Lecture Slides 6, 7, 8, 9: Nervous System & Endocrine System (Midterm 2) Flashcards
What are the 2 main subdivisions of the nervous system?
–Central nervous system (CNS):
brain and spinal cord
–Peripheral nervous system (PNS):
sensory receptors and nerves
What is a sensory receptor?
ending of neurons or
separate, specialized cells that detect such things
as temperature, pain, touch, pressure, light,
sound, odors
What is a nerve?
a bundle of axons and their sheaths that
connects CNS to sensory receptors, muscles, and
glands
What is a ganglion?
collection of neuron cell bodies outside
CNS
What is a plexus?
extensive network of axons, and
sometimes neuron cell bodies, located outside
CNS
What are the 2 nerve types found in the PNS?
- Sensory (afferent):
transmits action
potentials from receptors
to CNS. - Motor (efferent):
transmits action
potentials from CNS to
effectors (muscles,
glands)
What are the 2 subdivisions of the PNS’ Motor Division
Somatic Nervous System, and Autonomic Nervous System
what does the somatic nervous system do?
Controls skeletal muscles, conscious thought, and is a SINGLE neuron system.
What are the 3 divisions of the ANS, Autonomic Nervous System?
Sympathetic, Parasympathetic, and Enteric.
What does the Autonomic Nervous System do?
– Subconscious or involuntary control.
– Two neuron system: first from CNS to ganglion; second from ganglion to
effector.
What does the sympathetic nervous system do?
Prepares the body for movement, this is out fight or flight system
what does the parasympathetic nervous system do?
Regulates resting or vegetative functions such as
digesting food or emptying of the urinary bladder.
What does the enteric nervous system do?
plexuses within the wall of the digestive tract. Can control the digestive tract independently of the CNS, but still considered part of ANS because of the parasympathetic and sympathetic neurons that
contribute to the plexi.
What is a Neuron?
Neurons or nerve cells
receive stimuli and
transmit action
potentials
– Organization
* Cell body or soma
* Dendrites: input
* Axons: output
what is a Neuroglia?
Neuroglia or glial cells
– Support and protect
neurons
What makes up the cell body of a neuron?
Cell Body. Nucleus, Nissl Bodies.
– Nissl bodies = rough E.R: primary site
of protein synthesis.
What part of a dendrite interfaces with axons?
Dendritic spines
what happens at a synaptic terminals?
electrical signal gets converted to a chemical message
where is the trigger zone on an neuron?
at the axon hillock is where action potentials are generated.
what fluid fills the inner space of an axon
axoplasm, which carries nutrients in the cell, or viruses like herpes to the CNS
afferent is?
sensory, toward CNS
efferent is?
motor, away from CNS
interneurons or association neurons are?
within CNS or move signals from one neuron to another
most neurons in CNS, and all motor neurons are…
multipolar
where can bipolar neurons be found?
as sensory in the retina and the nose
what are unipolar cells?
cell bodies with a single dendrite-like periphery. Found in invertebrates
what does an astrocyte do?
forms the blood-brain barrier
what do ependymal cells do?
forms choroid plexus, which secretes cerebrospinal fluid. The cilia on its surface move CSF thru the brain.
what do microglia do?
phagocytize dead or foreign tissue, immune function in CNS. Macrophage
what do oligodendrocytes?
form myelin sheaths, found in CNS
what are schwann cells? (neurolemmocytes)
wraps axons to create myelin sheath. found in PNS
12 cranial nerves? o o o t t a f v g v a h & ssmmbmbsbbmm
olfactory - smell
optic - vision
oculomotor - eye motor
trochlear - motor to superior oblique muscle of eye
trigeminal - sensory in jaw
abducens - motor to lateral rectus muscle of eye
facial - motor to facial muscles
vestibulocochlear - hearing and balance
glossopharyngeal - sensory to inner throat
vagus - voice control
hypoglossal - motor to tongue
accessory - motor to sternocleidomastoid and traps
function of cerebellum
motion, balance, posture
function of cerebrum
thought, control of muscle
function of superior colliculi
visual reflex, receives info from inferior colliculi
function of inferior colliculi
hearing
function of cerebellar peduncles
has superior, middle, and inferior peduncles that communicate with brainstem parts: midbrain, pons, medulla oblongata
what are purkinje cells
high functioning neurons capable of 200,000 synapses a second
function of floculonodular lobe
balance and eye movement
function of vermis
fine motor control
function of lateral hemispheres of cerebellum
complex movements, works with cerebrum
function of pineal gland
causes sleepiness, regulates biological clock
function of habenular nucleus, in epithalamus
response to odor
what are mammilary bodies
bulges on anterior of hypothalamus, response to odor
function of infundibulum
controls endocrine system, connects hypothalamus to posterior pituitary
precentral gyrus is
primary motor cortex
postcentral gyrus is
primary somatic sensory cortex
function of frontal lobe
motor function, motivation, aggression, smell, mood
function of parietal lobe
sensory info, except smell, hearing vision
function of occipital lobe
reception and integration of visual input
function of temporal lobe
sensory info for smell, hearing. Memory, abstract thought. Insula is within
function of basal nuclei
motor function
what are nuclei in the cerebrum called
corpus striatum
function of limbic system
survival needs, emotion
what type of fluid is in the subdural space
serous fluid
what type of fluid is in the subarachnoid space
CSF
where are the venous sinuses found
in the dura mater deep folds, falx… tentorium
function of CSF
provides cushion, and nutrients to CNS
what is the circle of willis
combo of internal carotid and vertebral arteries, prevents loss of circulation in brain
what regulates secretions of the pituitary gland
hypothalamus
where are neurohormones secreted
posterior petuitary
what hormones are released from anterior pituitary
–GHRH. Growth hormone-releasing hormone. Causes the anterior pituitary to release growth hormone.
–TRH. Thyroid-releasing hormone. Causes the anterior pituitary to release thyroid-stimulating hormone (TSH).
–CRH. Corticotropin-releasing hormone. Causes anterior pituitary to produce adrenocorticotropic hormone.
–GnRH. Gonadotropin-releasing hormone. Causes anterior pituitary to produce FSH (follicle stimulating hormone) and LH (luteinizing hormone).
–PRH. Prolactin-releasing hormone. Causes the anterior pituitary to release prolactin.
*Inhibiting hormones:
–GHIH. Growth hormone-inhibiting hormone, somatostatin. Causes the anterior pituitary to decrease release of growth hormone.
–PIH. Prolactin-inhibiting hormone. Causes the anterior pituitary to decrease release of prolactin.
what hormones are released from posterior pituitary
ADH antidiuretic hormone - regulates blood pressure + water retention
hormones of the thyroid gland are…
T3, T4 which affect metabolism rate and temperature
where is calcitonin secreted
parafollicular cells in the thyroid gland
what does calcitonin do
decreases calcium concentration in bloodstream, bone growth
function of parathyroid
increases blood calcium concentration, bone breakdown
function of adrenal glands
secretes epinephrine and norepinephrine, prepares body for fight & flight
hormones of adrenal cortex
*Mineralocorticoids: Zona glomerulosa–Aldosterone produced in greatest amounts. Increases rate of sodium reabsorption by kidneys increasing sodium blood levels
*Glucocorticoids: Zona fasciculata–Cortisol is major hormone. Increases fat and protein breakdown, increases glucose synthesis, decreases inflammatory response
*Androgens: Zona reticularis–Weak androgens secreted then converted to testosterone by peripheral tissues. Stimulate pubic and axillary hair growth and sexual drive in females
function of pancreas
releases digestive enzymes to small intestine, as well as glucagon, insulin, and somatostatin
insulin function
increase uptake of glucose and amino acids by cells
glucagon function
causes breakdown of glycogen and fats for energy
where are tears produced
lacriminal gland
function of puncta
collects tears
function of lacriminal canaliculi
collects tears from puncta
function of sclera
maintains eye shape, muscle attachment points, dense collagenous connective tissue with elastic fibres
function of cornea
collagen, elastic fibers, proteoglycans. allows light to enter eye, bends and refracts light.
what is the middle layer of the eye
vascular tunic
function of iris
colored, controls light entering the pupil, smooth muscles: sphincter pupillae & dilator pupillae
function of ciliary body in eye
produces aqueous humor that fills anterior chamber
what do ciliary muscles do
control shape of the lens, when relaxed the lens in more convex
what is the small yellow spot in the eye called
macula lutea
function of fovea centralis
tightly packed photoreceptor cells
function of optic disc
blind spot. blood vessels and nerves pathway in eye
function of anterior compartments (anterior and posterior chambers)
ocular pressure via aqueous humor, refracts light
function of posterior compartment
ocular pressure, filled with vitreous humor, holds lens and retina in place
what is emmetropia
resting position of lens, ciliary muscle is relaxed and lens is flat
what is the ear called
auricle
function of tympanic membrane
separates external and middle ears
what holds the stapes in place
annular ligament
what are the ear follicles called
stereocilia, which release potassium when triggered
how do we hear
- Sound waves strike the
tympanic membrane and
cause it to vibrate. - Vibration of the tympanic
membrane causes the three
bones of the middle ear to
vibrate. - The foot plate of the stapes
vibrates in the oval window. - Vibration of the foot plate
causes the perilymph in the
scala vestibuli to vibrate. - Vibration of the perilymph
causes displacement of the
basilar membrane. Short
waves (high pitch) cause
displacement of the basilar
membrane near the oval
window, and longer waves
(low pitch) cause
displacement of the basilar
membrane some distance
from the oval window.
Movement of the basilar
membrane is detected in the
hair cells of the spiral organ,
which are attached to the
basilar membrane - Vibrations of the
perilymph in the scala
vestibuli and of the
endolymph in the
cochlear duct are
transferred to the
perilymph of the scala
tympani. - Vibrations in the
perilymph of the scala
tympani are transferred
to the round window,
where they are
dampened.
what is an attenuation reflex
muscles contract during loud noises to prevent damage
what evaluates head POSITION and ACCELERATION
utricle and saccule of the vestibule
what evaluates head 3D movement
semicircular canals, sagittal, coronal, transverse
what are otoliths
small masses in the macula of the utricle and saccule. They detect head position or acceleration due to gravity, with the help of stereocilia and one kinocilium. Static labyrinth
what fills the kinetic labyrinth
endolymph
the base of each semicircular canal is expanded into a
ampulla
what are cupula
floats in semicircular canals in the kinetic labyrinth, displaced by endolymph to create sense of balance
