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.
Veins
Vessels that transport
blood from the capillaries toward
the heart.
Arterioles
Small terminal
branches of an artery, which end
in capillaries.
Venules:
The very small veins
that connect capillaries to the
larger veins.
Respiratory System
A system
of organs (the lungs and
respiratory passageways) that
collects oxygen from the external
environment and transports it to
the bloodstream.
Respiratory Pump
Is
composed of skeletal structures
(bones) and soft tissues (muscles)
that work together to allow
proper respiratory mechanics to
occur and help pump blood back
to the heart during inspiration.
Inspiration
The process of
actively contracting the inspiratory
muscles to move air into the
body.
Inspiratory ventilation occurs in two forms: normal resting state (quiet) breathing
and heavy (deep, forced) breathing. Normal breathing requires the use of the primary
respiratory muscles (i.e., diaphragm, external intercostals), whereas heavy breathingrequires the additional use of the secondary respiratory muscles (scalenes, pectoralis
minor)
Expiration
The process of
actively or passively relaxing the
inspiratory muscles to move air
out of the body.
During normal breathing,
expiratory ventilation is passive as it results from the relaxation of the contracting
inspiratory muscles. During heavy or forced breathing, expiratory ventilation relies
on the activity of expiratory muscles to compress the thoracic cavity and force air out
Two Types of Respitory Passages
Conducting airways
hese structures also allow the incoming air to be
purifi ed, humidifi ed (or moisture added), and warmed or cooled to match body temperature
Nasal cavity
Oral cavity
Pharynx
Larynx
Trachea
Right and left pulmonary bronchi
Bronchioles
Respiratory airways
Diffusion occurs here and gets oxygen into the blood.
Alveoli
Alveolar sacs
Diffusion
The process of
getting oxygen from the environment
to the tissues of the body.
Oxygen Uptake (or Oxygen Consumption)
The use of oxygen by the body.
The equation for oxygen consumption is known as the Fick equation.
VO2 = Q× a–vO2 difference
Resting oxygen consumption (V·
O2) is approximately 3.5 mL of oxygen per kilogram
of body weight per minute (3.5 mL · kg−1 · min−1), typically termed 1 metabolic
equivalent or 1 MET (3,5,7,10,14–16).
Maximal Oxygen
Consumption (VO2max)
The
highest rate of oxygen transport
and utilization achieved at
maximal physical exertion.
Alteration in Breathing Patterns
If the breathing patterns become
shallow, the body uses secondary respiratory muscles more than the diaphragm, which
can negatively impact posture. This may create excessive muscular tension, resulting
in headaches, lightheadedness, and dizziness. Short, shallow breaths can also lead to
altered carbon dioxide and oxygen blood content, which causes feelings of anxiety.
Inadequate oxygen and retention of metabolic waste within muscles can create stiff
muscles and joints. If a client complains of headaches, feelings of anxiety, fatigue, poor
sleep patterns, or poor circulation, refer him or her immediately to a medical professional
for assistance.
