Chapter 6: The Cardiovascular and Circulatory System
Health professionals involved in the diagnosis and
treatment of the cardiovascular system:
Cardiologist: medical doctors who specialize in the
disorders of the cardiovascular system
Cardiothoracic surgeons: perform surgeries on the heart
and other organs of the thoracic cavity
Cardiovascular surgeons: who specialize in surgery of the
heart and the major blood vessels that surround the heart
Vascular surgeons: specialize in the treatment of the
peripheral arteries and veins
Cardiac sonographers: technologists who use ultrasound
to observe the heart chambers, valves, and blood vessels
Phlebotomists: draw patient blood samples for lab testing
Perfusionists: operate on the heart-lung machine during
cardiac and other surgeries that require cardiopulmonary
bypass
The Heart
Size of your fist
Weighs 8-10 oz
Pumps around 2,000 gallons of blood each day
Heart stops working blood stops circulating tissues stop
receiving oxygen and nutrients metabolic wastes
accumulate cells die
Located in the Thoracic cavity, between the lungs in an area
called the mediastinum
Shaped like a blunt cone, pointing down and to the left
Rests at an angle with the majority of its mass to the left of
the sternum
Sternum: long, flat bone that forms the center of the
anterior wall of the chest
,Functions
Pumps blood
o As your heart contracts it generates pressure that
moves your blood forward through blood vessels
o Blood flows into the upper chambers of the heart
(atria) valves between atria and ventricles open
blood flows down into the lower chambers of the heart
ventricles contract right ventricle sends blood to
lungs/left ventricle sends blood to the rest of the body
valves close to keep the blood from going backward
Route blood
o Has 2 pumps: a right and left
o Right side sends blood through the pulmonary
circulation of your lungs and then back to the second
pump on the left side
o Left side sends blood through the systemic
circulation (relating to the entire organism) of your
body
Regulate blood supply
o The changing metabolic needs of your body [ex:
exercising] are met by changes in the rate and force of
your hearts contractions
You need more blood circulating when you are
doing strenuous activities to deliver more
nutrients to your muscles
Structure
Heart has three chambers
o Endocardium: connective tissue lining the inside of
your heart and in direct contact with blood
, o Myocardium: muscle cells that contract to enable your
heart to pump blood
o Epicardium: an outer single layer of cells overlying a
thin layer of connective tissue
Pericardium: double-layered connective tissue sac filled
with fluid that surrounds and protects the heart
o Visceral layer: inner layer that touches the heart
o Parietal layer: outer layer
Heart has 4 valves
o Tricuspid valve
o Pulmonary valve
o Bicuspid valve
o Aortic valve
The purpose of a valve is to maintain proper blood flow
through heart and to the lungs and the rest of the body
The Heartbeat
The actions of the 4 heart chambers are coordinated
Systole: contraction of the heart muscle
Diastole: dilation of the heart cavities, when they fill with
blood
When the atria contract, the ventricles relax
When the ventricles contract, the atria and ventricles relax
briefly
A complete cardiac cycle is also called a heartbeat
Electrical Properties of the Heart
Health professionals involved in the diagnosis and
treatment of the cardiovascular system:
Cardiologist: medical doctors who specialize in the
disorders of the cardiovascular system
Cardiothoracic surgeons: perform surgeries on the heart
and other organs of the thoracic cavity
Cardiovascular surgeons: who specialize in surgery of the
heart and the major blood vessels that surround the heart
Vascular surgeons: specialize in the treatment of the
peripheral arteries and veins
Cardiac sonographers: technologists who use ultrasound
to observe the heart chambers, valves, and blood vessels
Phlebotomists: draw patient blood samples for lab testing
Perfusionists: operate on the heart-lung machine during
cardiac and other surgeries that require cardiopulmonary
bypass
The Heart
Size of your fist
Weighs 8-10 oz
Pumps around 2,000 gallons of blood each day
Heart stops working blood stops circulating tissues stop
receiving oxygen and nutrients metabolic wastes
accumulate cells die
Located in the Thoracic cavity, between the lungs in an area
called the mediastinum
Shaped like a blunt cone, pointing down and to the left
Rests at an angle with the majority of its mass to the left of
the sternum
Sternum: long, flat bone that forms the center of the
anterior wall of the chest
,Functions
Pumps blood
o As your heart contracts it generates pressure that
moves your blood forward through blood vessels
o Blood flows into the upper chambers of the heart
(atria) valves between atria and ventricles open
blood flows down into the lower chambers of the heart
ventricles contract right ventricle sends blood to
lungs/left ventricle sends blood to the rest of the body
valves close to keep the blood from going backward
Route blood
o Has 2 pumps: a right and left
o Right side sends blood through the pulmonary
circulation of your lungs and then back to the second
pump on the left side
o Left side sends blood through the systemic
circulation (relating to the entire organism) of your
body
Regulate blood supply
o The changing metabolic needs of your body [ex:
exercising] are met by changes in the rate and force of
your hearts contractions
You need more blood circulating when you are
doing strenuous activities to deliver more
nutrients to your muscles
Structure
Heart has three chambers
o Endocardium: connective tissue lining the inside of
your heart and in direct contact with blood
, o Myocardium: muscle cells that contract to enable your
heart to pump blood
o Epicardium: an outer single layer of cells overlying a
thin layer of connective tissue
Pericardium: double-layered connective tissue sac filled
with fluid that surrounds and protects the heart
o Visceral layer: inner layer that touches the heart
o Parietal layer: outer layer
Heart has 4 valves
o Tricuspid valve
o Pulmonary valve
o Bicuspid valve
o Aortic valve
The purpose of a valve is to maintain proper blood flow
through heart and to the lungs and the rest of the body
The Heartbeat
The actions of the 4 heart chambers are coordinated
Systole: contraction of the heart muscle
Diastole: dilation of the heart cavities, when they fill with
blood
When the atria contract, the ventricles relax
When the ventricles contract, the atria and ventricles relax
briefly
A complete cardiac cycle is also called a heartbeat
Electrical Properties of the Heart
