Chapter 3 Flashcards
Heart
hollow, muscular organ that pumps a circulation of blood through the body by means of rhythmic contraction
Mediastinum
space in the chest between lungs that contains all internal organs of the chest except lungs
Adult heart size
size of the fist that weighs 300g
Cardiorespiratory system
composed of the respiratory and cardiovascular system
Cardiovascular system
blood vessels, blood and the heart
Arteries
carry blood away from the heart to the rest of the body
Veins
return blood to the heart from the rest of the body
Stroke volume
the amount of blood pumped out of the heart with each contraction
Cardiac output
heart rate x stroke volume
Average blood volume for an adult
4-6L of blood
Sinotrial (SA) node
pacemaker for the heart
Atrioventricular (AV) node
small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart
Heart rate
70-80 BPM
Atrium
superior chamber of the heart that receives blood from veins and forces it into ventricles. located on the either side of heart and gathers blood returning to heart.
Right atrium
gathers deoxygenated blood
Left atrium
gathers oxygenated blood from lungs
Ventricle
inferior chamber of the heart that receives blood from its corresponding atrium and forces blood into arteries. larger than the atrium
Right ventricle
has thin walls and pumps under low pressure
Left ventricle
has thicker walls and pumps under high pressure because it pumps blood out to the rest of the body
Respiratory system
lungs and respiratory passageways that collect oxygen from the external environment and transport it to the blood stream
Inspiration
inhalation. actively contracting the inspiratory muscles to move air into the body
Expiration
exhalation. process of actively or passively releasing inspiratory muscles to move air out of the body
Respiratory pump
the thoracic and abdominal structures that help with the contraction and expansion of the lungs
Muscles for inhalation
scalene muscles, the pectoralis minor, sternocleidomastoid, and the diaphragm
Muscles of exhalation
internal intercostals, abdominal muscles
Resting oxygen consumption (VO2)
approx 3.5 mL of oxygen per kg of bodyweight per minute. 1 MET
Maximal oxygen consumption (VO2max)
highest rate of oxygen transport and utilization achieved at maximal physical exertion
