During the isovolumic phase of ventricular systole
the atrioventricular valves and semilunar valves are closed
Edema can be caused by
-obstruction of the lymph nodes by parasites or cancerous cells.
-heart failure
-inadequate lymph drainage
-increased capillary hydraulic pressure
Several blood- borne chemicals after the constriction and dilation of arterioles. Which is not pared correctly
histamine- vasodilation
sumatriptan- vasoconstriction
epinephrine- vasoconstriction with alpha receptors
kinins- vasoconstriction
SEROTONIN- VASOCONSTRICTION
The neural pathway from the spinal cord to the largest tissue has two neurons, the preganglionic neuron and the postganglionic neuron
True for both sympathetic and parasympathetic divisions.
Most preganglionic neurons originate in the thoracic and lumbar regions of the spinal cord
True only for sympathetic division
Some axons leave the CNS in either cranial nerve IX (the glossopharyngeal nerve) or X (the vagus nerve)
True only for parasympathetic division
The cell bodies of preganglionic neurins are found either in the brain stem or in the sacral region of the spinal cord
True only for parasympathetic division
Which neurons release acetylcholine at the neuroefftor synapse?
The parasympathetic division
The targets include smooth muscle,cardiac muscle, many exocrine glands, a few endocrine glands, and some adipose tissue
Both sympathetic and parasympathetic divisions.
One of the major nerves of the division is the vagus nerve
Parasympathetic division
The ganglia are found in a chain that runs close to the spinal cord or along the descending aorta
Sympathetic division
Realeases norepinephrine at the neuroeffetor synapse
Sympathetic division
Contains cholinergic neurons
True for both Symapathetic and parasympathetic divisions
Important during stress or emergencies (fight or flight)
Sympathetic division
Dominates during resting and digesting activities
parasympathetic division
Pathways are always excitatory, never inhibitory
Flase for both sympathetic and parasympathetic divisions
As blood vessel diameter decreases
Friction increases
Flow decreases
Resistance increases
During the cardiac cycle
The QRS complex of the ECG precedes the increase in ventricular pressure
The lightest color bands of the sacromere, occupied only by thin filaments
I Band
The darkest band, with the most overlapping filaments, its abbreviation ferives from its property of scattering light unevenly
A Band
The structures that serve as the attachment site for the thin filaments and mark the boundaries for one sacromere
Z disc
Strech- sensitive mechanoreceptors know as _____ are located in some artery walls
Baroreceptors
Increased levels of carbon dioxide in the blood will result in
decreased heart rate
Compared to blood capillaries, lymph capillaries
Are frequently irregular in shape.
Are larger in diameter.
Have no basement membrane.
Have walls of endothelial cells that overlap like shingles
At the conclusion of the power stroke
The myosin head is tightly bound to actin.
Actin has been moved toward the M line
Inorganic phosphate has been released from the myosin
ADP is released from the myosin head
(all these are correct)
A hemoglobin molecule is composed of
four protein chains and four heme groups
A condition in which the hematocrit is elevated and the blood volume is normal is
polycythemia
Blood flow to a tissue will increase if the
level of carbon dioxide at the tissue increases
Platlets function in
Forming temporary patches in injured areas.
Transporting chemicals important for clotting.
Initiating the clotting process.
Contraction after clot formation
(All the above are true)
Under normal circumstances, aged and damaged erythrocytes are broken down by the
spleen
Each of the following conditions would increase heart rate except one.
-Activation of cAMP in heart muscle.
-Increased levels of epinephrine in the interstitial fluid surrounding the myocardium.
-INCREASED PARASYMPATHETIC STIMULATION OF NODAL FIBERS.
-Increased symapthetic stimulation of nodal fibers.
-Increased permeability
In the body, the bones act as ___ whereas the joints form the ___, so that the muscles attached to the bones can create force when they contract
Levers/ Fulcrums
The scientist credited with the foundations of our understanding of the circulatory system is
William Harvey
The lymphatic system
-has lymph nodes positioned strategically where immunologically active cells interact with the lymph.
-relies on the skeletal muscle pump to circulate lymph fluid.
-does not have its own pump like the heart
-empties the lymph vessels into the veins near t
Sympathetic stimulation increases the heart rate by
increasing ion influx thus increasing the rate of depolarization
These factors help prevent clot formation in intact blood vessles
-collagen is hidden unless a vessel is damaged, attracting platelets and promoting their adhesion.
-endothelial cells have prostacyclin in their membranes, which block platelet adhesion
-intact endothelial cells release nitric ovide, which blocks platlet
In a condition known as "complete heart block", what happens?
Electrical signals from the SA node never reach the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles
Put these events in the correct chronological order
1.Acetylcholine binds to receptors on the motor end plate
2.Chemically regulated ion channels open, causing depolarization.
3.End plate potentials trigger action potentials
4.Transverse tubules convey potntials into the interior of the cell
5.Ca2+ is rele
A single contraction- relaxation cycle in a skeletal muscle fiber is known as
a twich
The vessel type that is the main site of variation is resistance in the systemic circulation, and that contibutes more than 60% of the total resistance, are the
arterioles
As blood vessel length increases
Flow decreases and resistance increases
Which statement is true?
1. The thin actin filaments slide along the thick myosin filaments as they move toward the M line in the center of the sacromere.
2.The sacromere shortens, the two Z discs at each end move closer together, and the I band and H zon
All statements are true
The common pathway of coagulation begins with
The activating of a clotting factor that converts prothrombin to thrombin
Each of the visceral reflexes is coordinated by the medulla except one.
-coughing relfex
-vomiting reflex
-pupillary reflex
-swallowing reflex
-cardioinhibitory reflex
Pupillary reflex
The purpose of transverse tubules is to
rapidly conduct action potentials to the interior of the muscle fiber.
The difference between the systolic and diastolic pressures is
Pulse pressure
Which of the following is greater?
-blood pressure when the peripheral vessels dilate
-blood pressure when the peripheral vessels constrict
Blood pressure when the peripheral vessels constrict
In order to cause vasodilationof most vascular smooth muscle
Sympathetic stimulation is removed
The driving force of blood flow is a(n)____gradient
Pressure
The catecholamines, epinephrine and norepinephrine
-Stimulate a stringer contraction from cardiac muscle cells
-can increase both the heart rate and the strength of the contraction
-shorten the duration of the cardiac contraction, allowing the cells to contract sooner.
(all are true)
Dual innervation" refers to an organ receiving
Both sympathetic and parasympathetic nerves
The importance of the plateau phase of the action potential of myocardial cells is in
Preventing Tetanus
During a viral infection you would expect to see increased numbers of
Lymphocytes
A contraction that generates force and moves a load is known as ____, whereas one that generates force without movement is known as ____
Isotoinc/Isometric
The AV node is important because it
-Delays the transmission of the electrical impulses to the ventricles in order for the atria to finish contracting
-Directs electrical impulses from the atria to the ventricles
The volume of blood ejected from each ventricle during a contraction is called
stroke volume
The flattening of the action potential of myocardial contractile cells called the plateau phase is due to a combination of ____K+ permeability and ____Ca2+ permeability
decreasing/increasing
When red blood cells die, many of their components are recycled. Which is not correct?
-Bilirubin is excreted only by the kidneys
-The liver metabolizes bilirubin into bile, which enters the digestive tract and may leave the body with the feces
-Heme is c
Bilirubin is excreted only by the kidneys
I-f channels are permeable to
Na+ and K+
Which statement is true?
-Each myosin molecule acts as an enzyme which binds ATP and releases its energy
-Myosin is a motor protein that converts the chemical bond energy of ATP into the mechanical energy of motion
-The energy released by ATP produces the
All are true
When a quantity is expressed as "4 cm/sec" what is being described is the
velocity of flow
According to Starlings Law of the heart, the cardiac output is directly related to the
venous return
Nicotinnc receptors
-are found on skeletal muscles at the neuromuscular junction
-bind ACh and open monovalent cation channels
Asynchronous recruitment
-helps avoid fatigue during sustained muscle contractions
-refers to different motor units taking turns maintaining muscle tension
-makes an entire muscle seem to contract smoothly
When the heart is in fibrillation
Effective pumping of the ventricles ceases because the myocardial cells fail to work as a team, and the brain cannot get adequate oxygen
In adults, erythropoises primarily takes place in
red bone marrow
____ capillaries are veryporous and allow high volumes of fluids to pass through them, whereas ____ capillaries consist more tightly joined cells that allow a high degree of selectivity of materials to pass
Fenestrated/ continuous
Hypoxia refers to low levels of
Oxygen
The period of time during which the sacromeres return to their resting length is referred to as
the relaxation phase
Put these neurons and myofibers in order of recruitment from first to last
1.Lowest threshold neurons
2.Fatigue resistant slow twich fibers
3. highest threshold neurons
4.Fatigue resistant oxidative fast twich fibers
5.Highest threshold neurons
6.Glycolytic fast twich fibers
A unique aspect of hematopoises is that
White blood cell development varies with the specific needs of the body
The rapid depolarization phase of the action potentials of myocardial contractile cells is due to which ions?
Na+
The phase cardiac cycle refers to
-diastole
-the events that occur from the start of one contraction through relaxation of the heart
-systole
-the electrical events that occur from the start of one contraction through relaxation of the heart
The function of the pericardial fluid is to
reduce friction between the heart and pericardium
The integrating center for neural control of blood pressure resides in the
Medulla oblongata
Put these stages in the correct order from least to most mature
1.Commited stem cells
2.erythroblasts
3.reticulocyte
4.erythrocyte
Type of shock that can be caused by immune reactions, such as allergy to penicillin or bee stings
Anaphylactic Shock
Type of shock associated with failure of the heart to maintain normal cardiac output, this can be caused by heart failure or blood pressure problems
Cardiogenic Shock
Type of shock caused by infections or conditions that release bacterial toxins, this could be started by an abscessed tooth or other seemingly minor problems
Septic Shock
Type of shock caused by decreased circulating blood volume, this can be brought on through trauma that leads to blood loss
Hypovelmic Shock
Which of the following situations could result in anemia?
-Hemmorage
-disease of red bone marrow
-dietary deficiancy of iron
-lack of vitamin B12 in the diet
All the above
Compared to arteries, the velocity of flow of the blood through the capillaries is
much slower
Perfusion pertains to
Maintance of adequate blood flow through an organ
Which statement regarding capillary exchange is false?
-Tissues with higher metabolic rates require more oxygen and nutrients, therefore they have more capillaries per unit area
-The total exchange surface area of the capillaries is the size of a basketba
The toatl exchange area of the capillaries is the size of a basketball court
____ invlolves a complex sequence of steps leading to the conversion of fibrinogin to fibrin
Coagulation
Parasympathetic stimulation slows the heart rate by
-increasing ion influx thus increasing the rate of depolarization
-decreasing the permiability only to Ca2+
Summation in a single muscle fiber means that
- the fiber increases the frequency of contraction
-the fiber increases the force of the contraction
The H zone contains
thick filaments
The intristic pathway of coagulation is activated by
the activation of proenzyme exposed to collagen
When acetylcholine is released into the neuromuscular junction
-action potentials are triggered, which lead to activation of the contraction cycle
-it binds to receptors which allow Na+ and K+ ions to cross the sarcolemma
-The muscle membrane depolarizes, creating an end-plate potential (EPP)
The f in I-f channels stands for
Funny
Each red blood cell is shaped as a bioconcave disk. This allows it to
-shrink or swell slightly in response to osmotic conditions
-change its shape to squeeze through narrow openings
The mean arteriol pressure (MAP) is important because
-it represents the driving pressure for blood flow
-it reflects the difference in time that systole lasts compared to diastole
The steep repolarization phase of the action potentials of myocardial contractile cells is due to which ion
K+
Each of the following factors will increase cardiac output except one.
-increased heart rate
-increased venous return
-increased force of ventricular contraction
-increased parasympathetic stimulation
-increased sympathetic stimualtion
Increased parasympathetic stimulation
The brief period of time between the end of the action potential in the muscle and the beginning of contraction is referred to as
The latent period
The process of fibrinolysis
dissolves clots