During the local inflammatory response, a lack of mast cells would result in
decreased capillary permeability.
Phagocytic cells include all of the following EXCEPT
lymphocytes
Which of the following processes can be activated by the complement system
_____________________________?
cytolysis, inflammation and opsonization
Opsonization is ____________________.
coating of a bacterium with antibody to make it more susceptible to phagocytosis
The sequence for the processing of proteins originating outside of the cell, is that they are broken into fragments and then _______________.
transported to the rough endoplasmic reticulum, fuse with a Golgi vesicle containing class II MHCs, and transported to the plasma membrane.
Foreign antigens presented on class I MHC molecules __________.
stimulate cell destruction by activated T-cells.
(T/F) Fragments of foreign proteins are antibodies.
False
(T/F) Viruses and self-proteins are examples of proteins produced inside of the cell.
True
On first exposure to antigen, T helper cells ______________.
become activated and increase in number.
Skin lesions due to hypersensitivity appear _______.
24 hours after second exposure to antigen.
(T/F) A hapten is an antigen that is capable of causing antibody production on its own.
False
(T/F) Delayed hypersensitivity is due to the effects of the humoral part of the immune system.
False
An IgE mediated hypersensitivity, which of the following are needed?
antigen presenting cells, B cells, IgE antibodies, and mast cells
Histamine, released by mast cells, leads to which of the following symptoms?
mucus secretion
(T/F) For a hypersensitivity response to occur, two bound IgE molecules on a mast cell must react with a specific antigen.
True
(T/F) Activated T helper cells produce cytokines, which stimulate B cells to proliferate and differentiate into plasma cells capable of producing IgE.
True
Foreign substances that elicit an immune response are termed _____.
antigens
Macrophages secrete ________ which then activates ________ .
interleukin-1 ; helper T cells
The human body makes __________.
millions of different types of cytotoxic T cells.
Helper T cells can stimulate the proliferation of cytotoxic T cells but not the proliferation of B
cells.
False
The secondary immune response to a previously encountered pathogen is swifter and stronger than the primary immune response.
True
Which of the following are needed for antibody production to occur with T cell dependent antigens?
antigen presenting cells, B cells and T helper cells
An antigen presenting cell presents antigen to a T helper cell _____.
on its surface on a class II MHC
A helper T cell becomes activated by a _____.
antigen presenting cell
(T/F) A helper T cell must become activated before it can stimulate a B cell to produce antibody.
True
(T/F) Protein is usually a T-cell dependent antigen.
True
Immune complexes consist of ________.
antigen plus antibody
Intermediate size complexes react with and activate ____
compements
In the presence of activated complement, neutrophils _____
degranulate and release enzymes that cause tissue damage
Most intermediate size antigen antibody complexes are removed by phagocytosis
False
After complement activation, basophils may degranulate causing vasodilation.
True
Antigens such as proteins have several different sites that can react with antibodies. These sites are called
epitopes
The most direct source of monoclonal antibodies are ________ cells.
hybridoma
Which of the following statements about monoclonal antibody production is true?
B cell + myeloma -> hydridoma
(T/F) A single monoclonal antibody can bind to several different sites on an antigen
False
(T/F) Monoclonal antibodies have applications in cancer therapy and diagnostic microbiology
True
What substance signals macrophages to destroy self-cells that have committed apoptosis?
phosphatidylserine
(T/F) Antigens are used to induce a passive immune response
False
(T/F) Both innate and adaptive immunity processes are necessary for local inflammation to function properly.
True
(T/F) The characteristic symptoms of local inflammation include redness, warmth, swelling, pain, and pus
True
Which of the following is an example of how active immunity is acquired?
The person produces antibodies in response to being injected with antigens.
A class-2 MHC molecule is used to present a foreign antigen to a
helper T lymphocyte.
(T/F) Interferons have diverse functions including inhibiting erythrocyte and adipose cell maturation
True
The ability of antibodies to promote phagocytosis is called
opsonization
Somatic motor neurons release the neurotransmitter _________ at the neuromuscular junction.
acetylcholine
Subunits of skeletal muscle cells that are composed of sarcomeres are called
myofibrils.
The specialized region of the sarcolemma at the neuromuscular junction is called the
motor end plate.
Which molecule blocks the myosin head from binding to actin in a relaxed muscle?
tropomyosin
What protein primarily makes up the thin filament?
actin
(T/F) Transverse tubules contain voltage-gated calcium channels that respond to membrane depolarization and are directly coupled to the calcium release channels in the sarcoplasmic reticulum.
True
Which of the following statements regarding cardiac muscle is true?
Intercalated discs contain gap junctions.
What are the swellings on autonomic nerves that release neurotransmitter to smooth muscle
called?
varicosities
The Ca2+ required for skeletal muscle contraction is released from the ________
sarcoplasmic reticulum
(T/F) The epimysium surrounds the individual muscle cells.
False
(T/F) Sarcomeres contain elastic titin filaments which help the muscles return to their resting length during muscle relaxation.
True
Skeletal muscle cells are multinucleated. This is called a/an
syncytium.
The inability of muscle cells to relax due to high frequency stimulation is termed
tetanus
Which of the following is not a function of the muscular system?
secretion
________ is characterized by continued attachment of myosin heads to actin filaments due to
a lack of ATP.
rigor mortis
What muscle structural and functional unit runs from Z disc to Z disc?
sarcomere
Each somatic motor neuron with all the muscle fibers it innervates is a
motor unit
If a muscle is repeatedly stimulated and allowed to relax between stimuli, the successive contractions will be stronger. This phenomenon, known as treppe, or staircase effect, is thought to be due to the accumulation of neurotransmitter in the neuromuscular cleft.
False
ATP in muscle contraction is needed for
attachment of myosin cross bridges to actin.
release of myosin cross bridges from actin.
pumping of Ca2+ back into the sarcoplasmic reticulum.
Cardiac action potentials usually originate in ______________ cells
pacemaker
Which of the following shortens in length during during skeletal muscle contraction?
I band
The movement of the troponin-tropomyosin complex requires
Ca2+
The _________ complex contains three proteins designated as the I, T, and C types.
troponin
(T/F) Summation occurs in muscle cells when stimulus frequency increases to produce a greater force contraction.
True
(T/F) Smooth muscle contraction requires the actions of myosin light chain kinase.
True
The staircase effect or _____ represents a warm up effect due to increasing intracellular calcium concentrations
treppe
An action potential enters a muscle cell ___
by the T-tubules.
What structures do the calcium ions bind to when muscle contraction is initiated?
the troponin molecule.
Cross bridges form between _________________.
the actin filaments and the myosin heads.
(T/F) An action potential introduced at the neuromuscular junction is propagated along the sarcoplasmic reticulum
False
(T/F) In response to an action potential entering the muscle cell, calcium ions diffuse from the sarcolemma into the sarcoplasm.
False
The sequence for smooth muscle contraction is...
increased cytosolic calcium, which binds to calmodulin in cytosol, complex binds with myosin light-chain kinase, which uses ATP to phosphorylate myosin cross-bridges, which
bind to actin filaments, resulting in contraction.
The sequence for skeletal muscle contraction is...
increased cytosolic calcium, which binds to troponin, which moves tropomyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in
contraction.
Which of the following statements is true concerning calcium ions?
in smooth muscle it binds with calmodulin.
(T/F) Smooth muscle and skeletal muscle fibers both have their contractions triggered by calcium ions.
true
(T/F) Both smooth muscle contractions and skeletal muscle contractions involve thin (actin) filaments sliding over the thick (myosin) filaments.
True
During contraction of a muscle, calcium ions bind to...
the troponin molecule.
The bond between the actin and myosin head is broken when...
an ATP molecule binds to the myosin head.
Energy is released when...
ATP is broken down into ADP and phosphate.
(T/F) The sequence of cross bridge formation and myofilament movement will be repeated as long as calcium ions are present.
True
(T/F) When cross bridges form and the muscle fibers contract, the actin myofilament slides past the myosin myofilament.
True
Each actin filament is composed of ___
two strands of actin molecules wrapped together.
As actin and myosin filaments slide past each other during muscle contraction
neither actin nor myosin filaments shorten.
Which of the following statements about the "heads" of the myosin molecules is TRUE?
they can attach to different sites on the actin filament
(T/F) Each myosin protein has a globular head that extends outward from the myosin filament.
True
(T/F) Unflexing of the myosin head requires ATP.
True
Muscle contraction is caused by
actin filaments sliding past myosin filaments.
(T/F) The H zones contain only myosin, while the I bands contain only actin
True
During muscle contraction the A band ______
remains the same and the I band narrows.
(T/F) In a contracting muscle the Z lines come closer together.
True
(T/F) In a relaxed muscle, the H zone is at its narrowest width.
False
A person who sprints for 45 seconds obtains most of their energy from
muscle glycogen.
What happens to the amount of muscle glycogen used for energy as exercise continues?
it decreases
Where are most plasma free fatty acids obtained from?
hydrolysis of stored fat
Prolonged immobility would ________
increase the risk of blood clot formation
Sickle cell disease is caused by
a mutation
Petechiae are a symptom of
thrombocytopenia.
In edema
tissues swell with fluid.
Diapedesis is
movements of white blood cells out of the circulation.
Pus is composed of
bacteria, white blood cells, and damaged cells.
The red blood cells of type AB blood have on their surfaces
antigens A and B.
A primary function of lymphocytes is to
act against foreign substances.
Which of the following elements is included in hemoglobin molecules?
Iron
Heme released from hemoglobin in aged red blood cells is decomposed in the liver into
iron and the bile pigment biliverdin, which is eventually converted to bilirubin.
As a result of starvation or a protein-deficient diet, blood protein concentration
decreases and water accumulates in tissue spaces.
A person with type AB blood can successfully receive blood from a person with type ___________ blood.
A, B, O
Describe the role of plasmin.
Breaks down fibrin, dissolving the clot
At what stage of erythopoiesis is the developing red blood cell released into the circulation?
reticulocyte
Which of the following is required for the formation of a blood clot?
Calcium
Fibrinogen
Vitamin K
What is the difference between serum and plasma?
Plasma contains fibrinogen; serum does not.
Nonprotein nitrogenous substances include
amino acids
urea
creatinine
The final step in the formation of a blood clot is
that thrombin converts fibrinogen to fibrin.
Prothrombin time is a blood test used to evaluate
extrinsic clotting mechanism.
A blood clot that forms abnormally in a blood vessel is a(n)
thrombus
Hematocrit is
the percent of red blood cells in a blood sample.
The release of tissue thromboplastin initiates
the extrinsic clotting mechanism.
Which is the correct sequence for differentiation of a red blood cell?
Name the enzyme that catalyzes the reaction that converts fibrinogen to fibrin
thrombin
Risk factors for deep vein thrombosis are
prolonged periods of staying still in one position
use of oral contraceptives or estrogen
dehydration
Chemicals released by damaged cells, white blood cells, and platelets act to attract white blood cells to the area. This attraction is called
positive chemotaxis
Blood platelets
form from megakaryocytes
release serotonin
number from 150,000 - 450,000 per microliter blood
Biliverdin and bilirubin are pigments that result from the breakdown of red blood cells. Biliverdin is ______ in color and bilirubin is ______ in color.
greenish; orange
Platelets are best described as
cytoplasmic fragments of cells.
Cyanosis is caused by an increased blood concentration of
deoxyhemoglobin.
Define hemostasis.
Process that stops bleeding
Erythroblastosis fetalis may occur in
a second Rh-positive fetus developing in an
Rh-negative woman.
(T/F) People who are Rh-negative will typically have anti-Rh antibodies in their blood.
False
The typical life span of a red blood cell is:
120 days
In leukemia
the blood has too many immature leukocytes
the person has lowered resistance to infection
the blood has too few platelets
Hydroxyurea treats sickle cell disease by
activating production of hemoglobin normally produced only in a fetus.
The risk of erythroblastosis fetalis occurs with:
Rh- mom and Rh+ fetus
What is a thrombocyte?
a platelet
Which of the following are most active as phagocytes?
