclear receptors
10
hormone response elements
10
transcription factors
10
G-protein
10
adenylate cyclase
10
protein kinases
10
amplification
10
cAMP
10
pituitary gland
10
hypothalamus
10
infundibulum
10
anterior pituitary
10
posterior pituitary
10
growth hormone
10
insulin-like growth factors (IGFs)
10
thyroid-stimulating hormone
10
adrenocortiocottropic hormone
10
cortisol
10
gonadotropins
10
lutenizing hormone
10
interstitial cell-stimulating hormone
10
follicle-stimulating hormone
10
prolactin
10
melanocyte-stimulating hormone
10
oxytocin
10
thyroid gland
10
hypterthyroidism
10
Graves disease
10
thyroxine
10
triiodothyronine
10
calcitonin
10
parathyroid glands
10
parathyroid hormones
10
hyperparathyroidism
10
hypoparathyroidism
10
adrenal glands
10
adrenal medulla
10
adrenal cortex
10
fight-or-flight response
10
aldosterone
10
renin
10
androgens
10
Pancreatic islets (islets of Langerhans)
10
Diabetes mellitus
10
hyperglycemia
10
testes/ovaries
10
estrogen
10
progesterone
10
testosterone
10
thymus
10
pineal gland
10
melatonin
10
What are the functions of the endocrine system?
10 functions–metabolism, food and digestion, tissue dev, ion regulation, water balance, heart rate and BP, blood glucose and nutrients, reproduction, uterine contraction and milk, immune syst
How are lipid-soluble hormones transported?
small size, not soluble, attach to binding proteins, long life span
How are water-soluble hormones transported?
dissolve in blood and circulate freely, diffuse into tissue–not capillaries, large, short life
To what kind of receptors do lipid-soluble hormones bind?
nuclear receptors and interacts with DNA
To what kind of receptors do water-soluble hormones bind?
membrane bound receptors to initiate response within cell
Describe how a G-protein receptor system works.
- hormone binds to receptor
- receptor changes shape and g protein binds to it, GTP replaces GDP on alpha subunit
- g protein separates and alpha unit separates from protein. GTP linked subunit activates cell response
- hormone separates from receptor phosphate is removes and GTP becomes GDP
In what way do hormones control the anterior pituitary?
releasing or inhibiting hormones
What is the hypothalamic-pituitary portal system?
capillary beds and veins that transport releasing and inhibiting hormones p 272
How does the hypothalamus control the posterior pituitary?
??? pass through hypothal-pituitary gland p 275
