Transcript Circulatory System

Circulatory System
Consists of
• Heart
• Blood Vessels
• Blood
Function
• Transports oxygen and nutrients to the
cells
• Transports carbon dioxide and metabolic
waste away from the cells
Heart
• Define
– Muscular, hollow
organ
– Size of a clenched fist
– Located in the center
of the chest, under the
sternum, tipped
slightly to the left
– Apex is the bottom of
the heart
Layers of the Heart
• Endocardium
– Epithelial tissue
– Lines heart
• Myocardium
– Middle layer
– Cardiac muscle tissue
• Pericardium
– Epithelial tissue
– Covers outside of heart
Septum
Wall that divides
the heart into left
and right
Heart Chambers
• Atria (atrium)
1. Right
3. Left
• Ventricle
2. Right
4. Left
Heart Valves
• Tricuspid
– Separates the right
atrium from the
right ventricle
– Has 3 flaps
• Mitral
– Separates the left
atria and the left
ventricle
– Has 2 flaps
• Pulmonary valve
– Separates the right
ventricle from the
pulmonary artery
• Aortic valve
– Separates the left
ventricle from the
aorta
Cardiac Cycle
• Right and left atriums
contract and work
together
• Right and left
ventricles contract
and work together
• Systole – period of
ventricular
contraction
• Diastole – brief
period of rest
Blood Pressure
120/70
• Diastolic
– Bottom number
– Heart relaxes as it
passively fills with
blood
• Systolic
– Top number
– Highest pressure in
vessels when the
ventricles contract
Pattern of Circulation
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Superior and inferior vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary valve
Pulmonary artery
Lungs
Pulmonary veins
Left atrium
Mitral valve
Left ventricle
Aortic valve
Aorta
Arteries
Arteriole
Capillaries
Venules
Veins
Superior and inferior vena cava
Electrical Conductive Pathway
• Function
– Electrical impulses in the heart cause the contraction
of the muscles
– A group of nerve cells that send out an electrical
impulse which spreads out over the heart
– SA Node
• Sinoatrial node
• Located in the right atrium
– AV Node
• Atrioventricular node
• Located in the septum between the atriums and the
ventricles
• Bundle of HIS
– Nerve cells in the
septum
• Right and Left Bundle
Branches
– Divides off Bundle of
HIS
• Purkinje Fibers
– A network of nerve
fibers throughout the
ventricles
EKG - Electrocardiogram
• Record of the
movement of the
electrical impulse as it
travels through the
heart
Normal EKG
Arrhythmias
• Abnormal or irregular
heart rhythms
Defibrillators
• When the heart is in
atrial or ventricular
fibrillation, the heart
must be shocked with
an electrical current to
stop the
uncoordinated
contraction and allow
the SA node to regain
control
Pacemakers
• A small battery powered device with
electrodes that monitors the hearts activity
and delivers an electrical impulse to
stimulate contraction
• Fixed and demand
• Avoid electromagnetic forces like
microwaves and cellular phones
Pacemakers
• Arteries
Blood Vessels
– Carry blood away from
the heart
– Largest is the aorta
– Smaller arteries called
arterioles
– After the blood leaves
the left ventricle the
first branch off the
aorta is the coronary
arteries
– Walls are more
muscular and elastic
Veins
Carry blood back to the
heart
Largest veins – superior
and inferior vena cava
Veins are thinner and
have less muscle
tissue
Valves
Veins contain valves
to prevent the
backward flow of
blood
Capillaries
One cell thick walls
Where the exchange of oxygen
and carbon dioxide takes place
Capillary Bed
Blood
• Called a tissue because it contains many
types of cells
• 4-6 quarts in the average adult
• Composed of plasma and formed
elements called blood cells
• Plasma is 90% water with dissolved
elements in it
Functions
• Carries oxygen from the lungs to the cells
and carbon dioxide from the cells to the
lungs
• Nutrients from the digestive tract to cells
• Metabolic waste from the cells to organs of
excretion
• Carries heat produced by the body
• Carries hormones to body organs
Blood Types
• O, A, B, AB
• Rh factor positive or negative
Universal Donor
O+
Universal Recipient
AB+
Blood Types
•
Out of 100 people, about:
• 38 will be O +
• 7 will be O • 34 will be A +
• 6 will be A • 8 will be B +
• 2 will be B • 4 will be AB +
• 1 will be AB -
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Who Can Receive Whose Red Blood
Cells:
• O - can only use O • O + can use O + or O • A - can use A - or O • A + can use A +, A -, O + or O • B - can use B - or O • B + can use B +, B -, O + or O • AB - can use AB -, A -, B - or O • AB + can use All Blood Types
Agglutination
Blood Cells
• Erythrocytes
- Red Blood Cells RBC
– Function to carry oxygen
and carbon dioxide
– Live for 120 days
– Shaped like a doughnut
– Contains hemoglobin – a
blood protein
– Amount of hemoglobin
gives blood its red color
– Carries the O2 and CO2
Leukocytes
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White blood cells - WBC
Function – fight infection
Live 3-9 days
Fight infection by
phagocytes
• 5 types of leukocytes
Phagocytosis
Thrombocytes
• Thrombocytes
– Platelets
– Cell fragments
– Formed in the bone
marrow
• Function
– Clotting
– Thrombus is a stationary
clot
– Embolus is a moving clot
• Live
– 5 to 9 days
Diseases
• Anemia
– Too little RBS’s or
hemoglobin or both
– Many types
Sickle Cell Anemia
Aplastic anemia
Pernicious anemia
Iron deficiency
anemia
Sickle Cell Anemia
• Chronic inherited
anemia
• Occurs almost
exclusively in African
Americans
• Cells are abnormally
shaped like a sickle
• Crisis occur when
they block the vessels
and severe pain
results
Aneurysm
• A ballooning out or
weakness of an artery
wall
• Usually asymptomatic
• May rupture and
hemorrhage and
death results
• Repair is possible if
diagnosed early
Common Aneurysm Sites
Cerebral, Aortic, Abdominal
Repair of an Aneurysm
Arteriosclerosis
• Hardening of the
arteries
• Results in the loss of
elasticity and
contractility
• Results of aging
• Causes hypertension
Atherosclerosis
• Deposits of plaque on
artery wall
• If plaque breaks loose
circulates as an
emboli and
Surgical Repair
• CABG
– Coronary artery
bypass graft
– A vein from the leg or
chest is used to go
around or “bypass” the
blockage
Stent
• Insertion of an
expandable coil
that
• Keeps the vessel
open
• Some are
medicated
Hemophilia
• Inherited disease that
occurs mostly in
males but carried by
females
• Lack of a clotting
factor (VII most
common)
• Minor cut can cause
prolonged bleeding
Hypertension
• Increased blood
pressure
• Caused by a
narrowing of the
vessels or too much
fluid in the vessel
• Controlled with
medication and diet
very effective
• Leading cause of
stroke
Hypotension
• Low blood pressure
• Due to dilation of the
blood vessels, shock,
or hemorrhage
Leukemia
• Cancer of the bone
marrow or lymph
tissue
• Results in a high
number of immature
WBC”s
• Treatment
– Radiation, chemo,
bone marrow
transplant
Myocardial Infarction
• Heart Attack
• Due to blockage in
the coronary arteries
that cuts off the blood
supply to the heart
• Treatment includes
clot busting drugs,
CABG, stents
Phlebitits
• Inflammation of a vein
• If caused by a clot it is
called
thrombophlebitis
Varicose Veins
• Dilated, swollen veins