exam 1- cell physiology and neurophysiology Flashcards
why do we develop illness or disease?
our body loses STABILITY via insults such as chemicals, toxins, bacteria, viruses, physical damages
what is physiology
the study of how living organisms work (the function, the why/how). it is an integrated science
closed loop mechanism components
variable, sensor, integrating center, effector
variable
the factor that is being regulated. this can be body temp, for example. if it changes beyond the set point, or what is considered to be “normal,” your body will sense that. hence the next step being the sensor
sensor
(sensory neuron). this is the receptor. the sensor senses changes in the variable
afferent pathway
“INto INtegrating center” the afferent pathway goes from the sensor to the integrating center (control center)
integrating center
aka the control center, central nervous system. the control center can make a decision to adjust your bodily function to bring the variable back to the set point. this decision becomes a COMMAND, hence command center
efferent pathway
“Efferent Exiting” the efferent pathway goes from the control center to the effector
effector
the workers. they will do everything necessary in response to the command regarding the variable. this is where the changes are made
homeostasis
dynamic internal consistency
negative feedback
negative feedback is employed to reinforce the parameters. if the variable gets too high, it will go back down (neg. feedback) to reinstate the balance within the parameter. If it gets too low, it will rise. neg feedback creates a response that moves the variable in the opposite direction
is homeostatic negative feedback an open or closed loop?
closed, it keeps a variable toward the set point
set point
the averaged mean over a long period
dynamic consistency
know that the set point can be changed to the body’s needs. ex: fever
what happens when negative feedback fails?
disease/pathological condition
key component of non homeostatic feedback
amplification! if one baby in a room of 10 starts crying, they will all start crying. this is positive feedback
what kind of loop does positive feedback have?
closed loop. activates systems rapidly and requires an exit to stop. here, the integrating center is simply saying “we need more” -there is no set point in mind here. we got a problem and we gotta solve it quick!
examples of positive feedback
blood clotting, uterine contraction during childbirth
blood clotting example of positive feedback
what happens first? there’s a break in your blood vessel wall. this is where the cycle of positive feedback begins. the body needs to maintain blood pressure and blood volume. this is maintained through negative feedback (it has a set point reference). Here, the wound needs to be closed. but how? clotting. clotting needs to be a rapid process, so this action is positive feedback. after the break in the vessel happens, clotting occurs with the help of platelets. the circular cycle continues until the platelets have enough team members to get the clotting done. the recruiting process will continue until then. clotting proceeds, then the cycle may end when finished clotting.
what detects changes of a biological parameter such as skin temperature?
sensor
what directly activates effectors?
efferent pathway
what’s an example of altered set point of the homeostatic negative feedback?
fever
what describes a bodily function that is controlled by negative feedback?
in a response to polyuria, you drink more water
what describes a bodily function that is controlled by positive feedback?
bleeding from a cut activates the platelets until a plug is formed
T/F
if anatomy is about how the brain looks, physiology is about how the brain functions
true
T/F
hypothesis is a proven conclusion
false
T/F
the sensor detecting changes in a physiological parameter relays the information to the integrating center via the efferent pathway
false
T/F
positive feedback is an open loop homeostatic mechanism that amplifies the input signal
false
T/F
blood clotting is an example of a closed loop positive feedback that the body responds to bleeding
true
T/F
negative feedback is an open loop feedback mechanism that is used to maintain the internal stability
false
what’s a stem cell
an undeclared cell. it can duplicate and change into many different cells
zygote
can make everything. zygote can turn to totipotent cell
totipotent cell
can turn into an embryo/placenta
pluripotent
can develop into any cell type of the body, but not embryo
pluripotent turns to multipotent, which can then turn into a limited number of cells with the same lineage
ectoderm line
ectoderm cells: nuerons, glial cells, epidermis, retina/lens, pigment cells
mesoderm line
mesoderm cells. connective tissue, skeletal muscles, smooth muscles, urogenital system, adipose tissue, blood cells
endoderm line
endoderm cells. pulmonary alveoli, thyroid gland, pancreatic cells
4 basic types of cells
nerve cell, muscle cell, epithelial cell, connective cell
nerve cell
brain, spinal cord, nerves
muscle cell
cardiac muscle, smooth muscle, skeletal muscle
epithelial tissue
lining of GI tract organs and other hollow organs, skin surface (epidermis)
connective tissue
fat and other soft padding tissue, bone, tendon
connective tissue matrix amount
extensive. it is the glue because it secretes extensive amount of matrix
epithelial matrix type
basement membrane
muscle cell unique feature
able to generate electrical signals, force, and movement
nerve cell unique feature
able to generate electrical signals
a cell
the smallest unit. basic unit of the body. 100 trillions of cells work together
a tissue
a group of the same cells
an organ
consists of multiple tissues that work together to perform a specific function
an organ system
consists of multiple organs that work together for a specific job
ten organ systems of our body
immune, digestive, cardiovascular, integumentary, respiratory, endocrine, reproductive, excretory, musculoskeletal, nervous
hyperplasia
increased reproduction rate of cells causes larger size in organ/tissue
hypertrophy
increase and growth of muscle cells
metaplasia
cells change form
dysplasia
abnormal cell type in a tissue (hearts and stars and circles)
nucleus
the site of DNA replication and transcription
nucleoli
dense structures which contain genes for forming the RNA associated with ribosomes
chromatin
threadlike material composed of DNA plus histone proteins
the nucleus is the site of
DNA duplication (for cell division), transcription (DNA to primary RNA), and RNA processing (primary RNA to mRNA)
what does helicase do
unwinds the DNA double helix. this is part of DNA replication in the nucleus
what does DNA polymerase do
makes a new strand utilizing template. this is part of DNA replication in the nucleus
transcription
nucleus is the place. RNA polymerase is needed. substitution from T in DNA sequence to U in RNA sequence
exons
coding sequence
introns
noncoding sequence
ribosome
site of translation. consists of 2 subunits: small (function: decoding mRNA codons), and large (function: formation of peptide bonds)
summary of gene expression
transcription occurs in the nucleus (DNA -> primary RNA -> mRNA)
translation occurs in the ribosome (mRNA -> protein)
where do free ribosomes function
the cytosol
what do membrane bound ribosomes do
synthesize proteins that are bound for organelles in the rough ER, golgi apparatus, lysosome, or plasma membrane
rough endoplasmic reticulum
with ribosomes. membrane proteins and secretory proteins
smooth endoplasmic reticulum
without ribosomes. lipid/steroid synthesis and calcium storage
golgi apparatus
site of modification, packaging, and trafficking of secretory protein or membrane proteins
mitochondria
site of ATP synthesis and cellular respiration
lysosome
garbage disposal for your cell. contains digestive enzymes. digests damaged cell organelles
peroxisome
detox center for your cell. produces hydrogen peroxide
cytoskeleton
for movement of organelles as well as shape/movement of a cell
microfilament
fine, thread-like protein fibers made of actin. gliding, contraction, cytokinesis
intermediate filament
provide tensile strength for the cell: keratin
microtubule
cylindrical tubes of tubulin. determines the cell shape and movement of cell organelles and vesicles
plasma membrane
site of cell boundary and transcellular movement of solutes and solvents
ICF
intracellular fluid. 2/3 of body’s water
ISF
interstitial fluid
ECF
extracellular fluid. 1/3 of body’s fluids. composed of interstitial fluid and plasma
major components of the plasma membrane
phospholipid bilayer and proteins
what do lipids do
repel water but pass small hydrophobic molecules like gases and steoids
is the head of a phospholipid hydrophobic or hydrophilic
hydrophilic
is the tail of a phospholipid hydrophobic or hydrophilic
hydrophobic
what do unsaturated fatty acid tails do
increase the membrane fluidity. this is what causes the bent bobby pin tail
integral membrane proteins
proteins that are embedded in the lipid bilayer. transmembrane proteins for channels, carriers, receptors. shoe lace that is going through the lace holes
peripheral proteins
proteins that are not embedded in the lipid bilayer. shoelace part that is tied, not bound to the lace holes
the embryonic stem cells that can differentiate into any cell type of the body but cannot make a placenta is an example of __________ cells
pluripotent
which cell secretes an extensive extracellular matrix?
connective cells
transcription occurs in the __________ whereas translation occurs in the ________
nucleus, ribosome
damaged cell organelles are digested in the _______ whereas modification of toxins occurs in the ________
lysosome, peroxisome
actin is a _________ whereas keratin is an _________
microfilament, intermediate filament
the plasma membrane is consisted of
phospholipid, proteins, cholesterol, carbohydrate
T/F
hematopoietic stem cells are pluripotent
false
T/F
connective tissue cell type secretes a large amount of extracellular matrix
true
T/F
upon DNA replication, there are one old DNA double strands and one new DNA double strands
false
T/F
transcription is the cellular process of making single-stranded RNA using a non-coding strand of DNA as a template
true
T/F
Translation occurs only in ribosomes that are attached to the endoplasmic reticulum
false
T/F
mitochondria is abundantly present in red blood cells which must deliver oxygen to other cells
false
T/F
damaged cellular organelles are digested/broken into recyclable components in peroxisome
false
T/F
Most of the body’s water is found in the plasma
false
T/F
the plasma membrane is made of the phospholipid bilayer, proteins, cholesterol, and carbohydrates
true
T/F
the plasma membrane with a high percentage of polyunsaturated fatty acids would have a higher fluidity and thus easily pass gases
true
extracellular fluid is made up of
interstitial fluid and plasma
osmolarity
the total solute concentration
Na+ concentration is higher in the extracellular fluid or intracellular fluid?
extracellular. 142 mmol/l
K+ concentration is higher in the extracellular fluid or the intracellular fluid?
intracellular. 155 mmol/l
Cl- concentration is higher in the extracellular fluid or the intracellular fluid?
extracellular. 115 mmol/l
protein is negligible where?
interstitial fluid
where does osmolarity remain in ICF?
300 mOsM
1 liter solution of 2 moles of NaCl has a total osmolarity of ______ OsM
4
what does the plasma membrane separate?
intracellular fluid from extracellular fluid
passive transport of hydrophobic molecules by diffusion
small hydrophobic molecules. gases (oxygen, carbon dioxide). down the concentration gradient (high to low)
passive transport of hydrophilic (charged) ions
pass through integral proteins that form a channel. down the concentration gradient (high to low). Na+, K+, Ca++
facilitated diffusion
no energy required
large polar substances require carriers (revolving doors) to be attached to the bilayer as a gate
this is moved by facilitated diffusion down the concentration gradient
what is a carrier?
integral protein
characteristics of carrier-mediated transport
specificity, competition, saturation
specificity
only people in dress code can go through the revolving door
competition
everyone in a dress code competes for a spot in the revolving door
active movement
requires a carrier molecule and energy. against concentration gradient (low to high)
primary active transporters
can do it themselves. gave themselves an enzyme ATPase which gives them the energy to push against conc. gradient
primary active transporters can do what
pump Na+ and K+ in opposite directions
osmosis
water moving in and out of the cell
tonicity
cell maintains volume (doesn’t change)
in order for osmosis to occur…
there must be a difference in solute concentration and the membrane must be selectively permeable to water
movement of solvent/water
passive movement by diffusion, no energy required
in the absence of the solute concentration gradient, water will _________ across the membrane
not move
in the presence of the solute concentration gradient, water will ________ across the membrane
move from the low solute concentration to the high solute concentration
how is osmolarity and tonicity related
water movement across the cell membrane would change the volume of the cell
hypotonic
less than 300 mOsm. a lower osmolarity than the inside of a cell. water will move into the cell. cell swells
isotonic
300 mOsm. the same osmolarity as the inside of the cell. no water movement, cell remains intact.
hypertonic
greater than 300 mOsm. a higher osmolality than the inside of a cell. water moves out of a cell. cell shrinks
exoctosis
intracellular -> extracellular
endycytosis
extracellular -> intracellular
passive transport includes
simple diffusion, ion channel, facilitated diffusion
what transports require energy
active and vesicle-mediated
passive diffusion
no energy required. simple diffusion through lipid layer or ion channels. facilitated diffusion through carriers
active transport
energy required. primary and secondary active transporters through carriers
movement of solvents/water
osmosis
our cell is surrounded by interstitial fluid with the osmolarity of _______
300 mOsm
diffusion of ions through a specific ion channel depends on
concentration gradient
a red blood cell would _____ in the solution of 200 mOsm because water would move ________ the red blood cell
burst, into
T/F
Na+ ion is at equilibrium at the same concentration across the cell membrane
false
T/F
osmolarity of the plasma remains at 300 mOsm
true
T/F
osmolarities between 1m glucose and 1m NaCl solutions are the same
false
T/F
diffusion is a passive movement of a molecule that occurs down its concentration gradient at the expense of energy expenditure
false
T/F
exocytosis is an active transport that requires energy
true
resting membrane potential
the inside of the cell compared to the outside of the cell at rest (-90 to -65 mV)
depolarization
the membrane potential becomes less negative, inside the cell becomes more positive
repolarization
return to the RMP
hyperpolarization
the membrane potential becomes more negative, inside the cell becomes more negative
how does de/re/hyper polarization happen?
change in permeability. ions go through ion channels
characteristics of ion channels
selectivity (sodium channels only allows sodium), gating (closed v open, inactivated or desensitized).
passive ion channels
leaky channels, always open. K+ leaking down its concentration gradient
voltage gated channels
open/close when a membrane potential change is detected. open + inactivate when membrane depolarizes. close when membrane repolarizes
chemically-gated ion channels
open when a ligand (neurotransmitter) binds to it
when does depolarization occur
when membrane permeability to Na+ (and/or Ca++) increases.
when more permeable to sodium
which 2 cell types generate action potentials
nervous cells and muscle cells
what do dendrites receive
incoming signals (graded potentials)
what does the amplitude of graded potentials depend on?
the strength of the stimulus
excitatory
depolarize
inhibitory
repolarize/hyperpolarize
temporal summation
2 excitatory potentials will summate if they arrive in the axon hillock within a short period of time
spatial summation
3 presynaptic potentials can summate to generate excitatory postsynaptic potential
EPSP
excitatory postsynaptic potential. depolarization
IPSP
inhibitory postsynaptic potential. repolarization or hyperpolarization
if there is an inhibitory signal….
spatial summation: inhibitory and excitatory signals may “cancel” and not get an AP
divergence
the “family tree” neuron. the AP that neuron 1 generates impacts the properties of following neurons
convergence
reverse family tree. multiple neurons down to one signal
summation is about
graded potentials in a cell
pathways are about
levels of signals and their amplifications
which cell types have action potentials?
neurons and muscle cells
during the upstroke of a neuronal action potential, the membrane permeability to _____ increases
Na+
which type of ion channel is important for the initial depolarization of the neuronal AP?
voltage gated Na+ channel
which does not decrease in strength as it moves away from the stimulus?
action potentials
a graded potential that causes a depolarization is
excitatory
the potential where an action potential is generated is called
threshold
the opening of which channel type would likely cause an inhibitory postsynaptic potential?
gated K+
absolute refractory period
membrane is incapable of producing another AP. vg Na+ channels are open or inactivated
relative refractory period
axon membrane can produce another AP but requires a stronger stimulus
nodes of ranvier
the spaces between myelin. contains vg na+ and k+ channels
saltatory conduction
salta/brinca= jump. jumping from node to node, fast rate of conduction
electrical synapse
gap junctions allow direct ionic current flow between cells. smooth and cardiac muscles, glial cells
chemical synapse
uses neurotransmitters released from presynaptic neuron that bind to receptor proteins on postsynaptic cell
ionotropic receptors
chemically gated ion channels. rapid, short acting
metabotropic receptors
g-protein coupled receptors. generate graded potentials. slow acting and long term effects
acetylcholine (Ach)
both exitatory and inhibitory
nicotinic Ach receptors
ionotropic, excitatory. found in: autonomic ganglia and skeletal muscle fibers
muscarinic Ach receptors
metabotropic, found in the plasma membrane of smooth and cardiac muscle cells
epinephrine
monoamine NT, peripheral nerves and adrenal medulla
norepinephrine
monoamine NT, central nervous system and peripheral nerves
serotonin
monoamine NT, CNS
dopamine
monoamine NT, CNS
glutamate and NMDA
amino acid NT, CNS, excitatory
glycine and GABA
amino acid NT, CNS, inhibitory
polypeptides
CCK (satiety), neuropeptide Y (appetite), substance P (pain), endorphins (analgesic). metabotropic receptors
gap junctions form
electrical synapse
organization of the nervous system
afferent pathway -> central nervous system -> efferent pathway
peripheral nervous system glial cells
schwann cells, satellite cells
central nervous system glial cells
astrocytes, microglia, oligodendrocytes, ependymal cells
schwann cells
wrap around axons to form myelination. (each myelination cloud is a schwann cell)
satellite cells
basic function: support
support neuron cell bodies with ganglia
oligodendrocytes
similar to schwann, form a myelin sheath around axons of CNS, except one oli can contribute to several myelination segments on dif axons
microglia
phagocytes that help get rid of foreign substances in the CNS
astrocytes
basic function: support
helps maintain a normal environment around neurons. maintains blood brain barrier. keeps blood out of cerebral spinal fluid
ependymal cells
line the cavities of the brain and spinal cord, make cerebrospinal fluid
chemoreceptors
chemical stimuli in env
photoreceptors
eye. rods and cones
thermoreceptors
temperature
mechanoreceptors
touch and pressure
nociceptors
pain
proprioceptors
body position
grey matter is comprised of
cell bodies, dendrites, synapses
white matter is comprised of
axons connecting different parts of grey matter
forebrain
thalamus, cortex, limbic system
thalamus
relay station channeling sensory information
cortex
control sensory processing, motor control, thought, memory
limbic system
basic emotions, drives, behaviors
hypothalamus
master controller of the endocrine system
amygdala
sensations of pleasure/fear
midbrain
reticular formation. filters sensory input, filters thoughts to avoid sensory overload.
hindbrain
cerebellum, medulla oblongata
cerebellum
coordinates movements, stores some motor memory
medulla oblongata
controls autonomic functions (respirations, cardiac, vomiting, swallowing)
sensory motor neurons
go into the central nervous system. part of the peripheral system
efferent motor pathways
exit the central nervous system. part of the peripheral system. 2 pathways: somatic (voluntary) and autonomic (involuntary)
somatic nervous system
carries signals from the CNS to the skeletal muscles (which serve as the effector) to control movement
autonomic nervous system
regulates smooth muscle, cardiac muscle, and glands
sympathetic nervous system
fight or flight
parasympathetic nervous system
rest & digest
sympathetic nervous system effects what
dilates pupils, speeds heart rate, speeds breathing, inhibits digestion, produces sweaty palms
parasympathetic nervous system effects what
contracts pupils, slows heart rate, slows breathing, stimulates digestion, dries palms
vagus nerve
effector organs: heart, lungs, most visceral organs
sympathetic pathway:
CNS -> Ach leaves as neurotransmitter -> binds to nicotinic receptor -> autonomic ganglion -> norepinephrine as neurotransmitter -> binds to adrenergic receptor on the target tissue
parasympathetic pathway:
CNS -> Ach leaves as neurotransmitter -> binds to nicotinic receptor -> autonomic ganglion -> Ach leaves as neurotransmitter -> binds to muscarinic receptor on the target tissue
adrenal sympathetic pathway:
CNS -> Ach releases into adrenal medulla -> epinephrine gets released as neurotransmitter into blood stream -> goes everywhere
what does the sympathetic preganglionic neuron release
Ach
what does the parasympathetic preganglionic neuron release
Ach
what does Ach from the sympathetic pathway bind to
nicotinic receptor (ionotropic)
what does Ach from the parasympathetic pathway bind to
nicotinic receptor (ionotropic)
sympathetic postganglionic neuron releases
norepinephrine
parasympathetic postganglionic neuron releases
Ach
sympathetic norepinephrine binds to
adrenergic receptors (metabotropic)
parasympathetic Ach binds to
muscarinic receptors (metabotropic)
epinephrine is secreted from __________
the adrenal medulla
which type of Ach receptor is on the postganglionic neurons of parasympathetic and sympathetic nerves?
nicotinic
a receptor that is on skeletal muscle cells
nicotinic
