Chapter 3 Flashcards
Heart
A hollow muscular
organ that pumps a circulation
of blood through the body by
means of rhythmic contraction.
It is divided into four chambers: two atria (which gather blood
from the body) and two ventricles (which pump blood out to the body) on each side.
Mediastinum
The space in
the chest between the lungs that
contains all the internal organs of
the chest except the lungs.
Sinoatrial (SA) Node
A
specialized area of cardiac tissue,
located in the right atrium of the
heart, which initiates the electrical
impulses that determine the
heart rate; often termed the
pacemaker for the heart.
Atrioventricular (AV) Node:
A small mass of specialized cardiac
muscle fi bers, located in the wall of
the right atrium of the heart, that
receives heartbeat impulses from
the sinoatrial node and directs
them to the walls of the ventricles.
Atrium
The superior chamber
of the heart that receives blood
from the veins and forces it into
the ventricles.
Atria
Smaller chambers, located superiorly (on top) on either side of
the heart. They gather blood returning to the heart, and act much like a reservoir.
Ventricles
The inferior
chamber of the heart that receives
blood from its corresponding
atrium and, in turn, forces blood
into the arteries.
Stroke Volume
The amount of
blood pumped out of the heart
with each contraction.
Heart Rate (HR)
The rate at
which the heart pumps.
Cardiac output (Q )
Heart
rate × stroke volume, the overall
performance of the heart.
Blood
Fluid that circulates in
the heart, arteries, capillaries,
and veins, carries nutrients and
oxygen to all parts of the body,
and also rids the body of waste
products.
Blood consists of cells suspended in a watery liquid called
plasma that also contains nutrients such as glucose, hormones, and clotting agents.
There are three kinds of cells in the blood, red blood cells, white blood cells, and platelets.
Red blood cells carry oxygen from the lungs throughout the body, white blood cells
help fi ght infection, and platelets help with clotting
Support Mechanisms of Blood
Transportation
Transports oxygen and nutrients to tissues
Transports waste products from tissues
Transports hormones to organs and tissues
Carries heat throughout the body
Regulation
Regulates body temperature and acid balance in the body
Protection
Protects the body from excessive bleeding by clotting
Contains specialized immune cells to help fi ght disease and sickness
Blood Vessels
Network of
hollow tubes that circulates
blood throughout the body.
Arteries
Vessels that transport
blood away from the heart.
Capillaries
The smallest blood
vessels, and the site of exchange
of chemicals and water between
the blood and the tissues.