midterm review (unit 1, 2, 3a, 3b) Flashcards
Define Physiology
the science of the FUNCTION of living systems
Function vs Process?
function: why
Process: how
The 7 steps in the response loop
stimulus, sensor, input signal, integrating center, output signal, target, response
feedforward control ______ change
anticipates
cells that respond to signals are
target cells
which feedback mechanism is not homeostatic?
positive feedback
what are the 3 forms of long range cell-cell communication?
endocrine, neural, neuro endocrine
lipophilic ligands interact with ______ receptor to produce a _____ response
intracellular, slower
water soluble ligands interact with ______ receptor to produce a _____ response
surface, faster
4 types of membrane receptors
ion channel, enzyme coupled receptor, G protein coupled receptor (GPCR), integrin receptor
what are the two types of second messenger molecules?
protein kinases, Ca 2+
cells can change their response to signals by changing _____ or _____
receptor number, sensitivity
molecule that activates the receptor but is not the native ligand
agonist
molecule that binds to the active site but does not activate
antagonist
GPCR is active when bound to ______ which _____ affinity to the beta gamma subunits
GTP, decreases
Cannon’s 4 postulates
nervous system has role in maintaining fitness of internal environment
some systems under tonic control
some systems under antagonistic control
one chemical signal can have different effects in different tissues
tonic control regulates parameters in a _______
up and down fashion
antagonistic control is characterized by
some neurons speeding up process and some neurons slowing down processes
cholera toxins _____ GTP ______
blocks
hydrolysis
a cell effected by cholera toxin will produce high levels of ______
cAMP
at 4 weeks the human brain is made of 4 regions, what are they?
Forebrain, midbrain, hindbrain, spinal cord
the forebrain is differentiated into these two regions
cerebrum, dienchephalon
the hindbrain is differentiated into these 3 regions
Medulla oblongata, cerebellum, pons
Name the three layers of meninges from innermost to outermost
Pia mater, arachnoid membrane, dura matter
where is cerebrospinal fluid produced?
In the choroid plexuses found within each of the 4 ventricles
How does CSF get into the subarachnoid space?
through apertures in the 4th ventrical
how does CSF escape the subarachnoid space?
through arachnoid villi that protrude into the dural sinus
what are two defining characteristics of CSF when compared to plasma?
CSF has very low protein and no blood cells
The presence of blood or protein in CSF indicates what?
infection
what creates the myelin sheath within the CNS?
oligodendrocytes
________ wrap around capillaries and secrete paracrine factors that promote tight junctions within the CNS
astrocytes
Dural sinus is also called s_________ sinus
superior sagittal sinus
three metabolic quirks of neural tissues
require a lot of oxygen
require a lot of glucose
require a lot of blood
the four sections of the spinal nerves
cervical, thoratic, lumbar, sacral
the sympathetic nerves on the spinal cord are located in a section for the spine called the _____
thoraco-lumbar division
definition of nuclei in the CNS
cluster of synapses
definition of tracts in the cns
bundle of axons
dorsal column transmit information about ________ towards the _______
touch, pressure, proprioception
brain
the spinothalamic tract transmits information about _____
pain, temperature, course touch
corticospinal tracts transmit information about ________
voluntary movement
the lateral corticospinal tract control the _____
the ventromedial corticospinal tract control the ______
limbs
trunk muscles
The midbrain is responsible for____
eye movement, visual and auditory reflexes
Pons are responsible for ____
relay station between cerebrum and cerebellum
medulla is responsible for _____
control of many involuntary functions, blood pressure, breathing, swallowing
medulla is the site of _____ for most neurons in the spinal tract
decussation (crossing over)
the cerebellum coordinates _____
movement
diencephalon has four structures
thalamus, pineal gland, hypothalamus, pituitary gland
what does the thalamus do?
relays and integrates sensory information
what does the hypothalamus do?
center for homeostasis
hunger, thirst, autonomic responses, endocrine systems
what does the pineal gland do?
secretes melatonin, involved in circadian rhythms
the four lobes of the cerebrum
frontal, occipital, parietal, temporal
the three regions of cerebral grey matter
basal ganglia, limbic system, cerebral cortex
primary motor cortex is located ____
in the frontal lobe, ridge just anterior to central sulcus
primary somatosensory cortex is located ________
in the parietal lobe, ridge just posterior to the central sulcus
dorsal columns in the spinal cord carry information about _____
fine touch, pressure, proprioception
spinocerebellar tract carry information about _____
proprioception (posture, coordination)
spinothalamic tract carry information about ____
pain and temp
corticospinal tract carry information about ____
voluntary movement
the lateral corticospinal tracts control the ____
limbs
a signal controlling the limbs will ____ in the medulla, follow the _____ corticospinal tract, and _____ in spinal grey matter
cross, lateral, not cross
a signal controlling the trunk will ____ in the medulla, follow the _____ corticospinal tract, and _____ in spinal grey matter
not cross, anterior, cross
5 steps of a spinal reflex
painful stimulus activates receptor
primary sensory neuron enters spinal cord
collateral activates ascending pathway for sensation (cc to brain)
withdrawal reflex
crossed extensor reflex
_____ substances require a channel to cross the blood brain barrier
hydrophilic / lipophobic
The four types of receptors
Chemo
Mechano
Photo
Thermo
definition of adequate stimulus
type of energy that a receptor responds best to
convergence of many primary neurons onto one secondary neuron increases _____ but decreases ______
sensitivity
resolution
Increased area in somatosensory cortex dedicated to the fingers rather than the arm is the caused by _______
lack of convergence in the fingertips
The two sensory pathways that do not undergo thalamic relay
olfactory pathway
equilibrium pathway
what is visceral sensory information?
gut, stomach, internal organs
How are sensations decoded in the CNS
MILD
Modality
Intensity
Location
Duration
What is modality determined by? what is another name for this type of decoding?
type of neuron activated (touch, photo…) and where the pathway terminates
also called labeled line coding
What is location determined by?
which receptive fields are activated
lateral inhibition enhances _____ and improves ________
contrast
stimulus localization
what is intensity determined by?
number of receptors activated
FREQUENCY of action potentials
what is duration determined by?
The length of time of the series of action potentials
type of receptor that turns off during a constant stimulus
phasic receptor
medulla crossing somatosensory pathways
fine touch, proprioception, vibration
spinal cord crossing somatosensory pathways
nociception, temperature, coarse touch
the superficial cutaneous sensory receptors and their adaptation
Merkel’s disk slow
Meissner’s corpuscle fast
the deep cutaneous sensory receptors and their adaptations
Ruffini’s corpuscle slow
Pacinian corpuscle fast
nociception is mediated by what types of channels?
Transient Receptor potential (TRP) channels
TRP channels do not have an adequate stimulus. Why?
mediated by a variety of sensations and non-selective ion channels
the reason wasabi tastes “hot”
The TRPV that is activated by wasabi is also activated by warm temperatures
nociception is mediated by what nerves?
free nerve endings with ion channels
three ways neural reflexes are classified
according to the effector
according to the integrating center
number of neurons in pathway
only _____ reflexes are monosynaptic
motor
skeletal muscle reflexes monitor ______, integrate in the ____, efferent pathway is _____ and the effectors are _____
proprioception, CNS, alpha motor neurons, extrafusal muscle fibers
proprioceptors sense….
changes in join movement, muscle length, muscle tension
muscle spindles monitor _____
muscle stretch
golgi tendon organs monitor
muscle tension
the ______ in the central region of intrafusal fibers are _____ and send signals to the ______
free nerve endings
tonically active 1a afferent neurons
spinal cord
1a afferent neurons will synapse in the spinal cord with ______ and ____
alpha motor neuron
inhibitory interneuron
inhibitory interneurons inhibit ________ muscles
antagonistic
alpha gamma coactivation occurs when the muscle is _______
contracting
the stretch reflex prevents over stretching by….
negative feedback loop of 1a afferent neurons synapsing with alpha motor neurons and causing contraction
compare muscle reflex with voluntary movement
muscle reflex
- integrated in spinal cord
- inherent and fast movement
-driven by external stimuli
voluntary movement
- integrated in cerebral cortex
- learned movements, can improve with practice
- driven by conscious processing
crossed extensor reflex purpose
support body weight as shift away from pain
olfactory receptor neurons are true ______ neurons, ______ every 60 days, are _______
bipolar
replaced
GPCR
the five basic tastes
sweet
sour
salty
bitter
umami
What tastes are transduced by GPCRs
sweet, umami, bitter
taste travels from primary gustatory neurons to _____ then _____ then ______
medulla, thalamus, gustatory cortex
pathway for sound. (6)
sound,
tympanic membrane,
inner ear bones,
oval window,
vestibular duct (perilymph),
round window
perilymph similar to ____
endolymph similar to ______
plasma
intracellular fluid
the hair cells in the organ of corti are associated with the _______ membrane
tectorial
the longest stereocilium in a hair cell is called
kinocilium
In the _________ hypothesis, pitch is determined by _______ of activated hair cells
Place code
the location
In the _______ hypothesis, pitch is determined by the __________ of action potentials
temporal code
frequency
What is the main problem with the temporal code hypothesis of pitch? How is this problem explained?
neurons cannot transmit at the rate of the frequencies humans can hear
multiple neurons with staggered rates carry the code, pooling the response to be the frequency we hear
_____ is determined by the amplitude of the action potential
volume
the tree types of hearing loss
conductive
central
sensorineural
conductive hearing loss is caused by _________________ and is usually _________
issues with earwax or fluid in middle ear
temporary
central hearing loss is caused by _______________
damage to neural pathway between ear and brain or damage to cortex
sensorineural hearing loss is caused by __________
damages to structures of the inner ear
equilibrium is detected in the ________ and the ______
otolith organs
semicircular canals
The semicircular canals detect ________ acceleration
rotational
each semicircular canal has an associated ______ which contains hair cells grouped in _____
ampulla
cristae
like the hair cells in the ear are embedded in the _________, the hair cells in ampulla are embedded in a ______
tectorial membrane
cupula
the kinocilium within cristae are much _____ than those within the organ of corti
larger/ more defined
the two otolith organs within the ear are called the _______ and the ______ which contains hair cells grouped in ______
utricle
saccule
maculae
the gelatinous membrane that hair cells are embedded into in maculae is called the ________
otolith membrane
equilibrium information goes to the _______ and the ______ in the neural pathway
cerebellum
medulla
The __________ is the region where optic nerve and blood vessels leave the eye
optic disk
which order is the neural pathway for vision?
a. optic tract
b. optic nerve
c. visual cortex
d. thalamic relay
e. optic chiasm
b. optic nerve
e. optic chiasm
a. optic tract
d. thalamic relay
c. visual cortex
The integrating center for a pupillary light reflex is the ______
midbrain
The parasympathetic light reflex causes ______ and innervates _____ smooth muscles
constriction
circular
The sympathetic light reflect causes ______ and innervates _____ smooth muscles
dilation
radial
does the light reflex information always cross the midline?
no, there are two options to cross (chiasm and midbrain) and sometimes the information does not cross
which cell mediates non-visual responses to light?
modified ganglion cells
why is the mammalian eye considered inverted?
The photoreceptors are farthest from the light source
which neuron in the eye defines the receptive field?
ganglion cell
what are three characteristics of the fovea?
all cone photo receptors
requires high levels of light
less convergence
Light causes retinal to be in the _____ conformation and ____ affinity of opsin
trans
decrease
in the dark cGMP levels are ____, channels are ___, membrane is _____
high
open
polarized (tonic)
in the light cGMP levels are _____, channels are _____, membrane is ______
low
closed
hyperpolarized
the color that a cone can recognize is based on ________, humans have _______ cone types
opsin concentration
three (red, blue, green)
