1/204
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Which group of messengers is defined as acting on cells within the same tissue?
autocrines
hormones
paracrines
eicosanoids
paracrines
A major difference between neurotransmitters and hormones is that hormones reach their destination via
direct contact on their target cell
cerebrospinal fluid
ducts
the blood
the blood
A major determinant of a hormone’s mechanism of action is
whether the hormonal molecule is hydrophobic or hydrophilic
its size
whether it is rapid acting or slow acting
if it activates gene activity or not
whether the hormonal molecules is hydrophobic or hydrophilic
Receptors for steroid hormones are commonly located
inside the target cell
on the plasma membrane of the target cell
in the blood plasma
in the extracellular fluid
inside the target cell
In order for a hormone to activate a target cell, the target cell must possess
a receptor
a second messenger
the hormone
a chaperone
a receptor
Which of these characteristics is exclusive to the endocrine system when compared with the nervous system
relies on release of chemicals that bind to specific receptors
relies primarily on negative feedback mechanisms
uses epinephrine and norepinephrine as chemical messengers
effective in coordinating cell, tissue, and organ activities on a sustained, long-term basis
effective in coordinating cell, tissue, and organ activities on a sustained long-term basis
Choose the term that does not belong in the following groupings
steroid hormone
protein hormone
second messenger
membrane receptors
steroid hormone
Choose the term that does not belong in the following groupings
glucocorticoids
steroids
aldosterone
growth hormone
growth hormone
Interaction with a membrane-bound receptor will transduce the hormonal message via
depolarization
direct gene activation
a second messenger
endocytosis
a second messenger
Second messenger-activating hormones circulate in minute quantities because
they are not important signal molecules
small concentrations of hormone can activate many intracellular signals via amplification
they are continuously released from the gland
neurotransmitters also bind to hormone receptors
small concentrations of hormone can activate many intracellular signals via amplification
Which of the following molecules act as second messengers
cAMP
Ca2+
Inositol triphosphate
all of the above
All of the above
When the pancreas releases insulin in direct response to blood glucose, this is an example of ____ stimulation
humoral
neural
hormonal
negative feedback
humoral
When an infant suckles at his mother’s breast, the mother’s neurohypophysis releases oxytocin. This is an example of _____ stimulation
humoral
neural
hormonal
negative feedback
neural
When the ovaries secrete estrogen in response to the hormone GnRH, this is an example of ____ stimulation
humoral
neural
hormonal
negative feedback
hormonal
Choose the term that does not belong in the following groupings
posterior lobe
hormone storage
nervous tissue
anterior lobe
anterior lobe
Blood levels of hormones are kept within very narrow ranges by ____ mechanisms
humoral
neural
hormonal
negative feedback
negative feedback
Which hormone is produced in the hypothalamus
ADH
ACTH
LH
GH
ADH
Hormones secreted into the hypophyseal portal system are detected by the
posterior pituitary
anterior pituitary
median eminence
infundibulum
anterior pituitary
The long bone growth-promoting effects of growth hormone are mediated by
somatosatin
somatotrophs
insulin-like growth factors
insulin
insulin-like growth factors
Secretions from corticotrophs activate cells of the ______, while secretions from gonadotrophs affect cells of the ______.
adrenal cortex; gonads
thyroid; mammary glands
gonads; adrenal cortex
mammary glands; gonads
adrenal cortex; gonads
A patient is displaying high volumes of urine output and severe dehydration. The most likely cause is
hyposecretion of oxytocin
hypersecretion of oxytocin
hyposecretion of ADH
hypersecretion of ADH
hyposecretion of ADH
Where is iodide located in the thyroid gland?
secretory vesicles inside follicular cells
lumen of follicle
golgi apparatus of parafollicular cells
cytoplasm of follicular cells
cytoplasm of follicular cells
Which of the following is an indirect effect of PTH
increasing osteoclast activity
increasing calcium absorption in the intestines
increasing calcium reabsorption in the kidney
activating vitamin D
increasing calcium absorption in the intestines
A patient is losing weight rapidly, sweating profusely, and is always anxious. The patient may be suffering from
hypothyroidism
cretinism
hyperthyroidism
hypersecretion of calcitonin
hyperthyroidism
______ is the adrenal hormone responsible for maintaining appropriate blood sodium levels
cortisol
DHEA
aldosterone
epinephrine
aldosterone
Why are diabetics continuously thirsty and why do they frequently urinate
less water is reclaimed by osmosis in the kidneys
water loss reduces blood volume, promoting secretion of ADH
Glucose is lost in the urine, which increases blood volume
1 and 2 are correct
1 and 2 are correct
In what ways are hormonal effects of epinephrine and norepinephrine from the adrenal medulla similar to the effects of glucocorticoids from the zona fasciculata
hormones from both are under the ultimate control of the sympathetic nervous system
both increase cardiac activity and blood pressure
both are stimulated by angiotensin II
both increase blood glucose levels and promote the breakdown of stored fats into fatty acids
both increase blood glucose levels and promote the breakdown of stored fats into fatty acids
Which of the following is not an action of glucagon
release of glucose into the blood by liver cells
transport of glucose into most body cells
synthesis of glucose from lactic acid
breakdown of glycogen
transport of glucose into most body cells
The secretion of ____ helps regulate our circadian rhythms
estrogen
testosterone
thyroid hormones
melatonin
melatonin
Which of the following structures produces a hormone responsible for stimulating red blood cell production
stomach
heart
kidney
skin
kidney
Which of the following structures produces a precursor to hormonal vitamin D, immportant for CA2+ regulation?
stomach
heart
kidney
skin
skin
After centrifuging, which of the listed blood components contains the components of immune function
Plasma
buffy coat
erythrocytes
hematocrit
buffy coat
The major function of the most common plasma protein, albumin, is
maintenance of plasma osmotic pressure
buffering changes in plasma pH
fighting foreign invaders
both 1 and 2
both 1 and 2
Red blood cells are efficient oxygen transport cells. of the following characteristics, which is the major contributor to the significant oxygen-carrying capacity of a red blood cell
red blood cells lack mitochondria
red blood cells don’t divide
red blood cells are biconcave discs
red blood cells contain myoglobin
red blood cells lack mitochondria
Each hemoglobin can transport ___ oxygen molecules
4
40
400
4000
4
Oxygen binds to the ___ portion of hemoglobin
globin
oxyhemoglobin
iron atom
amino acid
iron atom
A patient with low iron levels would experience which of the following symptoms
an increased white blood cell count
an increase in energy level
an increase in fatigue
a decreased white blood cell count
an increase in fatigue
A hematopoietic stem cell will give rise to
erythrocytes
leukocytes
platelets
all of the above
all of the above
Predict the outcome of an overdose of the hormone erythropoietin
the blood viscosity increases to levels that may induce heart attacks or strokes
the oxygen carrying-carrying capacity remains unchanged despite elevated red blood cell counts
red blood cell counts remain unchanged, but the number of reticulocytes increases
blood viscosity levels decrease while oxygen-carrying capacity increases
the blood viscosity increase to levels that may induce heart attacks or strokes
What response would you expect after traveling to high altitude for two weeks
blood levels of oxygen would remain depressed for the duration
a surge in iron release from the liver would occur
the kidneys would secrete elevated amounts of erythropoietin
there would be no change in blood composition
the kidneys would secrete elevated amounts of erythropoietin
If a patient had pernicious anemia, the inability of the body to absorb vitamin B12, the patient
would have reduced blood iron levels
would have a decreased number of red blood cells
would have increased levels of hemoglobin
would not experience any effects on red blood cells
would have a decreased number of red blood cells
An elevated neutrophil count would be indicative of
an allergic reaction
a cancer
an acute bacterial infection
a parasitic infection
an acute bacterial infection
Antihistamines counter the actions of which white blood cells
neutrophils
lymphocytes
basophils
eosinophils
basophils
Leukemia is a general descriptor for which of the following disorders
an abnormally low white blood cell count
overproduction of abnormal leukocytes
elevated counts of normal neutrophils
overproduction of abnormal erythrocytes
overproduction of abnormal leukocytes
A ____ is the progenitor of platelets
thrombopoietin
thrombocyte
megakaryocyte
thrombocytoblast
megakaryocyte
Why don’t platelets form plugs in undamaged vessels
platelets aren’t formed until vessel damage occurs
only contact of platelets with exposed collagen fibers and von Willebrand factor causes them to be sticky and form plugs
plugs do form but are removed by macrophages
platelets don’t form plugs; it is the megakaryocytes that form the plugs
only contact of platelets with exposed collagen fibers and von Willebrand factor causes them to be sticky and form plugs.
Activation of the extrinsic pathway of coagulation requires exposure of the blood to
collagen
tissue factor III
prothrombin activator
serotonin
tissue factor III
Why doesn’t a clot fill the entire vasculature system once it has started forming
rapid blood flow washes away and dilutes activated clotting factors
thrombin is inactivated by antithrombin III if it enters the general circulation
Both 1 and 2 occur
neither 1 or 2 occurs
both 1 and 2 occur
An injectable heparin medication might be prescribed for a patient who
is at risk for embolism
has thrombocytopenia
is a hemophiliac
has a deficiency in a clotting factor
is at risk for embolism
The presence of intercalated discs between adjacent cardiac muscle cells causes the heart to behave as a
single chamber
contractile myofibril
desmosome
functional syncytium
functional syncytium
Cardiac muscle cells have several similarities with skeletal muscle cells. Which of the following is not a similarity
the cells are each innervated by a nerve ending
the cells store calcium ions in the sarcoplasmic reticulum
the cells contain sarcomeres
the cells become depolarized when sodium ions enter the cytoplasm
the cells are each innervated by a nerve ending
The plateau portion of the action potential in contractile cardiac muscle cells is due to
an increased potassium permeability
an influx of calcium ions
an influx of sodium ions
exit of calcium ions from the sarcoplasmic reticulum
the influx of calcium ions.
The stimulus for the heart’s rhythmic contractions comes from
intercalated discs
acetylcholine
a neuromuscular junction
a pacemaker potential
a pacemaker potential
In a normal heart which of the following structures is responsible for setting the heart’s pace
sinoatrial node
atrioventricular node
atrioventricular bundle
purkinje fibers
sinoatrial node
Predict the nature of an ECG recording when the atrioventricular node becomes the pacemaker
there would continue to be a normal sinus rhythm
the P wave would be much larger than normal
the rhythm would be much slower
the T wave would be much smaller than normal
the rhythm would be slower
Which heart abnormality has no P waves on an otherwise normal ECG
second-degree heart block
ventricular fibrillation
aortic fibrillation
junctional rhythm
junctional rhythm
A heart murmur would be detected when blood is heard flowing from the ____ to the ____ through the ____
right atrium; right ventricle; tricuspid valve
right atrium; left atrium; tricuspid valve
left ventricle; left atrium; mitral valve
left atrium; left ventricle; mitral valve
left ventricle; left atrium; mitral valve
The “lup-dup” heart sounds are produced by
the walls of the atria and ventricles slapping together during a contraction
the blood hitting the walls of the ventricles and arteries respectively
the closing of the atrioventricular valves (lub) and the closing of the semilunar valves (dup)
the closing of the semilunar valves (lub) and the closing of the atrioventricular valves (dup)
the closing of the atrioventricular valves (lub) and the closing of the semilunar valves (dup)
Atrial systole occurs ____ the firing of the sinoatrial node
before
after
simultaneously with
alternately with
after
The majority (80%) of ventricular filling occurs
during late ventricular diastole
passively through blood flow alone
with atrial systole
both a and b
passively through blood flow alone
Cardiac output is determined by
heart rate
stroke volume
cardiac reserve
both a and b
both a and b
Predict what would happen to the end systolic volume (ESV) if contraction force were to increase
it would decrease
it would increase
it would remain constant
ESV is not affected by contraction force
it would decrease
Your heart seems to “pound” after you hear a sudden loud noise. This increased contractility is
because vagal nerve impulses arrive faster at the heart
because when a gasp of surprise is emitted, the Frank-Starling law of the heart is evident
due to norepinephrine causing threshold to be reached more quickly
because acetylcholine release is inhibited
due to norepinephrine causing threshold to be reached more quickly
What is the nature of acetylcholine’s inhibitory effect on heart rate
acetylcholine induces depolarization in the sinoatrial node
acetylcholine causes closing of sodium channels in the sinoatrial node
acetylcholine causes opening of fast calcium channels in contractile cells
acetylcholine causes opening of potassium channels in the sinoatrial node, thereby hyperpolarizing it
acetylcholine causes opening of potassium channels in the sinoatrial node, thereby hyperpolarizing it
Of the following blood vessel components which is the most critical in regulating systemic blood pressure
tunica intima
tunica media
tunica externa
venous valves
tunica media
An increasing lumen diameter is termed ____ and occurs when smooth muscle ____
vasodilation; relaxes
vasodilation; contracts
vasoconstriction; relaxes
vasoconstriction; contracts
vasodilation; relaxes
Of the following vessel types, which conduct blood toward the heart, regardless of oxygen content
arteries
arterioles
capillaries
veins
veins
Of the following vessel types which are responsible for the exchange of gases and nutrients with tissues
arteries
arterioles
capillaries
veins
capillaries
Some of the least permeable capillaries are found in the ___ while some of the most permeable capillaries are found in the ____
kidney; brain
intestine; muscles
bone marrow; brain
brain; bone marrow
brain; bone marrow
Predict the change in peripheral resistance as blood vessel diameter increases
peripheral resistance decreases
peripheral resistance increases
peripheral resistance remains unchanged
peripheral resistance is constant in humans
peripheral resistance decreases
Pulse pressure disappears by the time blood reaches capillary beds because
the elastic arteries are too stretchy
veins are too thin to accommodate the pulse pressure
diastole lasts longer than systole
the muscular arterioles do not exhibit elastic rebound
the muscular arterioles do not exhibit elastic rebound
What effect does prolonged standing in one position have on blood flow
it causes blood pooling and a slowing of blood flow
it causes a compensatory increase in arterial pressure
it causes a sharp decrease in heart rate
it causes a sharp decrease in respiratory rate
it causes blood pooling and a slowing of blood flow
What is the major factor controlling stroke volume during resting periods
sympathetic input
parasympathetic input
venous return to the heart
peripheral resistance changes
venous return to the heart
Predict what might happen to peripheral resistance in arterioles supplying skeletal muscle when pH levels drop
vasoconstriction in vessels supplying skeletal mucle
vasodilation in vessels supplying digestive viscera
vasodilation in vessels supplying skeletal muscle
no change in the skeletal muscle vessels
vasodilation in vessels supplying skeletal muscle
Baroreceptors detect changes in
blood O2 levels
stretch in arterial walls
blood CO2 levels
blood H+ levels
stretch in arterial walls
The primary mechanism driving filtration in capillary beds is
diffusion
capillary osmotic pressure
hydrostatic pressure of the interstitial fluid
hydrostatic pressure within the capillaries
hydrostatic pressure within the capillaries
Capillary colloid osmotic pressure created by ____ tends to ____
blood volume; push fluids out of the capillary
nondiffusable plasma proteins; draw fluids into the capillary
interstitial fluid; draw fluids out of the capillary
proteins in the interstitial fluid; push fluids into the interstitial fluid
nondiffusable plasma proteins; draw fluids into the capillary
Which of the following would cause vascular shock
anaphylaxis
vomiting
extensive burns
acute hemorrhage
anaphylaxis
Lymphatic capillaries owe their permeability to the presence of
an open end that siphons fluid from the interstitial fluid
minivalves in their walls
tight junctions between adjacent cells
proteins in the lymph fluid
minivalves in their walls
Which of the following contribute (s) to the flow of lymph through the lymphatic vessels
the pumping of the heart
the milking action of skeletal muscle contraction
pressure changes in the thorax that result from breathing
both 2 and 3
both 2 and 3
____ can enter lymph capillaries
bacteria
large proteins
interstitial fluid
all of the above
all of the above
The ___ is the largest lymphoid organ
lymph node
spleen
thymus
tonsil
spleen
The thymus is important for
T lymphocyte maturation'
removal of foreign antigens
B lymphocyte maturation
secretion of hormones that promote B lymphocyte immunocompetence
T lymphocyte maturation.
Which of the following act as the first line of defense against foreign pathogens
skin
synovial membranes
mucous membranes
1 and 3
1 and 3
Which of the following is not a mechanical barrier to pathogen invasion
mucus
tears
saliva
interferon
interferon
Macrophages are derived from
megakaryocytes
monocytes
T lymphocytes
plasma cells
monocytes
The basic mechanism employed by complement to fight bacterial infections is
antibody production
fever elevation
bacterial cell membrane lysis
antiviral protein synthesis
bacterial cell membrane lysis
The process of attaching complement proteins to the bacterial cell wall to enhance phagocytosis is called
optimization
MAC attachment
complement activation
opsonization
opsonization
What would be the body’s response if the hypothalamus detected pyrogens
an increase in body temperature set point
mobilization of lymphocytes from the bone marrow
increased sweating to lower body temperature
complement inhibition
an increase in body temperature set point
The presence of ____ proteins makes it possible for our immune system to differentiate between our cells and those that are foreign
antigenic determinant
MHC
hapten
antibody
MHC
The adaptive immune system involves three major cell types: antigen presenting cells, T cells, which constitute ____ immunity, and B cells which govern ____ immunity
nonspecific; specific
antigenic; allergenic
MHC; MAC
cell-mediated; humoral
cell-mediated; humoral
____ become antigenic if they attach themselves to larger proteins
haptens
antigenic determinants
pyrogens
MHC proteins
haptens
Lymphocytes are educated within primary lymphoid organs. B cells are educated in the ____ while T cells are educated in the ____
bone marrow; thymus
thymus; bone marrow
bone marrow; bone marrow
thymus; thymus
bone marrow; thymus
During clonal selection of B cells, those B cells with complementary membrane receptors to the invading antigen will differentiate into ____ cells
humoral
clonal
plasma
T cells
plasma
Which of the following is not an antigen presenting cell
T lymphocytes
Macrophages
B lymphocytes
Dendritic cells
T lymphocytes
The basis of immunity is the presence of ____ cells
plasma
memory
clonal
humoral
memory
A patient has been immunized against chicken pox. What type of immunity is this
naturally acquired passive
artificially acquired passive
naturally acquired active
artificially acquired active
artificially acquired active
Of the following classes of antibodies, which can cross the placenta
IgG
IgA
IgM
IgD
IgG
Which of the following best describes an antibody’s mode of action
antibodies punch holes in bacterial cell membranes
antibodies immobilize antigens and mark them for destruction
antibodies bind to antigens and transport them to the liver for excretion
antibodies secrete antiviral proteins
antibodies immobilize antigens and mark them for destruction
These cells are responsible for tissue graft rejection
memory cells
regulatory cells
Plasma cells
Cytotoxic T cells
Cytotoxic T cells