anatomy

Arteries are strong, elastic vessels adapted for carrying high-pressure blood away from the heart. Arteries become smaller as they divide and become _________________.

arterioles

The blood vessels (arteries, arterioles, capillaries, venules, and veins) form a closed tubular system that carries blood ______ the heart, to the cells, and _______ again.

away from, back

Pathway of blood: right ventricle to the _________________ valve

pulmonary

Pathway of blood: pulmonary arteries to the ___________

pulmonary capillaries of lungs

Pathway of blood: pulmonary valve to the _______________ ________

pulmonary trunk

Pathway of blood: pulmonary capillaries of lungs to the ____________ _________, ________ __________, _______________ valve

pulmonary veins, left atrium, Bicuspid valve

Blood vessels can be divided into 2 major pathways, the ____________ circuit, which goes from the heart to the lungs and back, and the ____________ circuit, which goes from the heart to the body cells and back.

pulmonary, systemic

The surge of blood that occurs with ventricular contraction can be felt at certain points in the body as a ____________.

pulse

Pathway of blood: Superior and inferior vena cava to the

right atrium

Pathway of blood: tricuspid valve to the _______ __________

right ventricle

The heart has four internal chambers: two upper and two lower chambers. A _____________ divides the chambers on the left side from those on the right.

septum

Specialized cardiac muscle tissue conducts impulses throughout the myocardium and comprises the cardiac conduction system. A self-exciting mass of specialized cardiac muscle called the ________ node, located in the posterior right atrium, generates the impulses for heartbeats. Therefore, it is also called the _______ of the heart.

sinoatrial, pacemaker

Contractions of _____________muscles squeeze blood back up veins one valve at a time.

skeletal

The _______________ control center of the ______________ _______________ maintains a balance between the two autonomic divisions of the nervous system in response to messages from ___________________, which detect changes in blood pressure.

cardiac, medulla oblongata, baroreceptors

Impulses from _______________ or ________________ may also influence the cardiac control center. Body temperature and the concentrations of certain _________ also influence heart rate.

cerebrum_, hypothalamus, ions

The heart is a hollow, ________________-shaped, muscular pump within the ________________; it rests on the ____________.

cone shaped, the thoracic cavity, superior to the diaphragm

The first branches off of the aorta, which carry oxygen-rich blood, are the right and left __________ arteries that feed the heart muscle itself. Branches of these arteries feed many capillaries of the myocardium.

coronary

These tough rings prevent dilation of tissue in this area.

dense connective tissue

_______ leads to contraction of the chamber, and repolarization leads to relaxation

depolarization

The inner __________________ is smooth and made up of connective tissue and epithelium, and is continuous with the endothelium of major vessels joining the heart.

endocardium

Capillaries are the smallest blood vessels, consisting only of a layer of _________________, through which substances are exchanged with tissue cells.

endothelium

The outermost layer, the ______________, is made up of connective tissue and epithelium, and contains blood and lymphatic capillaries along with ____________ arteries that provide blood to the heart. It is the same as the ___________ pericardium.

epicardium, coronary, visceral

The tunica __________________ is the outermost layer of connective tissue.

externa

The pericardium consists of two layers: the outer, tough connective tissue _____________ pericardium, surrounding a more delicate double-layered sac that surrounds the heart.

fibrous

Areas with a great deal of metabolic activity (leg muscles, for example) have _______ densities of capillaries.

higher

When the atria fill, pressure in the atria is _______ than that of the ventricles, which forces the _______ and ______ valves open. Pressure inside atria rises further as they contract, forcing the remaining blood into the ventricles.

higher, tricuspid, mitral

When the ventricles contract, pressure inside them ____________ sharply, causing the _________ and _______ valves to close, and the _________ and ________ valves to open.

increases, tricuspid, mitral, pulmonary, aortic

The wall of an artery consists of an inner endothelial layer, called the tunica ___________.

interna

Blood pressure at the venular end of a capillary is almost _________. So other factors help return the blood to the heart.

0

The average adult heart is ________ cm long and ________ cm wide.

14 long and 9 wide

The heart lies posterior to the sternum; its apex extends to the ________ intercostal space.

5th

Pathway of blood: Bicuspid valve to the _______ _____________

left ventricle

Arterial blood pressure rises and falls, following a pattern established by the cardiac cycle. During ventricular contraction, arterial pressure is at its _______________ or ______________ pressure.

maximum, systolic

The impulse proceeds to the next conduction structure, the _______bundle (Bundle of _____), which splits into the left and right ___________ __________. These branches give rise to ______________ fibers, which lead into the ventricular myocardium and the papillary muscles.

AV, His, bundle branches, Purkinje

Pathway of blood: left ventricle to the ________________ valve, _

Aortic semilunar valve

The middle layer, called the tunica _______________ is made up of smooth muscle and elastic connective tissue.

media

Where are the semilunar valves found?

At the exits from the ventricle

Upper chambers, ___________, receive blood returning to the heart, and have thin walls and ear-like auricles projecting from their exterior. Below them, the thick-muscled _________________ pump blood to the body and lungs.

Atria, ventricles

When the ventricles are relaxing, arterial pressure is at its _________________ or ______________ pressure.

minimum, diastolic

What are the four factors that affect blood pressure?

Cardiac output, blood volume, peripheral resistance, blood flow, and viscosity of the blood

_________ veins drain blood from the heart muscle, and carry it to the coronary ________ , which drains into the right atrium.

Cardiac, sinus

Which part of the pathway is systemic?

From the left ventricle, to the body cells through the aorta, systemic arteries, capillaries and veins, and returning to the right atrium through the superior and inferior vena cava

Which part of the pathway is pulmonary?

From the right ventricle, through the pulmonary trunk, arteries, capillaries, and veins, and returning to the left atrium

The middle layer, called the ________________, consists of cardiac muscle and is the thickest layer of the heart wall.

myocardium

At the venular end of the capillary, ____________ pressure, due to the proteins in the blood, causes much of the tissue fluid to return to the bloodstream. ________________ capillaries collect excess tissue fluid and return it to the circulation.

Hydrostatic, osmotic, Lymphatic

___________ fibers are small, allowing the atria to contract before the impulse spreads rapidly over the ventricles.

Junctional

The first wave, the _____ wave, corresponds to the ___________________ of the atria.

P, depolarization

_________________ sphincters can regulate the amount of blood entering a capillary bed, and are controlled by the ___________ concentration in the area. If blood is needed elsewhere in the body, the capillary beds in less important areas are shut down.

Precapillary, oxygen

The __________ complex corresponds to the ________________ of the ventricles and hides the ________________ of the atria.

QRS, depolarization, repolarization

Pathway of blood: pulmonary trunk to the____________, ___________ ____________ , ___________, and through the arteries to provide blood to the body cells.

Right and left pulmonary arteries

What are the functions of the CV system?

Supplies oxygen, nutrients to the tissues; removes wastes

The _________ wave ends the ECG pattern and corresponds to ventricular __________________.

T, repolarization

The cardiovascular (CV) system consists of ________?

The heart, and blood vessels (arteries, capillaries and veins).

How do veins differ from arteries?

They are thinner, less muscular, and the blood is at much lower pressure in the veins

Why do plasma proteins remain in the blood? ________

They are too large to get through the capillary walls

What is the function of systemic circulation?

To distribute oxygen and nutrients to tissues throughout the body

What is the function of pulmonary circulation?

To oxygenate the blood and remove carbon dioxide

What is semilunar valves function?

To prevent backflow of blood into ventricles as the ventricles relax

Blood entering capillaries contains high concentrations of ____________ and ____________ that diffuse out of the capillary wall and into the ___________ __________.

oxygen, nutrients, tissue fluids

As the ventricles contract, _______ muscles contract, pulling on _______ and preventing the backflow of blood through the tricuspid and mitral valves.

papillary, chordae tendineae

At the base of the heart, the inner layer folds back to become the ______________ pericardium.

parietal

Between the visceral and parietal layers of the pericardium is a potential space called the __________ cavity; it is filled with ________ fluid, which reduces friction.

pericardial, serous

The heart muscle requires a continuous supply of oxygen-rich blood, so smaller branches of arteries often have ___________ as alternate pathways for blood, should one pathway become blocked.

anastomoses

Blood pressure is the force of blood against the inner walls of blood vessels anywhere in the cardiovascular system, although the term "blood pressure" usually refers to ____________ pressure.

arterial

The amount of blood pumped at any time must adjust to the current needs of the body (more is needed during strenuous exercise). The SA node is innervated by branches of the ________________ and __________________ divisions of the nervous system, so the CNS helps to control heart rate. Impulses from the former speed up, and impulses from the latter slow down heart rate.

sympathetic, parasympathetic

A mass of merging fibers that act as a unit is called a functional ________; one exists in the atria and one in the ventricles.

syncytium

The cardiac cycle consists of the atria beating in unison, called atrial _____, while the ventricles rest, called ventricular _______. This is followed by the contraction of both ventricles, called ventricular _______, while the atria relax, called atrial ______. Then the entire heart relaxes for a brief moment.

systole, diastole, systole, diastole

Pathway of blood: aortic semilunar valve to the __________

the arteries to provide blood to the body cells.

Differences in __________ and ___________________ pressures, derived from the breathing process, draw blood back up the veins.

thoracic, abdominal

The wall of the heart is composed of ______ distinct layers.

three

Pathway of blood: right atrium to the _______________ valve

tricuspid

The right atrioventricular (AV) valve, called the ________________ valve, and the left AV valve, called either the ______________ or the _________ valve, have cusps to which strings called ______________ ________________ attach. These strings are, in turn, attached to _____________ muscles in the inner heart wall, which contract during ventricular contraction to prevent the backflow of blood through the AV valves.

tricuspid, bicuspid, mitra, chordae tendineae, papillary

During the cardiac cycle, pressure within the heart chambers rises and falls. These pressure changes open and close ._____

valves

Veins have the same three layers as arteries, and have flap-like ___________ inside to prevent backflow of blood.

valves

Rings of dense connective tissue surround the pulmonary trunk and aorta to provide attachments for the heart _____________ and __________ __________.

valves and muscle fibers

Arteries are capable of __________________ as directed by sympathetic impulses; when impulses are inhibited, the diameter of the vessel increases, which is called ________

vasoconstriction, vasodilation

Heart sounds can be described as a "lubb-dupp" sound. The first sound (lubb) occurs as the_______ contract and the ________ and ____________ valves are closing. The second sound (dupp) occurs as relax and aortic and ________ valves are closing.

ventricles, tricuspid, and mitral, ventricles, pulmonary

Small vessels called _________________ lead away from capillaries, and merge to form larger _____________ that return blood to the heart.

venules, veins

The inner layer directly covers the heart and is called the _________ pericardium

visceral