Chapter 22: Heart Flashcards
Types of blood vessels in the heart
- Veins
- Arteries
Blood vessels that carry blood away from the heart
arteries
blood vessels that carry blood back to the heart
veins
the arteries and veins entering and leaving the heart are called:
great vessels
Blood flow through the heart is (unidirectional/bidirectional) because of four valves within the heart
Unidirectional
The heart generates _______ ______ through alternate cycles of the heart wall’s contraction and relaxation
Blood pressure
Define Blood Pressure
the force of blood pushing against the inside walls of blood vessels.
Two types of circulations within the cardiovascular system:
- Pulmonary
- Systemic
Describe Pulmonary Circulation
the right side of the heart and the pulmonary arteries and veins ciculates blood to the lungs and back to the left side of the heart.
Describe Systemic Circulation
the left side of the heart, arteries and veins circulate blood to most body tissues and back to the right side of the heart.
Describe where the heart is located in the body
slightly left of midline, deep to the sternum, in the mediastinum
The heart is enclosed within a tough sac called the ____________
pericardium
restricts heart movements so that it moves only slightly within the thorax
Pericardium
Two parts of the Pericardium
- Fibrous pericardium
- Serous pericardium
What is fibrous pericardium
outer layer covering of tough, dense CT
Two layers of serous pericardium:
- parietal layer
- visceral layer (epicardium)
Describe the parietal layer of serous pericardium
lines the inner surface of the fibrous pericardium
Describe the visceral layer (epicardium) of serous pericardium
covers the outer surface of the heart
The small space between the parietal and visceral layers is called the ________ _________.
pericardial cavity
Three layers of the heart wall (superficial to deep)
- Epicardium
- Myocardium
- Endocardium
Which heart wall layer consists of the visceral layer of the serous pericardium and areolar CT
Epicardium
Which heart wall layer is made up of cardiac muscle and is the thickest of the three layers
Myocardium
Which heart wall layer is the internal surface of the heart chambers and external surface of the heart valves
Endocardium
Cone-shaped muscle projections inside the ventricle called ______ _______
papillary muscles
papillary muscles anchor thin strands of strong CT made up of collagen fibers called ________ ________.
chordae tendineae
______ are triangular flaps that hang down into the ventricle.
Cusps
The ____ ventricular wall is usually three times thicker than the ____ventricular wall
left; right
Name the semilunar valves
Pulmonary and Aortic
Location of the fibrous skeleton of the heart
between the atria & ventricles
what is the composition of the fibrous skeleton of the heart
Dense, regular fibrous CT
What are the functions of the fibrous skeleton of the heart
- Anchor heart valves by forming a supportive ring at their attachment points
- Electrical insulation between atria and ventricles
- Rigid framework for attachment of cardiac muscle cells
These arteries travel within the coronary sulcus and supply the heart wall muscle with oxygen and nutrients
right and left coronary arteries
Name of the only branches given off by the ascending aorta just superior to the semilunar valve:
coronary arteries
Right coronary artery branches into:
- Marginal artery
- Posterior interventricular artery
Left coronary artery branches into:
- Anterior interventricular artery
- Circumflex artery
Three veins that drain into the coronary sinus vein which drains into the right atrium
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
__________ is composed of cardiac muscle fibers which are striated & have many similarities to skeletal muscles
myocardium
What are the differences between cardiac and skeletal striated muscle?
- Cardiac: Less extensive sarcoplasmic reticulum with no terminal cisternae
- Cardiac: Less extensive development of transverse tubules and reduced association of t-tubules with sarcoplasmic reticulum
Specialized cell-cell contact that electrically & mechanically link adjacent cells are called ___________ _______.
Intercalated Discs
Located within intercalated discs are:
Gap junctions
_______ muscle fibers contract as a single unit because they are all connected with (high/low) resistance cell-to-cell junctions that permits ion flow and allows action potentials to spread from one cell to the next.
Cardiac; low
Define autorhythmicity
The heart is capable of initiating its own heartbeat independent of external nerves
The electrical impulse that initiates the heartbeat
sinoatrial (SA) node or the pacemaker
Located on the posterior wall of the right atrium adjacent to the opening of the superior vena cava
SA node or pacemaker
SA node generates ____ to ____ impulses per minute at rest
70-80
Conducting system of the heart:
1) impulses from the SA node that travel to the left atrium and the ____________ ____ located in the floor of the _______ atrium.
atrioventricular node (AV) ; right
Conducting system of the heart:
2) Electrical activity leaves the AV node into the _____________ _____, which extends into the interventricular septum.
atrioventricular (AV) bundle
Conducting system of the heart:
3) Once within the septum, the AV bundle divides into:
left and right bundles
Conducting system of the heart:
4) Left and right bundles pass the impulse to conduction cell called ______ _____ that begin at the (apex/base) of the heart.
Purkinje fibers; apex
Conducting system of the heart:
5) The ________ ______ spread the impulse superiorly from the apex to all of the ventricular myocardium
Purkinje fibers
