CARDIO VASCULAR SYSTEM Flashcards
delivers oxygen and nutrients to the body tissues and carries away wastes such as carbon dioxide via blood.
The cardiovascular system
directed toward the left hip and rests on the diaphragm, approximately at the level of the fifth intercostal space
apex
Its broad posterosuperior aspect, from which the great vessels of the body emerge, points toward the right shoulder and lies beneath the second rib.
base
The heart is enclosed by a sac called the
pericardium
The loosely fitting superficial part of pericardium, helps protect the heart and anchors it to surrounding structures, such as the diaphragm and sternum
fibrous pericardium
Deep to the fibrous pericardium is the slippery, two-layered
serous pericardium
The parietal layer of the serous pericardium, outside layer that lines the inner surface of the fibrous pericardium. a U-turn and continues inferiorly over the heart surface
parietal pericardium
The visceral layer of the serous pericardium, is the part of the heart also called the epicardium
visceral pericardium
is the innermost layer of the pericardium and the outermost layer of the heart wall
epicardium
Lubricating serous fluid is produced by the serous pericardial membranes and collects
between these serous layers.
This fluid allows the heart to beat easily in a relatively frictionless environment as the serous pericardial layers slide smoothly across each other.
serous fluid
Inflammation of the pericardium, often results in a decrease in the already small amount of serous fluid.
pericarditis
The heart walls are composed of three layers:
- the outer epicardium (the visceral pericardium just described)
- the myocardium
- and the innermost endocardium
consists of thick bundles of cardiac muscle twisted and whorled into ringlike arrangements, It is the layer that actually contracts
myocardium
are linked together by intercalated discs, which contain both desmosomes and gap junctions.
Myocardial cells
is a thin, glistening sheet of endothelium that lines the heart chambers. It is continuous with the linings of the blood vessels leaving and entering the heart.
endocardium
The heart has four hollow cavities, or chambers
two atria and two ventricles
are primarily receiving chambers
The superior atria
The superior atria are
primarily
receiving chambers
they are not important in the pumping activity of the heart. Instead, they assist with filling the ventricles.
superior atria
The inferior, thick-walled ventricles, or actual pumps of the heart
discharging chambers
forms most of the heart’s anterior surface
right ventricle
forms its apex
left ventricle
septum that divides the heart longitudinally where it divides the atria and the interventricular septum is referred to as the
interatrial septum
where it divides the ventricles
interventricular septum
side of the heart that works as the pulmonary circuit pump, receives oxygen-poor blood from the veins of the body through the large superior vena cava and inferior vena cava
right side
right side receives oxygen-poor blood and pumps it out through the
pulmonary trunk
The pulmonary trunk splits into 2, which carry blood to the lungs
right and left pulmonary arteries
Oxygen-rich blood drains from the lungs and is returned to the which side of the heart through the four pulmonary veins.
left side
Oxygen-rich blood drains from the lungs and is returned to the left side of the heart through
four pulmonary veins.
This circuit, from the right ventricle (the pump) to the lungs and back to the left atrium (receiving chamber), is called
pulmonary circulation
Its only function is to carry blood to the lungs for gas exchange and then return it to the heart.
pulmonary circulation
Oxygen-rich blood returned to the left atrium flows into the left ventricle and is pumped out to?
aorta
Oxygen-rich blood returned to the which atrium
left atrium
from ___, which the systemic arteries branch to supply essentially all body tissues.
aorta
After oxygen is delivered to tissues, oxygen-poor blood circulates from the tissues back to the right atrium via the
systemic veins
carry blood toward the heart
veins
carry blood away from the heart
arteries
This second circuit, from the left ventricle through the body tissues and back to the right atrium, It supplies oxygen- and nutrient-rich blood to all body organs, is called
systemic circulation
its walls are substantially thicker than those of the right ventricle and it is a much more powerful pump.
left ventricle
are located between the atria and ventricles on each side. These valves prevent backflow into the atria when the ventricles contract.
atrioventricular (AV) valves
The left AV valve, also called the mitral valve—consists of two flaps, or cusps, of endocardium.
bicuspid valve
The right AV valve, has
three cusps
the tricuspid valve
Tiny white cords, “tendinous
cords” anchor the cusps to the walls of the ventricles.
think of them as “heart strings”
chordae tendineae
The second set of valves, guards the bases of the two large arteries leaving the ventricular chambers.
semilunar valves
two large arteries leaving the ventricular chambers.
pulmonary semilunar valve and aortic semilunar valve
forces the heart to pump and repump the same blood because the valve does not close properly, so blood backflows.
incompetent valve
the valve cusps become stiff, often because of repeated bacterial infection of the endocardium (endocarditis).
valvular stenosis
branch from the base of the aorta and encircle the heart in the coronary sulcus (atrioventricular groove) at the junction of the atria and ventricles
coronary arteries
The functional blood supply that oxygenates and nourishes the myocardium is provided by
the right and left coronary arteries.
The coronary arteries branch from the base of the aorta and encircle the heart in the
coronary sulcus (atrioventricular groove)
The coronary arteries and their major branches
- the anterior interventricular artery circumflex artery on the left
- the posterior interventricular artery and marginal artery `on the right
The myocardium is drained by several ____, which empty into an enlarged vessel on the posterior of the heart called the coronary sinus.
cardiac veins
empties into the right atrium, posterior of the heart
coronary sinus.
the myocardium is deprived of oxygen often result in crushing chest pain
angina pectoris
the oxygen-deprived heart cells may die, forming an area called an
infarct
or MI, is commonly called a “heart attack” or a “coronary.”
myocardial infarction
which act like brakes and gas pedals to decrease or increase the heart rate, depending on which division is activated.
autonomic nervous system
that is built into the heart tissue and sets its basic rhythm like a drummer sets the beat for a rock band playing a song.
intrinsic conduction system, or nodal system
This system causes heart muscle depolarization in only one direction—from the atria to the ventricles.
intrinsic conduction system, or nodal system
located in the right atrium, one of the most important parts of the intrinsic conduction system is a crescent-shaped node of tissue called
sinoatrial (SA) node
which spread within the myocardium of the ventricle walls.
Purkinje fibers
at the junction of the atria and ventricles
atrioventricular (AV) node
the atrioventricular (AV) bundle (bundle of His) and the right and left bundle branches located in the
interventricular septum
any damage to the AV nod can partially or totally block the ventricles from the control of the SA node. the ventricles begin to beat at their own rate, which is much slower, some or all of the time.
heart block
or lack of an adequate blood supply to the heart muscle, may lead to fibrillation
Ischemia
a rapid, uncoordinated quivering of the ventricles, makes the heart unable to pump any blood and so is a major cause of death from heart attacks in adults.
fibrillation
is a rapid heart rate (over 100 beats per minute).
Tachycardia
is a heart rate that is substantially slower than normal (less than 60 beats per minute).
Bradycardia
refers to the events of one complete heartbeat, during which both atria and ventricles contract and then relax.
cardiac cycle
period of contraction of the ventricles of the heart that occurs between the first and second heart sounds of the cardiac cycle
Systole
the relaxation of the heart during which its cavities expand and fill with blood
diastole
We will consider the cardiac cycle in terms of events occurring during five periods
- Atrial diastole (ventricular filling)
- Atrial systole
- Isovolumetric contraction
- Ventricular systole (ejection phase)
- Isovolumetric relaxation
cardiac cycle period where heart completely relaxed, Pressure in the heart is low, the AV valves are open, and blood is flowing passively through the atria into the ventricles. The semilunar valves are closed.
- Atrial diastole (ventricular filling).
cardiac cycle period where the ventricles continue to contract, causing the intraventricular pressure to surpass the pressure in the major arteries leaving the heart. This causes the semilunar valves to open and blood to be ejected from the ventricles. During this phase, the atria are again relaxed and filling with blood.
- Ventricular systole (ejection phase)
cardiac cycle period where the ventricles remain in diastole as the atria contract, forcing blood into the ventricles to complete ventricular filling.
- Atrial systole.
cardiac cycle period where atrial systole ends, and ventricular systole begins. The initial rise in intraventricular pressure closes the AV valves, preventing backflow of blood into the atria. For a moment, the ventricles are completely closed chambers.
- Isovolumetric contraction
cardiac cycle period where as ventricular diastole begins, the pressure in the ventricles falls below that in the major arteries, and the semilunar valves close to prevent backflow into the ventricles.
- Isovolumetric relaxation.
heart sounds are often described by the two
syllables
“lub” and “dup”
The first heart sound is caused by the closing of the AV valves. -longer and louder
“lub”
The second heart sound occurs when the semilunar valves close at the end of ventricular systole. - short and sharp
“dub”
Abnormal or unusual heart sounds are called
heart murmurs
if a valve does not close tightly, a swishing sound will be heard after that valve has (supposedly) closed
valved is incompetent
traces the flow of current through the heart
electrocardiograph (ECG)
The first wave, which follows the firing of the SA node, is the __. small and signals the depolarization of the atria immediately before they contract.
Pwave.
which results from the depolarization of the ventricles, has a complicated shape. It precedes the contraction of the ventricles.
QRS complex
results from currents flowing during the repolarization of the ventricles.
T wave
is the amount of blood pumped out by each side of the heart
Cardiac output (CO)
Cardiac output (CO) is the product of
heart rate (HR) and the stroke volume (SV)
is the volume of blood pumped out by a ventricle with each heartbeat.
stroke volume (SV)
The important factor stretching the heart muscle, the amount of blood entering the heart and distending its ventricles.
venous return
the enhanced squeezing action of active skeletal muscles on the veins helps return blood to the heart, plays a major role in increasing the venous return
muscular pump
the autonomic nervous system more strongly stimulate the SA and AV nodes and the cardiac muscle itself. As a result, the heart beats more rapidly.
sympathetic division
primarily vagus nerve fibers, slow and steady the heart, giving it more time to rest during noncrisis times
Parasympathetic nerves
which mimics sympathetic nerves and is released in response to sympathetic nerve stimulation
epinephrine
a thyroid hormone, increase heart rate.
thyroxine
The average adult heart rate is
faster in females
72–80 beats per minute
progressive condition that reflects weakening of the heart by coronary atherosclerosis
congestive heart failure (CHF)
The average adult heart rate is
faster in males
64–72 beats per minute
If the left heart fails, The right side of the heart continues to propel blood to the lungs, but the left side is unable to eject the returning blood into the systemic circulation.
pulmonary congestion
If the right side of the heart fails, as blood backs up in the systemic circulation.
peripheral congestion
Blood circulates inside the blood vessels, which
form a closed transport system
vascular system
As the heart beats, it propels blood into the large, leaving the heart
arteries
Capillary beds are drained by__, which in turn empty into veins that merge and finally empty into the great veins (venae cavae) entering the heart
venules
which lines the lumen, or interior, of the vessels, is a thin layer of endothelium (squamous epithelial cells) resting on a basement membrane
tunica intima
is the bulky middle layer, made up mostly of smooth muscle and elastic fibers. Controlled by sympathetic nervous system.
tunica media
Some of the larger arteries have, sheets of elastic tissue, in addition to the scattered elastic fibers.
elastic laminae
which is controlled by the sympathetic nervous system, is active in changing the diameter of the vessels.
smooth muscle
that prevent backflow of blood like those
in the heart in the larger vein
valves
The flow of blood from an arteriole to a venule—that is, through a capillary bed—is called
microcirculation
a vessel that directly connects the arteriole and venule at opposite ends of the bed
vascular shunt
the actual exchange vessels, Entrances to capillary beds are guarded by precapillary sphincters,
true capillaries
Mostly fibrous connective tissue, Supports and protects the vessel
unica externa forms protective outermost covering
Largest artery in the body
Leaves from the left ventricle of the heart
Aorta
leaves the left ventricle
ascending aorta
true capillaries spring from the terminal arteriole and empty directly into the
postcapillary venule
true capillaries spring from __ and empty directly into the postcapillary venule
terminal arteriole
A cuff of smooth muscle fibers, surrounds the root of each true capillary and acts as a valve to regulate the flow of blood into the capillary.
precapillary sphincter
Blood flowing through a terminal arteriole may take one of two routes:
through the true capillaries or through the shunt
blood flows through the true capillaries and takes part in exchanges with tissue cells, the precapillary sphincters are
relaxed (open)
blood flows through the shunts and bypasses the tissue cells in that region, the precapillary sphincters are
contracted (closed)
are common in people who stand
for long periods of time, and in obese (or pregnant) individuals.
Varicose veins
A serious complication of varicose veins, inflammation of a vein that results when a clot forms in a vessel with poor circulation.
thrombophlebitis
which is a life-threatening condition in which the embolism lodges in a vessel in the lung.
pulmonary embolism
The aorta springs upward from the left ventricle of the heart as the
(leaves the left ventricle)
ascending aorta
arches to the left as the
aortic arch
travels downward through the thorax
Thoracic aorta
passes through the diaphragm into the abdominopelvic cavity
Abdominal aorta
The only 2 branches of the ascending aorta, which serve the heart
right (R.) coronary artery and left (L.) coronary artery
the first branch off the aortic arch
brachiocephalic trunk
which further branches into the R. internal and R. external carotid arteries
R. common carotid artery
vessels on the left side ofthe body for organs served.
R. subclavian artery
Left common carotid artery- second brand off the aortic arch.
splits into the:
Left internal and external carotid arteries
Left subclavian artery branches into the:
Vertebral artery
L. common carotid artery which serves the brain
L. internal carotid
L. common carotid artery which serves the
skin and muscles of the head and neck.
L. external carotid
The third branch of the aortic arch, that gives off an important branch vertebral artery
L. subclavian artery
L. subclavian artery which serves part of the brain.
vertebral artery
In the axilla, the subclavian artery becomes the
axillary artery
the subclavian artery continues into the arm, which supplies the arm
brachial artery
At the elbow, the brachial artery splits to form the, which serve the forearm.
radial artery and ulnar artery
(10 pairs) supply the muscles of the thorax wall.
intercostal arteries
Other branches of the thoracic aorta supply the lungs
bronchial arteries
Other branches of the thoracic aorta supply the esophagus
esophageal arteries
Other branches of the thoracic aorta supply the diaphragm
phrenic arteries
is the first branch of the abdominal aorta, single vessel that has three branches
celiac trunk
branch of celiac trunk supplies the stomach
the L. gastric artery
branch of celiac trunk supplies the spleen
splenic artery
branch of celiac trunk supplies liver
common hepatic artery
unpaired, supplies most of the small intestine and the first half of the large intestine, or colon
superior mesenteric artery
serve the kidneys.
Renal (R. and L.) arteries
Gonadal arteries in the female, serving ovaries
ovarian arteries
Gonadal arteries in the male, serving testes
testicular arteries
are several pairs of arteries serving the heavy muscles of the abdomen and trunk walls.
lumbar arteries
is a small, unpaired artery supplying the second half of the large intestine.
inferior mesenteric artery
are the final branches of the abdominal aorta.
common iliac arteries
common iliac arteries which supplies the pelvic organs
internal iliac artery
common iliac arteries which enters the thigh, where it becomes the
femoral artery
The femoral artery and its branch, serve the thigh
deep artery of the thigh
At the knee, the femoral artery becomes the
popliteal artery
The femoral artery and its branch, which supply the leg and foot
anterior tibial artery and posterior tibial artery
supplies the dorsum of the foot.
arcuate artery
Veins draining the head and arms empty into
superior vena cava
deep veins draining the forearm
radial vein and ulnar vein
Veins draining the lower body empty into
inferior vena cava
radial vein and ulnar vein unite to form the deep
brachial vein
drains the arm and empties
axillary vein
provides for the superficial drainage of the lateral aspect of the arm and empties into the axillary vein
cephalic vein
is a superficial vein that drains the medial aspect of the arm and empties into the brachial vein proximally.
basilic vein
The basilic and cephalic veins are joined at the anterior aspect of the elbow by the
median cubital vein
is often chosen as the site for withdrawing blood for the purpose of blood testing
median cubital vein
receives venous blood from the arm through the axillary vein
subclavian vein
receives venous blood from the skin and muscles of the head through the
external jugular vein
drains the posterior part of the head.
vertebral vein
drains the dural sinuses of the brain.
internal jugular vein
are large veins that receive venous drainage from the subclavian, vertebral, and internal jugular veins on their respective sides.
brachiocephalic (R. and L.) veins
single vein that drains the thorax and enters the superior vena cava just before it joins the heart.
azygos vein
which is much longer than the superior vena cava, returns blood to the heart from all body regions inferior to the diaphragm
inferior vena cava
drain the leg, calf and foot
anterior tibial vein and posterior tibial vein and the fibular vein
are the longest veins in the body. They receive the superficial drainage of the leg.
great saphenous vein
is formed by the union of the external iliac vein and the internal iliac vein
common iliac vein (L. and R.)
drains the right ovary in females and the right testicle in males.
R. gonadal vein
drains the left ovary in females and the left testicle in males.
L.gonadal vein
drain the kidneys.
renal veins
single vein that drains the digestive tract organs and carries this blood through the liver before it enters the systemic circulation.
hepatic portal vein
drain the liver
hepatic (R. and L.) veins
branches of the common carotid arteries, run through the neck and enter the skull through the temporal bone
internal carotid arteries
pass upward from the subclavian arteries at the base of the neck.
vertebral arteries
Within the skull, the vertebral arteries join
to form the single
basilar artery.
supply the posterior part of the cerebrum, At the base of the cerebrum, the basilar artery divides to form
posterior cerebral arteries
The anterior and posterior blood supplies of the brain are united by small
communicating arterial branches
The result is a complete circle of connecting blood vessels, which surrounds the base of the brain called
cerebral arterial circle or the circle of Willis
protects the brain by providing more than one route for blood to reach brain tissue in case ofa clot or impaired blood flow anywhere in the system.
The cerebral arterial circle
veins that drain the digestive organs, spleen, and pancreas and deliver this blood to the liver through the hepatic portal vein
hepatic portal circulation
draining the terminal part of the large intestine, drains into the splenic vein
inferior mesenteric vein
which drains the right side of the stomach, drains directly into the hepatic portal vein.
L. gastric vein
These measurements, along with those of respiratory rate and body temperature, are referred to collectively as
vital signs
The alternating expansion and recoil of an artery that occurs with each beat of the left ventricle creates a pressure wave that travels
through the entire arterial system
pulse
is the pressure the blood exerts against the inner walls of the blood vessels, and it is the force that keeps blood circulating continuously even between heartbeats
blood pressure
Recall that the blood flows into the smaller arteries, then arterioles, capillaries, venules, veins, and finally back to the large venae cavae entering the right atrium of the heart
TRUE
the pressure in the arteries at the peak of ventricular contraction
systolic pressure
the pressure when the ventricles are relaxing
diastolic pressure
procedure is used to measure blood pressure in the brachial artery of the arm, systemic arterial blood pressure is measured indirectly by the
auscultatory method
is the amount of friction the blood encounters as it flows through the blood vessels.
Peripheral resistance
The major action of the sympathetic nerves on the vascular system is to cause narrowing of the blood vessels, which increases the blood pressure
vasoconstriction
this activated when we stand up suddenly after lying down, gravity causes blood to pool very briefly in the vessels of the legs and feet,and blood pressure drops.
pressoreceptors, also called baroreceptors
a chemical that increase both hearts rate and blood pressure
epinephrine
or low blood pressure, is generally considered to be a systolic blood pressure below 100 mm Hg or low blood pressure, is generally considered to be a systolic blood pressure below 100 mm Hg
hypotension
Elderly people may experience temporary low blood pressure and dizziness when they rise suddenly from a reclining or sitting position
orthostatic hypotension
may hint at poor nutrition and inadequate levels of blood proteins, blood viscosity is low, blood pressure is also lower than normal.
Chronic hypotension
high blood pressure, is pathological and is defined as a condition of sustained elevated arterial pressure of140/90 or higher.
hypertension (high blood pressure)
he kidneys release water in the urine If blood pressure is
too high
Kidneys regulate blood pressure by
alternating blood volume
he kidneys release renin to trigger formation of angiotensin II, a vasoconstrictor, if the blood pressure is
too low
stimulates release of aldosterone, which enhances sodium (and water) reabsorption by kidneys
Angiotensin II
Systolic pressure ranges from
110 to 140 mm Hg
Diastolic pressure ranges from
70 to 80 mm Hg
Substances take various routes entering or leaving the blood
- Direct diffusion through membranes
- Diffusion through intercellular clefts (gaps between cells in the capillary wall)
- Diffusion through pores of fenestrated capillaries
- Transport via vesicles
Fluid movement forces fluid and solutes out of capillaries
blood pressure
Fluid movement draws fluid into capillaries
Osmotic pressure
osmotic pressure at the arterial end of the capillary bed, Blood pressure is
higher
osmotic pressure at the venous end of the capillary bed, blood pressure is
lower
Carries nutrients and oxygen from maternal blood to fetal blood
umbilical cord
which carries nutrient- and oxygen-rich blood to the fetus
one umbilical vein
which carry wastes and carbon dioxide–rich blood from the fetus to placenta
two umbilical arteries
connects aorta and pulmonary trunk (becomes ligamentum arteriosum at birth)
ductus arteriosus
Age-related problems associated with the cardiovascular system include:
- Weakening of venous valves
- Varicose veins
- Progressive arteriosclerosis
- Hypertension resulting from loss of elasticity of vessels
- Coronary artery disease resulting from fatty, calcified deposits in the vessels
