A&P 2, Exam 2
What is the main function of the pulmonary trunk?
It brings deoxygenated blood to lungs.
What is the largest artery in the body?
The aorta
The CO of an average human is what?
5.25 L per minute
Bloods flows through the heart in one direction: it is first sucked into the _______, sweeps from there to the _________, and surges out the ___________ and _________ at the base of the heart.
Blood flows through the heart in one direction: it is sucked into the ATRIA, sweeps from the atria to the VENTRICLES, and surges out the PULMONARY TRUNK and AORTA at the base of the heart.
Cardiac output can be calculated from what relationship or equation?
CO = SV x HR
Immediately after the second heart sound ("dub"), the _________ are filling with blood, and the ________ are empty.
Immediately after the second heart sound ("dub"), the ATRIA are filling with blood, and the VENTRICLES are empty.
_________ filter lymph.
Lymph nodes
One complete sequence of filling and pumping blood is called a ________, or _______.
One complete sequence of filling and pumping blood is called a CARDIAC CYCLE, or HEARTBEAT.
What directs the flow of blood through the heart?
The opening and closing of valves
The second heart sound is heard during which phase of the cardiac cycle? a. ventricular filling b. isovolumetric relaxation c. ventricular ejection d. isovolumetric contraction
b. isovolumetric relaxation
Which tunic of an artery contains endothelium? a. tunica media b. tunica intima c. tunica externa d. basement membrane
b. tunica intima
Capillaries, the link between arteries and veins, are the sites where molecules are exchanged between ________ & _________.
blood & interstitial fluid
As cardiac output and blood volume go up, so does _________.
blood pressure
The 4 heart valves open and close in response to differences in _________ on their two sides.
blood pressure
What is the most characteristic function of arteries?
blood transport away from the heart
What is the most characteristic function of veins?
blood transport towards the heart
_________ form a tubular network throughout the body that allows blood to flow from the heart to every body cell and then back to the heart.
blood vessels
The portion of the intrinsic conduction system located in the interventricular septum is the: a. SA node b. Purkinje fibers c. bundle of His and its branches d. AV node e. interatrial pathway
c. bundle of His and its branches
The P wave of a normal electrocardiogram indicates ________. a. ventricular depolarization b. atrial repolarization c. ventricular repolarization d. atrial depolarization
d. atrial depolarization
The period of relaxation in the heart is called ________.
diastole
Throughout the 3 phases of the cardiac cycle, the muscles of the atria & ventricles contract and relax, and the heart valves open & close in response to....
differences in blood pressure.
Another term for SA node is the ___________.
pacemaker
What are the three phases of the cardiac cycle?
1. Atrial systole (0.1 sec) 2. Ventricular systole (0.3 sec) 3. Atrial & Ventricular Diastole (0.4 sec)
List the following in increasing blood pressure: arterioles, arteries, aorta, and capillaries.
1. Capillaries - lowest blood pressure 2. Arterioles 3. Arteries 4. Aorta - highest blood pressure
7 factors that lead to an increase in cardiac output (CO) by influencing either heart rate or stroke volume.
1. Epinephrine 2. Thyroxine 3. Fear 4. Exercise 5. Low blood pressure 6. Fever 7. Activation of the sympathetic nervous system
The heart's rhythm of contraction is controlled by the _____________, often called the pacemaker.
sinoatrial node (SA node)
The walls of arteries and veins have 3 layers called ______.
tunics
Blood pressure in the arterial system is influenced by... (hint: there are 3)
-Cardiac output -Blood Volume -Peripheral resistance of the arterial system
The body needs special adaptations to help return blood to the heart. What are the four main ones?
-Large diameter in the lumens -One-way valves which prevent backflow -Contracting skeletal muscles that press against veins to force blood through these one-way valves -Operation of the "respiratory pump"
What are the 4 factors that effect venous return?
-large diameter lumen -one-way valves -pressure changes accompanying the respiratory cycle (breathing) -skeletal muscles
___________ experience the full force of the heart's pumping action.
Arteries
Is it the arteries, capillaries, or veins that are exposed to the highest blood pressure?
Arteries (because they experience the full force of the heart's pumping action)
Which has the thickest tunica media? (Hint: Arteries, Capillaries or Veins)
Arteries (because they have to be stronger and more elastic)
Arteries contain oxygen-_______, CO2-________ blood.
Arteries contain oxygen-rich, CO2-poor blood.
The aortic and pulmonary semilunar valves are composed of _____(#) pocket-like cusps.
3
A normal adult heart rate can vary from _____ to _____ beats per minute.
A normal adult heart rate can vary from 60 to 100 beats per minute.
What do the walls of capillaries consist of?
A single layer of simple squamous epithelial cells & a basement membrane.
The first heart sound ("lub") is caused by closure of the ___________.
AV (atrioventricular) valves
The valves that lie between the atria and ventricles are called ________.
AV valves (Atrioventricular valves)
Which of the following is not part of the conduction system of the heart? a. AV valve b. SA node c. bundle of His d. AV node
a. AV valve
True or False: By the time blood is passing through the arterioles, surges are apparent.
False; By the time blood is passing through the arterioles, surges are NO LONGER apparent.
True or False: The tunica externa of veins is generally thinner than it's tunica media.
False; The tunica externa of veins is generally THICKER than it's tunica media.
True or False: In both the pulmonary and systemic capillaries, water moves into the plasma only.
False; Water moves both into and out of the plasma
__________ generate blood pressure, the fluid pressure that blood exerts against vessel walls.
Heart contractions
Cardiac output (CO) depends on two factors, which are...
Heart rate & Stroke volume
In both pulmonary and systemic capillaries (from arteriole to venule), amino acids and glucose leave the ________ to enter and feed both the ________ and _______.
In both pulmonary and systemic capillaries (from arteriole to venule), amino acids and glucose leave the BLOOD to enter and feed both the CAPILLARY EPITHELIAL CELLS and ALVEOLAR EPITHELIAL CELLS.
In humans, the _____(right or left) side of the heart pushes blood through the pulmonary circuit so that it can be oxygenated in the _____.
In humans, the RIGHT side of the heart pushes blood through the pulmonary circuit so that it can be oxygenated in the LUNGS.
In the heart, the muscles of the _______ provide the motive force, the ______ direct the flow, and the ________ convey blood to and from body tissues.
In the heart, the muscles of the CHAMBER WALLS provide the motive force, the VALVES direct the flow, and the GREAT VESSELS convey blood to and from body tissues.
Abnormal heart sounds are called _________.
Murmurs
Does activation of the vagus nerves lead to an increase in cardiac output by influencing heart rate or stroke volume?
No.
Does high blood pressure lead to an increase in cardiac output by influencing heart rate or stroke volume?
No.
Normal resting blood pressure is 120 mmHg/80mmHg. The higher number is the systolic pressure, the pressure recorded in an _______(artery or vein) when the ______ (L/R) ventricle _________ (contracts or relaxes).
Normal resting blood pressure is 120 mmHg/80mmHg. The higher number is the systolic pressure, the pressure recorded in an ARTERY when the LEFT ventricle CONTRACTS.
Normal resting blood pressure is 120 mmHg/80mmHg. The lower number is the diastolic pressure, the pressure recorded in an _______(artery or vein) when the _____(L/R) ventricle _________(contracts or relaxes).
Normal resting blood pressure is 120 mmHg/80mmHg. The lower number is the diastolic pressure, the pressure recorded in an ARTERY when the LEFT ventricle RELAXES.
Electrical impulses generated from the SA node spread through the heart via ________ that coordinates the events of the cardiac cycle.
a nodal tissue pathway
_________ of the arterial system is largely a function of the diameter of small arteries and arterioles.
Peripheral resistance
__________ are found in the wall of the GI tract.
Peyer's patches
The __________ exits from the right ventricle and carries deoxygenated blood to the lungs.
Pulmonary trunk
In system circulation, CO2 and other cellular wastes, like ammonia, move from the interstitial fluid to the blood, which delivers them to what two systems for disposal?
Respiratory & Excretory Systems
Automaticity is due to the spontaneous electrical activity of the ________.
SA node.
The second heart sound ("dub") is caused by closure of the ____________.
Semilunar valves
What's the name for the valves that are situated between the ventricles and their attached great vessels?
Semilunar valves
What is the main function of the interatrial septum?
Separates the left & right atria
________ blood pressure is the maximum pressure that is produced in the arteries during the systolic phase of the heart.
Systolic
When looking at the two numbers in blood pressure (ex: 120 mm Hg/80 mm Hg), what do the two numbers indicate?
Systolic pressure/Diastolic pressure (ex: 120 mm Hg/80 mm Hg)
The _________ sucks blood upward toward the heart as a result of pressure changes induced in the thoracic cavity by breathing.
The "respiratory pump"
The AV valves are supported by strong collagen cords called chordae tendineae ("heart strings"), which are anchored on __________ protruding from the ________.
The AV valves are supported by strong collagen cords called chordae tendineae ("heart strings"), which are anchored on PAPILLARY MUSCLES protruding from the VENTRICULAR WALLS.
The _________ of the tunica media of arteries allows them to stretch and recoil, while the _________ allows them to constrict and dilate.
The ELASTIN of the tunica media of arteries allows them to stretch and recoil, while the SMOOTH MUSCLE allows them to constrict and dilate.
The _________ is the largest o all the chambers and forms the heart _______.
The LEFT VENTRICLE is the largest of all the chambers and forms the heart APEX.
The ____ side of the heart pumps oxygenated blood to the ________ via the systemic circuit.
The LEFT side of the heart pumps oxygenated blood to the ENTIRE BODY via the systemic circuit.
What valve guards the base of the aorta?
The aortic semilunar valve
The atria have much ________ (thicker or thinner) walls than the ventricles and are much ________ (larger or smaller).
The atria have much THINNER walls than the ventricles and are much SMALLER.
What term describes the subendothelial layer composed of connective tissue in the tunica intima that supports the endothelium?
The basement membrane
After blood is moved from the arterial end of a capillary to the venule end, what happens to the pressure in the large veins?
The blood pressure in these large veins falls to zero!
Which blood vessel is the standard point of reference when measuring blood pressure?
The brachial artery
The circulatory system transports the toxic by-product ammonia to the _______(hint: organ), where it is combined with CO2 to form _______ and the expelled by the ______(hint: organ) in ______.
The circulatory system transports the toxic by-product ammonia to the LIVER, where it is combined with carbon dioxide to form UREA and then expelled by the KIDNEYS in URINE.
The crucial exchange of substances required for cellular metabolism takes place through the ___________, which allows cells of the various tissues to take up ________ & ________ and to expel ________ & ________.
The crucial exchange of substances required for cellular metabolism takes place through the CAPILLARY ENDOTHELIUM, which allows cells of the various tissues to take up OXYGEN & NUTRIENTS and to expel CARBON DIOXIDE & WASTES.
Define blood pressure.
The force blood exerts against vessel walls
The heart chambers that have just been filled when you hear the first heart sound ("lub") are the __________, and the chambers that have just emptied are the __________.
The heart chambers that have just been filled when you hear the first heart sound ("lub") are the VENTRICLES, and the chambers that have just emptied are the ATRIA.
The human heart is a cone-shaped muscular pump located in the ________ cavity of the ________ between the _______ and beneath the ________.
The human heart is a cone-shaped muscular pump located in the MEDIASTINAL cavity of the THORAX between the LUNGS and beneath the STERNUM.
An internal partition separates the right and left sides of the heart. This is called the _________ if it is between the atria, and it's called the _________ if it is between the ventricles.
The internal partition separates the right and left sides of the heart. This is called the INTERATRIAL SEPTUM if is between the atria, and it's called the INTERVENTRICULAR SEPTUM if it is between the ventricles.
The left AV valve, the ________ aka _______, has _____(#) flexible cusps.
The left AV valve, the BICUSPID aka MITRAL, has 2 flexible cusps.
Why is the blood pressure so low in veins?
The pressure has been greatly reduced by the blood's long journey from the heart.
What valve guards the base of the pulmonary trunk?
The pulmonary semilunar valve
The right AV valve is the _______ valve, & the left AV valve is the _______ valve. (hint: bicuspid/tricuspid)
The right AV valve is the TRICUSPID valve & the left AV valve is the BICUSPID valve.
The right AV valve, the _________, has _____(#) flexible cusps.
The right AV valve, the TRICUSPID, has 3 flexible cusps
What is the largest lymphatic organ?
The spleen
What lymphatic organ is known for removing aged & defective red blood cells?
The spleen
The vessels of the _________ & _________ circuits carry blood to the tissues of the entire body.
The vessels of the PULMONARY & SYSTEMIC circuits carry blood to the tissues of the entire body.
The walls of capillaries are ______ (thin or thick).
Thin
What is the main function of the AV valves?
To prevent backflow of blood into atria
What is the main function of the semilunar valves?
To prevent backflow of blood into ventricles
True or False: An obstruction in the superior vena cava would decrease the flow of blood from the head and neck to the heart.
True
True or False: Blood pressure at the arterial end of a capillary is just high enough to move the blood to the venule end.
True
True or False: Capillaries have such a small lumen that red blood cells must squeeze through in a single file.
True
True or False: During exercise, CO can increase 5-fold.
True
True or False: Each blood vessel consists of a layered wall surrounding a central blood-containing space, or lumen.
True
True or False: In both the pulmonary and systemic capillaries (from arteriole to venule), ammonia is deposited into the blood.
True
True or False: The CO of an average human is the total volume of blood in the human body.
True
True or False: The heart will beat without input from the nervous system and will continue to beat, even outside the body, as long as its cells are alive.
True
What is the outer layer of the walls of arteries or veins called?
Tunica externa
What layer of arteries and veins contains connective tissue with collagen fibers?
Tunica externa
Which layer in veins is the heaviest?
Tunica externa
What is the inner layer of the walls of arteries and veins called?
Tunica intima
What layer of arteries and veins consists of specialized simple squamous epithelium (aka endothelium) that lines all blood vessels and the endocardium of the heart.
Tunica intima
What is the middle layer of the walls of arteries and veins called?
Tunica media
What layer of arteries and veins contains circularly arranged smooth muscle and elastic fibers?
Tunica media
Veins contain oxygen-_______, CO2-________ blood.
Veins contain oxygen-poor, CO2-rich blood.
Veins have _______ (thicker or thinner) walls than arteries, and their lumens are ________ (larger or smaller), accommodating a _________ (larger or smaller) volume of blood.
Veins have THINNER walls than arteries, and their lumens are LARGER, accommodating a LARGER volume of blood.
What great vessel(s) brings deoxygenated blood from the body to the right atrium?
Vena Cavae (superior vena cava & inferior vena cava)
The _________ contains the two largest veins in the body, returning blood into the heart
Venae cavae
What is the term that describes the fluid pressure that blood exerts against vessel walls?
Blood pressure
Blood pressure is highest in _______ and lowest in ______. (hint: arteries/veins for both)
Blood pressure is highest in ARTERIES and lowest in VEINS.
Blood pressure is highest in the aorta and large arteries. It drops as blood enters __________ and falls drastically as blood moves through the _________.
Blood pressure is highest in the aorta and large arteries. It drops as blood enters SMALLER ARTERIES and falls drastically as blood moves through the SYSTEMIC ARTERIOLES.
__________, the link between arteries and veins, are the sites where molecules are exchanged between blood and interstitial fluid.
Capillaries
_________ is the volume of blood that the left ventricle pumps into the systemic circuit per minute.
Cardiac output (CO)
________ blood pressure is the minimum pressure in the arteries that is produced during the diastolic phase of the heart cycle.
Diastolic
During atrial and ventricular diastole, the atria and ventricles are ________. The AV valves ________, and the semilunar valves _______. Blood enters the __________ through the ________, and enters the ________ through the _____________.
During atrial and ventricular diastole, the atria and ventricles are RELAXED. The AV valves OPEN, and the semilunar valves CLOSE. Blood enters the RIGHT ATRIUM through the VENA CAVAE, and enters the LEFT ATRIUM through the PULMONARY VEINS.
During atrial systole, the atria _______ while the ventricles are _______. The AV valves are ______, while the semi lunar valves are _______. Blood enters the ventricles through the _________.
During atrial systole, the atria CONTRACT while the ventricles are RELAXED. The AV valves are OPEN, while the semi lunar valves are CLOSED. Blood enters the ventricles through the AV VALVES.
During systole, the heart pumps blood _______ through the _______; during diastole, the heart _______.
During systole, the heart pumps blood OUT through the ARTERIES; during diastole, the heart FILLS WITH BLOOD.
During ventricular systole, the atria ______ while the ventricles _______. The AV valves _____, while the semilunar valves ______. Blood moves from the __________ into the ___________ through the ________. Blood moves from the ________ into the ________ through the _________.
During ventricular systole, the atria RELAX while the ventricles CONTRACT. The AV valves CLOSE, while the semilunar valves OPEN. Blood moves from the RIGHT VENTRICLE into the PULMONARY TRUNK through the PULMONARY SEMILUNAR VALVE. Blood moves from the LEFT VENTRICLE into the AORTA through the AORTIC SEMILUNAR VALVE.
Blood pressure is about 40 mm Hg in the _________. a. arterial end of capillaries b. arteries c. venule end of capillaries d. veins
a. arterial end of capillaries
Which of these vessels receives blood during ventricular systole? a. both the aorta and pulmonary trunk b. aorta only c. pulmonary veins only d. pulmonary arteries only
a. both the aorta and pulmonary trunk
An electrocardiogram is a graphic illustration of the: a. cardiac conduction system b. cardiac cycle c. cardiac output d. systemic and pulmonary circuits e. coronary vessels
a. cardiac conduction system
What is the most characteristic function of capillaries? a. exchange of substances b. distributing blood to tissues c. blood transport away from the heart d. blood transport towards the heart
a. exchange of substances
In which of the following blood vessels would you expect to find a systolic blood pressure? a. pulmonary artery b. pulmonary vein c. arteriole in arm d. capillary in the leg e. superior vena cava
a. pulmonary artery
In the pulmonary circuit, the __________ half of the heart pumps __________ blood to the alveoli of the lungs, and then _____________ blood flows back to the heart. a. right; deoxygenated; oxygenated b. right; oxygenated; deoxygenated c. left; deoxygenated; oxygenated d. left; oxygenated; deoxygenated
a. right; deoxygenated; oxygenated
At the arteriole end of a capillary, O2 is being delivered to the interstitial fluid/tissue cells, as are essential nutrients like amino acids and glucose. At the venule end of the same capillary, CO2 is being picked up from the interstitial fluid/tissue cells, as is ammonia. This capillary bed is probably part of: a. the systemic circuit b. the pulmonary circuit c. either the systemic or the pulmonary circuit d. the alveolar wall
a. the systemic circuit
The tricuspid valve is closed ________. a. when the ventricle is in systole b. while the ventricle is in diastole c. by the movement of blood from atrium to ventricle d. while the atrium is contracting
a. when the ventricle is in systole
The chambers of the heart _________ contract and relax in a rhythmic cycle.
alternately
The ________ exits from the left ventricle and divides into branches that supply oxygenated blood to all body parts.
aorta
The three types of blood vessels are...
arteries, veins, and capillaries.
Pulse pressure is lost by the time blood reaches the _______.
arterioles
The automatic nature of the heartbeat is referred to as __________.
automaticity
Blood pressure is 0 in the ________. a. Large arteries b. Large veins c. Venule end of capillaries d. Arteriole end of capillaries
b. Large veins
The P wave of the ECG represents: a. ventricular depolarization b. atrial depolarization c. ventricular repolarization d. SA node excitation e. atrial systole
b. atrial depolarization
What is the most characteristic function of arterioles? a. exchange of substances b. distributing blood to tissues c. blood transport away from the heart d. blood transport towards the heart
b. distributing blood to tissues
Once action potentials are generated by the heart's intrinsic conduction system, they are conducted from myocardial cell to myocardial cell via ___________________ located in the _____________. a. desmosomes; intercalated discs b. gap junctions; intercalated discs c. actin and myosin; sarcomeres d. myofibrils; desmosomes e. T-tubules; sarcolemma
b. gap junctions; intercalated discs
Which of the following are involved directly in pulmonary circulation? a. superior vena cava, right atrium, and left ventricle b. right ventricle, pulmonary artery, and left atrium c. right atrium, aorta, and left ventricle d. left ventricle, aorta, and inferior vena cava
b. right ventricle, pulmonary artery, and left atrium
The structure of a capillary wall differs from that of a vein or artery because: a. capillaries have two tunics, while veins have three b. capillaries have more smooth muscle c. capillaries have only a tunica intima d. capillaries have one-way valves
c. capillaries have only a tunica intima
A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________. a. left upper arm b. left side of the head and neck c. right side of the head and neck and right upper arm d. myocardium of the heart
c. right side of the head and neck and right upper arm
Which two great vessels bring deoxygenated blood back to the heart? a. the aorta and the pulmonary trunk b. the pulmonary arteries and the pulmonary veins c. the superior and inferior venae cavae d. the aorta and the superior vena cava e. the coronary arteries and the coronary veins
c. the superior and inferior venae cavae
Blood pressure is about 20 mm Hg in the ________. a. arteriole end of capillaries b. arteries c. venule end of capillaries d. veins
c. venule end of capillaries
The AV valves are supported by strong collagen cords called __________.
chordae tendinae ("heart strings")
The ___________ initiates and coordinates the muscular activity of the heart.
conduction system
The steepest drop in blood pressure occurs in the ___________. a. Arteries b. Venules c. Veins d. Arterioles
d. Arterioles
Which statement best describes arteries? a. All contain valves to prevent the backflow of blood. b. Only large arteries are lined with endothelium. c. All carry oxygenated blood to the heart. d. All carry blood away from the heart.
d. carry blood away from the heart
Normal heart sounds are caused by which of the following events? a. opening and closing of the heart valves b. excitation of the SA node c. friction of blood against the chamber walls d. closure of the heart valves
d. closure of the heart valves
In the systemic circuit, the _____________ half of the heart pumps __________ blood to all body tissues, and then _________ blood flows back to the heart. a. right; deoxygenated; oxygenated b. right; oxygenated; deoxygenated c. left; deoxygenated; oxygenated d. left; oxygenated; deoxygenated
d. left; oxygenated; deoxygenated
The bicuspid or mitral valve is located between which two chambers of the heart? a. the right and left atria b. the right and left ventricles c. the right atrium and the left ventricle d. the left atrium and the left ventricle e. the right atrium and the pulmonary trunk
d. the left atrium and the left ventricle
Which two heart chambers pump oxygenated blood? a. the right and left atria b. the right and left ventricles c. the right atrium and the left ventricle d. the left atrium and the left ventricle e. the right atrium and the pulmonary trunk
d. the left atrium and the left ventricle
Which of these statements about veins is inaccurate? a. They possess less elastic and smooth muscle tissue than arteries. b. They possess more fibrous connective tissue than arteries. c. Most have one-way valves. d. They always carry deoxygenated blood. e. They are constructed of three tunics.
d. they always carry deoxygenated blood
The predominant driving force that moves blood back to the heart in the veins is: a. active transport b. passive transport c. the closing of one-way valves d. the beating of the heart e. the skeletal muscle contractions
e. skeletal muscle contractions
Arterioles are not as ________ as arteries, thus pulse pressure is smoothed out here.
elastic
Each valve in the heart consists of...
flaps or cusps of connective tissue.
It is the ______ that provides the motive force to move blood through the circulatory system so that metabolic fuels and waste products can be transported to and from the body tissues.
heart
Beats per minute represents _______.
heart rate (HR)
In arteries, blood pressure is _______.
high
Diastolic blood pressure is 80 mm Hg in the __________.
large arteries
Systolic blood pressure is 120 mm Hg in the _________.
large arteries
The veins, blood pressure is _______.
low
The monosyllables describing heart sounds during the cardiac cycle are ________.
lub-dub
Blood pressure is expressed in _______.
mm Hg
Because of _________, pressure is highest in the aorta and large arteries.
peripheral resistance
Because of _________, the pulse is smoothed out as blood moves away from the heart through the arterial system.
peripheral resistance
The respiratory pump sucks blood upward toward the heart as a result of....
pressure changes induced in the thoracic cavity by breathing.
In the ________ circuit, blood takes up oxygen in the lungs.
pulmonary
During relaxation of the left atrium, blood enters this chamber through the __________.
pulmonary veins
The ___________ enter the left atrium to bring oxygenated blood from the lungs to the heart.
pulmonary veins (btw, there are 4)
Blood pressure has a _____, or both a systolic and diastolic reading.
pulse
The activity of the conduction system, muscles, and valves of the heart are synchronized so that the heart can operate as a ______.
pump
The ________ forms most of the anterior surface of the heart.
right ventricle
In the ________ circuit, oxygenated blood is distributed to body tissues.
systemic
In the ________ circulation, blood in the capillaries delivers oxygen from the respiratory system and nutrients from the digestive system to all body cells.
systemic
The period of contraction in the heart is called ________.
systole
The surge of blood caused by the left ventricular contraction is called...
systole
At the arteriole end of a capillary, the blood pressure is just sufficient enough to ensure that blood will travel...
the length of the capillaries. (40 mm Hg)
The __________ is particularly large and important during youth; helps to program T cells of the immune system.
thymus
Most of the great vessels emerge ________ from the base of the heart. (pulmonary trunk, aorta, and superior vena cava)
upward
Heart murmurs (abnormal heart sounds) usually indicate ___________ problems.
valve
Pressure differentials that result from muscle activity actuate the opening & closing of ________.
valves
The heart is equipped with _______, which direct the flow of blood and prevent its backward movement.
valves
65% of the body's total blood volume is found in the _______ at any time.
veins
What follows directly after systole?
ventricular relaxation
Capillaries have such a small lumen that RBCs must squeeze through in a single file. Because of this, blood pressure drops as the blood reaches the ________.
venules
A heartbeat corresponds to one cardiac cycle, which lasts ~_____ second.
~0.8 second
_______ open and close to regulate the flow of blood through capillary beds.
Sphincters
The amount of blood pumped by the left ventricle each time it contracts is the _______.
Stroke volume (SV)