uworld bio rev Flashcards
what comprises the inner wall of all blood vessels
a single layer of endothelial cells
single layer of endothelial cells forms a
barrier that regulate entry/exist of materials into/out of bloodstream
what do endothelial cells secrete?
chemical signals that prevent clotting
injury to a blood vessels triggers
1) formation of platelet plug
2) clot is strengthened
formation of platelet plug means…
endothelial damage exposes connective tissue outside blood vessels
platelets bind connective tissue (i.e. collagen fibers) to form PLATELET PLUG out of vessel
where are platelets derived from
bone marrow
bound platelets and endothelial cells near site of damage continue…
to release signals that enhance platelet aggregation
where are clotting factors synthesized
mainly in the liver
clotting factors are specialized…
proteins that activate in response to platelet aggregation + signaling factors outside vessel
activated clotting factors induce processes that lead to…
formation of the enzyme thrombin
thrombin induces
protein strands (i.e. fibrin) to form an adhesive mesh-like structure over the platelet plug (reinforcing clot)
synapses are
gaps b/w presynaptic and postsynaptic neuron
can be electrical or chemical in nature
synapses are important in allowing
communication bw an axon terminal of a presynaptic neuron
AND dendrites of a postsynaptic neuron from an action potential
neurons communicate with
one another via action potentials
an action potential travels down the…
signaling cell (presynaptic neuron) until it reaches the axon terminals
axon terminals are responsible for
signal transmission across synapse to the postsynaptic neuron
synaptic transmission via ligand-gated ion channels
1) action potentials reach axon terminal
2) Ca2+ channels open
3) Ca2+ ions enter cell
4) Ca2+ triggers neurotransmitter release via exocytosis
5) neurotransmitter binds ligand-gated ion channels to allow ions thru
6) inhibitory or excitatory cell response
glutamate (glu)
primary excitatory neurotransmitter of CNS
involved in learning and memory
GABA
primary inhibitory neurotransmitter of brain
glycine (gly)
primary inhibitory neurotransmitter of the spinal cord
dopamine (DA)
can be excitatory or inhibitory
involved in cognition, attention, movement, reward
serotonin (5-HT)
mainly inhibitory
involved in sleep, appetite, mood
norepinephrine (NE)
can be excitatory or inhibitory
involved in sympathetic signaling in the ANS
acetylcholine (ACh)
involved in parasympathetic signaling in the ANS
released by motor neurons at neuromuscular junctions of the somatic NS –> excites skeletal muscle
synaptic transmission of excitatory neurotransmitters
1) AP reaches axon terminal
2) AP causes Ca2+ channels to open –> Ca2+ in presynaptic neuron’s axon terminal
3) Ca2+ triggers neurotransmitter release via exocytosis
4) excitatory NT binds ligand-gated ion channels to allow Na+ ions into postsynaptic neuron
5) Na+ ions depolarize membrane potential + promote AP initiation
synaptic transmission of inhibitory NTs
1) AP reaches axon terminal
2) AP causes Ca2+ channels to open
3) release Ca2+ into presynaptic neuron’s axon terminal
4) inhibitory NT binds ligand-gated ion channel to allow Cl- ions into post synaptic neuron
5) Cl- ions cause membrane potential to hyperpolarize + inhibit AP initiation
what happens to chemical synapses?
AP in presynaptic neuron releases NTs
NTs bind receptors on membrane of postsynaptic neuron
classification for NTs
excitatory - AP MORE likely to occur in the postsynaptic neuron
inhibitory - AP LESS likely to occur in postsynaptic neuron
APs are electrical signals that travel from
a neuron’s cell body down its axon and to its axon terminals
during APs, membrane potential of the neuron…
changes due to opening/closing of voltage-gated Na+ and K+ ion channels
at rest, a neuron maintins a potential difference known as…
resting membrane potential (RMP) of ~ -70 mV
meaning that intracellular space is 70 mV more neg than extracellular space
RMP is maintained by the
Na+/K+ pump and K+ leak channels
Na+/K+ pump and K+ leak channels are always..
open and allow passive diffusion of K+ across membrane
stimulus may cause voltage-gated Na+ channels to open and then….
Na+ rushes into cell –> depolarize membrane
membrane potential is (+)
if depolarization is enough to reach a certain…
threshold, an AP is initiated in the neuron
if the threshold is reached…
voltage-gated Na+ channels remain open
futher rapid depolarization of membrane occurs
Na+ entry causes AP to reach its
peak (overshoot) –> membrane potential is at most positive
voltage gated Na+ channels close and voltage gated K+ channels open to go back to RMP
K+ rushes out of neuron after K+ channels open and result in
REPOLARIZATION
voltage gated K+ channels close more slowly so…
membrane potential becomes more neg briefly than the RMP (i.e. HYPERPOLARIZATION)
when voltage gated K+ channels close…
RMP is restored
during an AP, the opening/closing of voltage gated channels determines
state of membrane polarization and propogation of AP
if voltage gated K+ channels are downregulated…
repolarization would occur more slowly
results in neuron hyperexcitability
neurons are responsible for
sending electrical signals to other cells
neuroglia provide support functions to
neurons and the nervous system
types of neuroglia in CNS
ependymal cells
oligendrocytes
microglia
astrocytes
what type of cell lines compartments and produced cerebrospinal fluid
ependymal cells
what do oligondendrocytes do
form myelin sheath around axons to reduce ion leakage
decrease capacitance
increase AP propagation speed along axon
microglia serve as
immune cells which phagocytize pathogens/damaged cells/waste materials
astrocytes
contact blood vessels
regulate blood flow to coordinate synaptic activity/chem changes
important in maintaining extracellular fluid/ion/pH/NT homeostasis
provide nutrient for neuron function
types of neuroglia in PNS
schwann cells
satellite cells
schwann cells form
myelin sheaths around axons to increase conduction speed
satellite cells provide
structural support and support nutrients to neurons
oligendrocytes myelinate
CNS axons
pathway of fluid/liquid transport in lympathic system
interstitial fluid
lymph capillaries
lymph vessels
lymph duct
vein
reflexes are involuntary responses to
stimuli
may or may not require input from brain
a reflex arc is the specific neuronal pathways that
helps the direct muscular or glandular effect associated w a specific reflex
reflex arcs begin with the
stimulation of a sensory neuron
electrical impulse then travels down spine/brain along sensory nerve
electric impulse from reflex arc can be transmitted either:
directly
indirectly
direct impulse transmission
directly transmitted to effector neuron (monosynaptic reflex arc)
indirect impulse transmission
indirect transmission through interneuron
interfaces w/ effector neuron (i.e. polysynpatic reflex arc)
electrical impulses initiated in effector neurons leave the CNS and…
travel along effector neuron to stimulate muscle fiber/gland/ganglionic neuron
this is done either directly or after synapsing w/ a postganglionic effector neuron
when the effector neuron synapses with a muscle fiber, it is referred to as
a motor neuron
autonomic reflex arcs are always
polysynaptic
e.g. gustatory-salivary reflex
reflexes can be modulated by…
input from the brain
in the case of polysynaptic reflexes, this modulation takes the form of…
descending signals from higher areas in the CNS that act on preganglionic neurons in the reflex arc
soma of both interneuron + preganglionic neuron within CNS could be….
acted upon by descending input from higher brain centers to alter gustatory-salivary reflex
what are reflexes mediated by?
reflex arcs
neuronal pathways (incl a sensory neuron)
an effector neuron
possibly an interneuron
membrane-bound receptors respond to ligands that are either:
endogenous (originating from organism)
exogenous (foreign to organism)
agonists are ligands that
activate the receptor and promote its downstream effects
antagonists are ligands that
deactivate or inhibit the receptor
prevent its downstream effects
cholinergic signaling involves
acetylcholine (ACh)
cholinergic neurons secrete
ACh which binds to cholinergic receptors
parasympathetic pathways utilize ACh for signaling between
pre and postganglionic neurons
as well signalling bw the postganglionic neuron and target tissue (e.g. salivary glands)
the gustatory-salivary reflex arc is mediated primarily by
parasympathetic pathways
exerts effects (i.e. stimulation of salivation) through cholinergic signaling
name what the parasympathetic division of the NS promotes
E conservation and storage
lower heart rate
decreased air flow
stimulating digestion (e.g. salivation, release of digestive enzymes, peristalsis)
inc glucose uptake
glycogenesis
name what the sympathetic division of the NS promotes
oxygen delivery to skeletal muscles is maxed
increased heart rate
dilated airways
constricted blood vessels
glycogen in liver –> glucose to provide energy for skeletal muscles
pupils dilate to max light intake
step 1 of neural process of receiving/acting on sensory info in a reflex arc
sensory receptors detects stimulus
sensory receptors are highly specialized nerve endings that
respond/recognize to highly specific types of stimuli (e.g. chemical, light, pressure, vibration)
2nd step of neural process
activated sensory neuron sends an afferent sensory signals (electrical impulse) –> CNS
elec impulse is transmitted to an interneuron or effector neuron
remember: Afferent Approaches CNS
3rd step in neural process
interneurons in cns in brain/spinal cord act as integration center
sensory/CNS input are processed and consolidated
interneurons can relay sensory info to brain + integrate signals from brain into reflex response
interneurons transmit signal directly to effector neuron
interneurons are not present in every reflex arc
input from brain is not always needed for reflex completion
4th step in neural process
effector neuron generates/sends an efferent signal that travels TOWARD the target organ (muscle or gland)
REMEMBER: Efferent info Exits CNS
5th step in neural process
effector (target) organ generates desired response to stimulus
within the gustatory-salivary reflex, the sensory neuron makes up the
afferent component of the reflex arc
sensory neuron transmits impulses toward the CNS
pre and postganglionic fibers make up the
efferent component of the reflex arc
fibers transmit impulses away from the spinal cord
preganglionic neuron corresponds to
the efferent component of the gustatory-salivary reflex
pregang neuron sends impulses AWAY from CNS
sensory neuron corresponds to the
afferent component of the gustatory salivary reflex
sensory neuron sends impulses TOWARD the CNS
interneuron propogates signals within the
CNS
impulses are not generated
impulses do not travel directly or away from the CNS
interneurons is neither afferent/efferent
input from higher areas in the CNS can modulate
activity of reflexes by either strengthening or weakening magnitude of the response
the nodes of Ranvier increase the rate of
depolarization toward the axon terminal
nodes of Ranvier are sites of
ion flux across myelinated axons
nodes of ranvier are sites of interrupted myelination that
contain voltage-gated channels
when and where are an AP generated?
generated in a neuron when
the soma depolarizes enough that membrane potential reaches a threshold for voltage-gated channels opening
after AP is generated, voltage-gated channels open in a…
coordinated fashion, allowing a series of ionic movements across plasma membrane to occur
ionic movements across plasma membrane allow…
rapid maximal depolarization of a small area of the membrane due to Na+ transport into cell
after maximal depolarization of membrane occurs…
rapid repolarization as Na+ channels close and K+ channels open
allowing K+ to leave the cell
APs ‘move’ along an axon toward the
axon terminal as successive regions are depolarized
manner in which APs move is
influenced by myelin
what forms myelin
formed by plasma membrane from glial cells
portions of glial cell plasma membrane are wrapped….
many times around an axon
insulating axon and preventing ion flow across axon membrane
wave of ion transport is continuous along…
myelinated axons
but ‘jumps’ in a discontinuous fashion along myelinated axon bc of the insulation provided by myelin
what influences rate at which a neural impulse is conveyed?
axon size
myelination
larger diameter axon that are myelinated transmit
neural impulses FASTER than smaller/unmyelinated axons
myelination can prevent
the loss of current along an axon
by exposing a short segment of an unmyelinated axon, the node of Ranvier promote…
entry of extracellular Na+ into axons
while limiting number of open ion channels
GREATLY increases rate at which neural impulses conduct along myelinated axons
drug that blocks release of adrenocorticotropic hormone from anterior pituitary would
decrease secretion of cortisol from adrenal cortex
viroids are
subviral infectious particles that consist of short circular single strand of RNA
viriods have regions where
RNA binds with itself
creating some double-stranded areas of circular genome
RNA-composing viroids does not
generally code for protein unlike VIRUSES that have protein coats (capsids)
when infecting cells, viroids can bind….
host cellular RNA sequences
results in gene silencing preventing synthesis of necessary proteins
ribosomes are composed of
specific proteins and rRNA
ribosomes translate…
mRNA sequences into proteins in all cells
substituting first (5’) nucleotides often
alters the AA
substituting the second nucleotide always
alters the AA
substituting the 3rd (3’) nucleotides doesn’t
often alter the AA
64 codons =
genetic code
64 codones code for how many AAs
20 AAs
what does it mean that the genetic code is degenerate?
multiple codons can code for the same AA
protein-coding genes consist of
multiple codons
sequences of three nucleotides that code for a specific AA
during translation, each mRNA codon base-pairs with…
a corresponding tRNA that is charged w/ a specific AA
DNA mutations in the protein-coding regions of a gene may alter…
the sequences of transcribed mRNAs
creating changes in AA structure of encoded proteins
what do silent mutations alter
DNA/RNA sequences
silent mutations DON’T alter
protein structure
mutations in the third position often
code for the same AA
making them silent mutations
why do mutations in the third position often code for the same AA?
wobble (less stringent base pairing) at third position of mRNA codone and tRNA anticodon
resting state in sliding filament model fo muscle contraction
Ca2+ absence makes tropomyosin block myosin-binding sites of actin filament
cross-bridge formation involves myosin heads binding to
myosin-binding site
ATP hydrolysis is where
myosin head shifts back to high-energy position
power stroke is where myosin head
pulls actin filament to center of sarcomere
cross-bridge dissociation involves the myosin head…
being released into low-energy position
what is muscle contraction dependent on?
interaction bw myosin (thick) and actin (thin) protein filaments in sarcomere
sarcomere is the
basic contractile unit of muscle tissue
immune system comprises both of what types of immunity
adaptive and innate
cells of the innate immune system can
RAPIDLY and NONSPECIFICALLY recognize and destroy foreign antigens
adaptive immune system is subdivided into
cell mediated immunity
humoral immunity
adaptive immune system comprises of cell that can
recognize SPECIFIC antigens
mount more specialized immune responses against pathogens
in cell mediated immunity, what do t-cells do
recognize + mount immune responses against foreign antigens displayed by MHC proteins
MHC proteins on any given cell display…
fragments of any proteins present within that cell
cells containing foreign pathogens will generally…
display protein fragments (antigens) on their MHC proteins
helper t-cells are t-cells that
recognize foreign antigens displayed by MHC proteins of other immune cells
B-lymphocytes are cells that
bind and engulf a foreign antigen
the antigen engulfed by the B-lymphocyte is
broken down into fragments and transported to be displayed on MHC proteins on cell membrane
helper T cell bind the foreign antigen presented by the
b-lymphocyte and releases cytokines
cytokines induce division of b-lymphocute into identical cells
division of b-lymphocyte by cytokines leads to…
differentiation of identical cells to b-lymphocyte to secrete antibodies against invading pathogen
macrophages and dendritic cells engulf
foreign antigens via phagocytosis
macrophages and dendritic cells present antigen fragments on
MHC proteins found on cell membrane
a low count of helper T cells would affect the
activation of cytotoxic t cells and b-lymphocytes (produce antibodies against bacterium)
MHC protein’s expression is solely dependent on
transcriptional and translational machinery
because of MHC”s dependence on a cell’s transcriptional/translational machinery…
cells would still be able to display bacterial antigens on their MHC proteins regardless of helper T cell count
helper T cells bind
foreign antigens presented on other immune cells
helper t cells release
signalling molecules that enhance immune responses
such as cytotoxic T cel activation and antibody production by B lymphocytes
in the absence of external energy input, molecules in solution will
diffuse from areas of high to low concentration
this is THERMODYNAMICALLY FAVORABLE
molecules that separated from an area of lower concentration by a membrane will…
STILL FLOW across a membrane down their concentration gradient
as long as the membrane is permeable to those molecules
osmoregulation is the
homeostatic process by which organisms actively assess their environment + regulate internal concentration of fluid/electrolytes
in the absence of osmoregulation, what happens
saltwater fish would tend to absorb salt and lose water
because saltwater fish tend to absorb salt and lose water, their osmoregulatory systems do what
combat this process by using energy to excrete salt and absorb water
freshwater teleosts live in an environment where water concentration is (x) and salt concentration is (y)
higher water concentration and lower salt concentration outside their bodies than inside
in the absence of osmoregulation, salt ions will tend to move to
the lower concentration environment of the exterior freshwater
water molecules do the opposite
what is involved in osmoregulation in marine teleosts?
1) seawater ingestion
2) retrieval (absorption) of salt and water from the intestine
3) excretion of DIVALENT ions through urine
4) excretion of MONOVALENT ions through urine
examples of divalent ions
Mg2+ and SO4^2-
monovalent ions examples
Na+ and Cl-
start codon is
AUG
stop codons
UAA
UAG
UGA
STEP 1 OF TRANSLATION: nuclear genes are initially transcribed by
RNA polymerase to pre-mRNA
STEP 2 OF TRANSLATION: pre-mRNA is then converted into
mature mRNA in a process including splicing to remove introns
STEP 3 OF TRANSLATION: mature mRNA is then
transported out of the nucleus into the cytoplasm
mature mRNA –> protein by ribosomes
each AA in a protein is encoded by
a corresponding mRNA codon that binds anticodon of tRNA that is charged with a specific AA
direction of mRNA translation
5’ to 3’ direction
mRNA translation starts at
start codon (AUG)
continues until stop codon (UAA, UAG, UGA) is reached
stop codon does not code for an AA but instead
binds a release factor that promotes dissociation of the translation complex
regions upstream of the start codon and downstream of the stop codon are referred to as
untranslated regions (UTRs)
UTRs do not
code for AAs
a mature mRNA consisting of 500 molecules was translated into a 110 AA protein, what is the number of nucleotides?
110 amino acids x 3 nucleotides per codon = 330 nucleotides
the 330 nucleotides of this mRNA molecules are translated into
amino acids of the protein
number of nucleotides that do not code for AAs can be calculated via
500 total nucleotides - 330 coding nucleotides = 170 noncoding nucleotides
what acts like the framework in eukaryotic cells?
internal cytoskeleton
provides shape and internal structure to cells + organization
cytoskeleton is made of a network of fibers…
interspersed throughout the cytoplasm and consists of three major components
three major components of cytoskeleton
intermediate filaments
microfilaments
microtubules
intermediate filaments are composed of
several protein types
e.g. keratin and lamin
intermediate filaments perform the following functions:
1) work with microfilaments to determine shape
2) make up the nuclear lamina (inner lining of nuclear envelope)
3) assist in anchoring organelles to specific compartment within the cell
4) provide crucial support for cell to be able to withstand mechanical forces (e.g. compression)
when model organisms are deficient in keratins, what would happen?
organisms’s hepatocytes more fragile and unable to withstand/resist mechanical forces
may display abnormal hepatocyte phenotypes
microfilaments are made of
actin protein subunits organized into double-stranded rods
what do microfilaments help determine?
overall shape of a cell and assist in some cellular locomotion
microfilaments are responsible for
muscular contractions and forming the cleavage furrow during cytokinesis
the reduced ability of a cell to undergo cytokinesis would be a result of
the cell’s being deficient in microfilaments
microtubulues are made of
alternating alpha and beta tubulin subunits organized into hollow tubes
microtubules force the
mitotic spindle during the cell division process
microtubules are involved in
movement within the cell
facilitate vesicular transport
reduced intracellular transport of substances would be a result of
a deficiency in microtubules
what forms the cores of cilia and flagella?
microtubules
a cell having a reduced number of cilia on its surface would be a result of
a microtubule deficiency
where does fertilization occur
fallopian tube
multipotent stemms can develop into
multiple specialized cell types
what gene is responsible for the initiation of male sex determination and coding for testicles?
SRY gene
Sorry You’re A Male
afferent neurons ascend the
spinal cord and carry info to the brain
afferent = approach CNS
what hormone induces ovulation and testosterone production?
LH (luteinizing hormone)
a blastula is a
hollow sphere of cells that implants in the endometrial lining
once blastula implants itself in uterine wall, i.t. becomes…
a BLASTOCYST
bile is an important part of the absorption of what?
fat-soluble substances (vitamins A, D, E, K)
what neurons exit the spinal cord?
efferent neurons
they bring signals from the brain to the muscles/glands
golgi apparatus does what?
modifies and distributes proteins
eukaryotes only
mesoderm comprises of
muscoskeleton, circulatory system, gonads, adrenal cortex
MOVING THINGS
interneurons are part of
a reflex arc
centrioles contain
9 groups of microtubules
centrioles do what?
pull chromosomes apart
gram negative is
pink/red
has a thin wall
wall made of peptidoglycan
temporal summation is when
one presynaptic neuron releases multiple neurotransmitters over a period of time
triggers an action potential
gram positive is
purple
has a thick wall
wall is made of peptidoglycan/lipteichoic acid
lysosomes are the
demolition and recycling center
made by golgi
spatial summation si when
multiple presynaptic neurons releasing neurotransmitters at the same time
triggering an action potential
what is released in response to stress and low blood glucose concentration?
CORTISOL
released by the adrenal cortex
ectoderm develops into the
nervous system
skin, hair, mouth
action potential is the mechanism by which
electrical signals travel through the nervous system
CNS and PNS derive from
ectoderm
amplitude of an AP is
independent of the amount of current that produced it
what makes alkaline fluid to help sperm survive acidic environment of reproductive tract?
seminal vesicles and prostate glands
Na+ concentration is higher or lower outside the cell
HIGHER
microfilaments make up the cell’s
cytoskeleton
polymers of actin
K+ concentration is higher or lower inside cell
HIGHER
a polarized membrane has an electrical
potential difference across the cell membrane
electrical potential difference =
voltage
endoderm develops into
GI tract, respiratory tract, endocrine glands, bronchi, bladder, stomach
morula results from
division of a fertilized ovum
solid ball of cells
what does the hepatic portal system do
delivers deoxygenated blood to the liver to be detoxed further
before returning to the heart
when membrane is depolarized, the membrane potential becomes
MORE POSITIVE compared to resting potential
membrane potential is an
electrical potential difference b/w inside and outside of a cell
lysozyme is an
antimicrobial enzyme forming part of the innate immune system
where are lysozymes found
tears and saliva
resting membrane potential (voltage) of a cell is
~70 mV
when membrane potential is depolarized during an AP,
peak is around +40 mV
memory B cells
- formed following primary infection
- generate more robust immune response in case of re-infection
MHC-II displays
exogenous antigen to helper CD4+ T cells
when membrane is depolarized, membrane potential becomes
more positive compared to resting potential
rough ER makes proteins from
mRNA
what flows in during depolarization
Na+
what does Na+ ions flowing in do
increases charge inside cell
result in depolarization of cell membrane
fat-soluble vitamins are absorbed through the
lacteals in villi
where do Na+ ions enter cell thru
voltage-gated Na+ channels
Na+ concentration gradient drives the
movement of Na+ ions
during what phase are mRNA and proteins synthesized
G1
prepares for subsequent steps leading to mitosis
interphase includes
G1, S, G2 phases
phase where cell spends most of its life
what happens at the G2 checkpoint
cell will check that DNA has replicated correctly
what phase do cells grow and make organelles
G2
where does ETC take place in eukaryotes
inner mitochondrial matrix
explain nondisjunction
when sister chromatids don’t separate properly during anaphase
results in ANEUPLOIDY
transposons are
DNA sequences that can change their position within a genome
creates/reverses mutations
what generates antibodies to specific antigens?
B cells
require stimulation from helper T cells
part of adaptive immune system
repolarization occurs when
K+ ions EXIT the neuron
what occurs during prophase
DNA condenses
centrioles migrate to opp poles
microtubules form
hyperpolarization is when
membrane potential dips below the resting potential
when hyperpolarized, the neuron is in a
refractory period during which another stimulus is given to the neuron
2nd AP will not occur
why does hyperpolarization occur
K+ channels are slow to close
large intestine absorbs
water and salts
forms feces
t-cells are a type of
white blood cell that circulates around our bodies
scans for cellular abnormalities/infection
examples of t-cells
helper t cells
cytotoxic t-cells
suppressor t-cells
memory t-cells
hormone released by thyroid gland and builds bone
calcitonin
calcitonin increases/decreases
increase in bone/kidneys
decreases in blood/gut absorption
virions are
extracellular individual virus particles
virion contains
DNA or RNA
SS or double stranded
protein coat (capsid)
function of G0 phase
cell enters G0 phase if division isn’t necessary
what enzymes breaks AAs apart
aminopeptidase
what catalyzes the hydrolysis of peptide bonds?
trypsin
breaks proteins into smaller peptides
what happens during telophase
chromosomes decondense
nuclear membrane
cytokinesis occurs
secretin does what
release of pancreatic juices
slows motility
transduction is the
transfer of genetic material using a bacteriophage
what enzymes start the chemical digestion
amylase
lipase
helper t-cells
activate cytotoxic t-cells and macrophages to attack infected cells
or stimulate b-cells to secrete antibodies
what connects the mouth to the esophagus
pharynx
epiglottis function
prevents food from entering larynx
functional unit of exocrine pancrease
pancreatic acinar cell
acinar cell does what
synthesizes, stores, secretes digestive enzymes
pancreatic juices contain
bicarbonate
pancreatic amylase
peptidase
lipase
juices flow into the duodenum
what makes trypsin
enteropeptidase
main inhibitory neurotransmitter in spinal cord
glycine
principal site of conversion of tyrosine into catecholamines
adrenal medulla
where is the adrenal medulla located
center of adrenal gland
surrounded by the adrenal cortex which sits on top of the kidneys
CCK stimulates
bile release from gallbladder
release of pancreatic juices
promotes satiety
what responds to antigen on MCH-I and kill virally infected cells
killer cells / cytotoxic t-cells
mastication does what
breaks food down into small pieces
forms a bolus and is swallowed
what causes agglutination?
opsonizing pathogens
hormones in the duodenum that stimulate release of pancreatic juices + bile
secretin and CCK
systole
some chambers of heart muscle contract after refilling w/ blood
AV valves close
semilunar valves open
natural killer cells are a type of lymphocyte that can
recognize and kill cancer cells or cells that have been infected
natural killer cells do not
attack invading organisms directly
natural killer cells destroy
body’s own cells that have become infected or cancerous
top 3rd of esophagus is under
somatic control
middle third of esophagus is under
autonomic control
bottom third of esophagus is under
autonomic control
middle third of esophagus has combo of both
skeletal and smooth muscle
full length protein –>
free digested protein fragments –> MHC II –> T cell receptor
all nucleated cells contain
major histocompatibility complex (MHC) I molecules
pro antigen-presenting cells also contain
MHC II molecules
MHC molecules form complexes with
antigens displayed on cell surface
antigens displayed in complex with MHC molecules on cell surface bind to
T-cell receptors
neurotransmitters bind to receptors on
postsynaptic cell and make it more or less likely to fire an AP
larger current do not create
larger APs
action potentials are said to be
all or none signals
occur fully or NOT AT ALL
types of granulocytes
neutrophils
eisonophils
basophils
part of innate immune system
types of agranulocytes
monocyte
lymphocute
part of innate immune system
CO2 and H+ will trigger heme group to
release its O2
Co2 and H+ allosterically
inhibit hemoglobin
allosteric inhibition of hemoglobin means oxygen is
released near lots of Co2 or in acidic sites
which is where respiration is happening and O2 is needed
agranulocytes have no
granules
transduction is the
transfer of genetic material using a bacteriophage
