Download Name Period ______ Accelerated Biology The Circulatory and

Name ____________________ Period _______
Accelerated Biology
The Circulatory and Respiratory Systems
The Circulatory System Notes
Functions of the Circulatory System
 Transport system
o _______________ from digested food  all body cells
o oxygen from the lungs  all body cells
o metabolic _______________ (CO2)  organs to be excreted
o _______________  target tissues

Regulates body temperature
o in a _______________ environment blood vessels _______________, allowing more heat
to leave the body
o in a _______________ environment blood vessels _______________, preventing heat
from escaping from the body
Blood Vessels
 Arteries – carry _______________ blood _______________ from the heart
o arterioles – small arteries
o thick _______________ walls to withstand the _______________ action of the heart
o _______________ blood pressure

Capillaries – connect _______________ to _______________
o Walls are only _______ cell thick so molecules can easily
_______________ across
o Nutrients diffuse from capillaries  body cells
o Wastes diffuse from body cells  capillaries
o Capillaries are vey narrow; thickness of a single RBC

Veins – carry _______________ blood _______________ to the heart
o thin walls due to _______________ blood pressure
o have _______________ to help prevent _______________ of blood
The Heart
 A muscular pump that propels blood through the blood vessels
o Atria – two _______________ chambers that _______________ blood returning to the
heart
o Ventricles – two _______________ thick–walled chambers that _______________ blood
away from the heart
o Pericardium – _______________ sac around the heart
The Vessels
 Vena cava – _______________ veins
o Superior – drains blood from the _______________ body into right atrium
o Inferior – drains blood from the _______________ body into right atrium
 Aorta – largest artery
o comes from _______________ ventricle and branches to deliver blood to the
_______________ body
 Pulmonary arteries – carry blood _______________ the _______________ to the lungs
 Pulmonary veins – carry blood _______________ the _______________ back to the heart
 Coronary arteries – delivers blood to _______________ muscle
o When the _______________ arteries become _______________ a heart attack occurs
o Stroke – when blood supply is cut off to the _______________ and an area of the brain
dies.
The Valves
 Valves – prevent the _______________ of blood as it is being pumped through the heart
 Named according to where they _______________ or how they _______________
o Atrioventricular Valves – between the atria and ventricles
 tRicuspid – on the _______________ side
 bicuspid – on the _______________ side (a.k.a. as the _______________ v.)
o Semilunar Valves – between the ventricles and arteries
 pulmonary – right _______________  pulmonary artery
 aortic – left ventricle  _______________
Pathway of Blood through the Heart
Vena cava  right atrium tricuspid valve  right ventricle  pulmonary valve pulmonary artery 
lungs pulmonary veins left atrium  bicuspid valve  left ventricle aortic valve  aorta
Systemic Circulation
 The _______________ side of the heart pumps
_______________ blood out to the body through
a network of arteries
 _______________ blood is returned to the
_______________ side of the heart through
veins.
Pulmonary Circulation
 The right side of the heart pumps
_______________ blood through the pulmonary
arteries to the lungs.
 _______________ exchange (release of C02 and
and pick up of O2) occurs in the
_______________.
 The _______________ blood then returns to the
left side of the heart through pulmonary veins

In the pulmonary circuit the oxygen content of the vessels is _______________!
o The pulmonary _______________ carries _______________ blood away from the heart to
the lungs
o The pulmonary _______________ carries _______________ blood from the lungs back to
the heart
What Regulates Heartbeat?
 Sinoatrial (SA) node
o acts as the _______________ for the heart
o cluster of cells located in the upper wall of the _______________ atrium
o sends a rhythmic _______________ stimulus causing both _______________ to
_______________ pushing blood into the ventricles
 Atrioventricular (AV) node
o in _______________ the atria
o causes _______________ of the _______________ just after the atria contract pushing
blood out of the heart