Cardiovascular System - Anatomy and Physiology - Laboratory Flashcards
delivers oxygen, nutrients, hormones, and other vital substances to the tissues of the body and then transports waste materials from the body cells to their elimination sites.
the cardiovascular system—the blood, heart, and blood vessels
a fist-sized, four-chambered muscular pump lying within the mediastinum of the thoracic cavity
heart
surrounded by a double-layered membrane called the pericardium
heart
a double-layered membrane that surrounds the heart
pericardium
Blood vessels enter and leave the heart at its broad __________
base
the inferior tip of the heart is called the
apex
The pericardium consists of an outer, dense irregular connective tissue layer called
fibrous pericardium
anchors the heart to surrounding structures
fibrous pericardium
The pericardium consists of an outer, dense irregular connective tissue layer—the fibrous pericardium— that anchors the heart to surrounding structures, and an
inner _____________________________
serous pericardium
the inner serous pericardium is composed of two layers separated by a narrow serous fluid-filled cavity called the
pericardial cavity
reduces friction during muscular contraction.
pericardial fluid
the outer layer of the serous pericardium
parietal pericardium
is fused to the fibrous pericardium
parietal pericardium
the inner layer of the serous pericardium
visceral pericardium
is attached to the heart muscle and forms the epicardium
visceral pericardium
the outer layer of the heart wall
epicardium
The heart wall also contains a middle muscular layer called the
myocardium
The heart wall also contains a middle muscular layer called the myocardium and an inner layer called the
endocardium
is composed of a specialized simple squamous epithelium that rests on a thin layer of areolar connective tissue, and it is continuous with the innermost lining of blood vessels throughout the body
endocardium
Two superior thin-walled chambers
atria
receive and direct blood coming into the heart
atria
on the outer surface of each atrium is a flap-like structure called an
auricle
receives deoxygenated blood from the superior and inferior venae cavae of the systemic circuit and the coronary sinus of the coronary circulation
right atrium
receives oxygenated blood from the four pulmonary veins of the pulmonary circuit.
left atrium
Lining the right atrium are comb-like muscular ridges called
pectinate muscles
provide additional strength to the atrial wall
pectinate muscles
The atria are separated by a thin wall called the
interatrial septum
A depression in the interatrial septum called the
fossa ovalis
is the remnant of the foramen ovale
fossa ovalis
an opening between the right and left atria by which the pulmonary circuit is bypassed in the fetus.
foramen ovale
Two inferior thick-walled chambers, called _______________,
pump blood.
ventricles
receives deoxygenated blood from the right atrium and pumps it into the pulmonary circuit via the pulmonary trunk, which branches into the left and right pulmonary arteries.
right ventricle
the right ventricle receives deoxygenated blood from the right atrium and pumps it into the pulmonary circuit via the
pulmonary trunk
a band of connective tissue at the point where the pulmonary trunk branches into the right artery and left pulmonary arteries
ligamentum arteriosum
is a remnant of the ductus arteriosus
ligamentum arteriosum
a fetal blood vessel that shunts blood from the pulmonary trunk to the aorta
ductus arteriosus
receives oxygenated blood from the left atrium and pumps it into the systemic circuit via the ascending aorta.
left ventricle
The left ventricle receives oxygenated blood from the left atrium and pumps it into the systemic circuit via the?
ascending aorta
Both ventricular walls are characterized by the presence of a distinct network of muscular ridges called
trabeculae carneae
Four valves within the heart ensure that blood continues flowing in one direction only:
- tricuspid valve (or right atrioventricular valve)
- mitral (bicuspid) valve (or left atrioventricular valve)
- pulmonary valve (or pulmonary semilunar valve)
- pulmonary valve (or pulmonary semilunar valve)
prevents backflow of blood from the right ventricle to the right atrium
tricuspid valve (or right atrioventricular valve)
prevents backflow of blood from the left ventricle to the left atrium
mitral (bicuspid) valve (or left atrioventricular valve)
open when the contracting ventricles pump blood into the arteries and then close to prevent blood from flowing back into the ventricles.
pulmonary valve (or pulmonary semilunar valve) and aortic valve (or aortic semilunar valve)
The tricuspid and mitral (bicuspid) valves are anchored to the _______________________ of the ventricular wall by structures called ________________________
papillary muscles; chordae tendineae
is the predominant tissue type of the heart
Cardiac muscle tissue
are short, branched, uninucleate cells filled with the contractile proteins action and myosin
Cardiac muscle fibers
The regular arrangement of the actin and myosin produces ______________ giving the cells a striped appearance.
striations
Individual cardiac muscle fibers are connected by structures called
intercalated discs
Intercalated discs contain both
desmosomes and gap junctions
anchoring junctions that prevent cardiac muscle fibers from
pulling apart during contraction
desmosomes
junctions that allow the movement of materials from one cell to the next
gap junctions
Deoxygenated blood ejected into the pulmonary trunk by the right ventricle enters the _____________________
pulmonary circuit
Oxygenated blood pumped by the left ventricle through the aorta enters the ______________________ and is distributed to all parts of the body before returning to the right atrium via one of the venae cavae.
systemic circuit
A branch of the systemic circuit—the _____________________—supplies the myocardium with the oxygen and
nutrients needed for muscle contraction.
coronary circulation
branches into the marginal artery and the posterior interventricular artery
right coronary artery
The right coronary artery branches into the
marginal artery and the posterior interventricular artery.
branches into the circumflex artery and the anterior interventricular artery
left coronary artery
the left coronary artery branches into the
circumflex artery and the anterior interventricular artery
The pulmonary circuit
- Deoxygenated blood is pumped to the lungs by the right side of the heart.
- Gas exchange occurs between alveoli and blood in the pulmonary capillaries.
- Oxygenated blood is returned to the left side of the heart.
The systemic circuit
- Oxygenated blood is pumped to the body by the left side of the heart
- Gas exchange occurs between tissues and blood in the systemic capillaries.
- Deoxygenated blood is returned to the right side of the heart.
The myocardium is drained by the
great, middle, and small cardiac veins
The myocardium is drained by the great, middle, and small
cardiac veins, all of which eventually empty into the ______________________, which drains into the right atrium.
coronary sinus
