Download circulatory system

CIRCULATORY SYSTEM
Anatomy of the Heart
• The human heart is a muscular pump
composed of cardiac muscle that allows for
continued rhythmic contraction.
• Cardiac muscle is a involuntary muscle,
meaning it does not need to be told to
contract.
• It is located in the middle of your chest right
behind the sternum and just to the left.
• It is the size of your fist.
Anatomy of the Heart
• There are four chambers in the heart - two
atria and two ventricles.
Assignment: Color the heart diagram
Protective Layers of the Heart
• The heart is encased in two protective layers.
The outer layer - the pericardial sac - covers
the heart.
Protective Layers of the Heart
• While the epicardium forms the outer layer of
the heart, the myocardium forms the middle
layer and the endocardium the innermost
layer.
• The coronary arteries - arteries that provide
blood to the heart's own cells - travel across
the epicardium.
• The muscular myocardium is the thickest layer
and the workhorse of the heart.
• The endocardium has a smooth inner surface
to allow blood to flow easily through the
heart's chambers.
• The heart's valves are also part of the
endocardium.
Parts of the Heart
• The atria (one is called an atrium) are
responsible for receiving blood from the veins
leading to the heart. When they contract, they
pump blood into the ventricles
• The ventricles are the real workhorses, they
must force the blood away from the heart
with sufficient power to push the blood all the
way back to the heart.
• Between the atria and the ventricles are
valves
• These are overlapping layers of tissue that
allow blood to flow only in one direction.
•
Assignment: Define each of the valves in the heart.
VALVES
• The tricuspid valve is between the right
atrium and right ventricle.
• The pulmonary or pulmonic valve is between
the right ventricle and the pulmonary artery.
• The mitral valve is between the left atrium
and left ventricle.
• The aortic valve is between the left ventricle
and the aorta.
Heart valves
• 4 valves in the heart
– flaps of connective tissue
– prevent backflow
SL
• Atrioventricular (AV) valve
– between atrium & ventricle
– keeps blood from flowing back
into atria when ventricles pump
– “lub”
• Semilunar valves
– between ventricle & arteries
– prevent backflow from arteries into
ventricles
– “dub”
AV
AV
Lub-dub, lub-dub
• Heart sounds
– closing of valves
– “Lub”
SL
• force blood against
closed AV valves
– “Dub”
AV
AV
• force of blood against
semilunar valves
• Heart murmur
– leaking valve causes hissing sound
– blood squirts backward through valve
Cardiac cycle
• 1 complete sequence of pumping
– heart contracts & pumps
– heart relaxes & chambers fill
– contraction phase
• systole
• ventricles pumps blood out
– relaxation phase
• diastole
• atria refill with blood
Electrical signals
allows atria to empty
completely before
ventricles contract
stimulates ventricles
to contract from
bottom to top, driving
blood into arteries
• heart pumping controlled by electrical impulses
• signal also transmitted to skin = EKG
Cardiac Cycle
How is this reflected in blood
pressure measurements?
systolic
________
diastolic
pump
(peak pressure)
_________________
110
________
fill (minimum pressure) 80
What is the Circulatory System ?
• The system of the body responsible for internal
transport. Composed of the heart, blood vessels,
lymphatic vessels, lymph, and the blood.
• The Circulatory Systems is a combination of
vessels and muscle that help and control the flow
of blood around the body.
• This is known as CIRCULATION.
Circulatory systems
• All animals have:
– muscular pump = heart
– tubes = blood vessels
– circulatory fluid = “blood”
open
hemolymph
closed
blood
Evolution of circulatory system
Not everyone has a 4-chambered heart
fish
2 chamber
amphibian
3 chamber
reptiles
3 chamber
birds & mammals
4 chamber
Birds AND
mammals!
Wassssup?!
V
A
A
A
V
A
V
A
V
A
V
A
V
Evolution of circulatory systems
• What advantage was a
4-chambered heart
– increase body size
– fuel warm-blooded
– enable flight
• Higher energy needs
– greater need for energy, fuel,
O2, waste removal
• warm-blooded animals & flying
need 10x energy
• need to deliver 10x fuel & O2
convergent
evolution
The Main Parts of the Circulatory SystemHumans (Vertebrates)
• The main parts of the Circulatory System
include:
• The Heart
• Arteries (within the heart also)
• Veins
• Capillaries
ASSIGNMENT:
Define each part of the Circulatory System
ARTERIES:
Pulmonary Artery, Aorta, Coronary Artery, Carotid Artery,
Femoral Artery, Arteries in General
VEINS:
Superior Vena Cava, Inferio Vena Cava, Jugular Vein, Coronary
Vein, Pulmonary Vein, Veins in General
CAPILLARIES
BLOOD
• What is blood made of?
• Blood is a mixture of cells and a watery liquid,
called plasma, that the cells float in.
• Plasma is about 90 percent water.
• 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
fight infection, and platelets help in clotting.
• Red blood cells (also called erythrocytes) are
the most numerous, making up 40-45 percent
of one's blood, and they give blood its
characteristic color. Red blood cells are shaped
like tiny doughnuts, with an indentation in the
center instead of a hole.
• What is HEMOGLOBIN?
• Hemoglobin is a special molecule which
carries the oxygen that is found in the blood.
• Where there is a lot of oxygen, in the lungs,
the hemoglobin molecules loosely bind with
oxygen.
• Each molecule of hemoglobin contains four
iron atoms, and each iron atom can bind with
one molecule of oxygen, allowing each
hemoglobin molecule to carry four molecules
of oxygen.
• What makes our blood RED?
• The iron in hemoglobin is what makes blood
red.
Types of Blood
• If the red blood cell had only "A" molecules
on it, that blood was called type A.
• If the red blood cell had only "B" molecules on
it, that blood was called type B.
• If the red blood cell had a mixture of both
molecules, that blood was called type AB.
• If the red blood cell had neither molecule,
that blood was called type O.
Transfusions/Donations
• A person with type A blood can donate blood
to a person with type A or type AB. A person
with type B blood can donate blood to a
person with type B or type AB. A person with
type AB blood can donate blood to a person
with type AB only. A person with type O blood
can donate to anyone.
• What happens when different types of blood
mix?
• If two different blood types are mixed together, the
blood cells may begin to clump together in the blood
vessels, causing a potentially fatal situation.
• it is important that blood types be matched before
blood transfusions take place.
• In an emergency, type O blood can be given because
it is most likely to be accepted by all blood types.
However, there is still a risk involved.
Cardiovascular diseases
• Atherosclerosis & Arteriosclerosis
– deposits inside arteries (plaques)
• develop in inner wall of the arteries,
narrowing their channel
– increase blood pressure
– increase risk of heart attack, stroke, kidney damage
normal artery
hardening of arteries
Cardiovascular healthbypass surgery
• Genetic effects
• Diet
– diet rich in animal fat increases risk of CV disease
• Exercise & lifestyle
– smoking & lack of exercise increases risk of CV
disease
Cardiovascular health
Heart Disease
696,947
Cancer
557,271
Stroke
162,672
Chronic lower respiratory diseases
124,816
Accidents (unintentional injuries)
106,742
Diabetes
73,249
Influenza/Pneumonia
65,681
Alzheimer's disease
58,866
Nephritis, nephrotic syndrome &
nephrosis
40,974
Septicemia
33,865
Heart Disease
Heart disease death rates
Adults ages 35 and older
Women & Heart Disease
Death rates for heart disease per 100,000 women
Risk factors
 Smoking
 Lack of exercise
 High fat diet
 Overweight
• Heart disease is 3rd leading cause of death among
women aged 25–44 years & 2nd leading cause of
death among women aged 45–64 years.
Assignment
• What is the role of the Cardiovascular System in
achieving and maintaining wellness?
• Explain the effects of aging and lifestyle choices on
the Cardiovascular System
• What impact does the Cardiovascular System have
on the other Systems of the body
• Explain/describe the social, emotional, and economic
impact of respiratory/cardiovascular conditions on
the individual, family, peers and community
• Evaluate preventative lifestyle choices required for
Cardiovascular Wellness
27-40
Diseases and Disorders of the
Cardiovascular System
Disease
Description
Anemia
The blood does not have enough red blood cells
or hemoglobin to carry an adequate amount of
oxygen to the body’s cells
Aneurysm
A ballooned, weakened arterial wall
Thrombophlebitis Blood clots and inflammation develops in a vein
Thalassemia
Murmurs
Inherited form of anemia; defective hemoglobin
chain causes, small, pale, and short-lived RBCs
abnormal heart sound due to valves not
functioning properly
27-41
Diseases and Disorders of the
Cardiovascular System (cont.)
Sickle Cell
Anemia
Abnormal hemoglobin causes RBCs to change
to a sickle shape; abnormal cells stick in
capillaries
Hypertension
High blood pressure; consistent resting blood
pressure equal to or greater than 140/90 mm Hg
Heart Disease
• Endocarditis –
inflammation of the
endocardium
• Myocarditis – inflammation
of the heart muscle
• Pericarditis – inflammation
of the pericardium, the sac
which surrounds the heart
Bacterial Endocarditis
Congenital Heart Disease
• Patent Foramen Ovale – hole
present between the 2 atria fails
to close at birth
• Patent Ductus Arteriosis – duct
between the pulmonary artery
and the aorta fails to close at birth
• Coarctation of the Aorta –
localized narrowing of the arch for
the aorta
• Tetralogy of Fallot – combination
of 4 defects that occur together,
“blue baby”
Tetralogy of Fallot
Rheumatic Heart Disease
• Toxins produced by
streptococci affect the
valves of the heart so
they do not open
completely (mitral
stenosis) or close
completely (mitral
regurgitation)
Coronary Heart Disease
• Coronary occlusion Coronary arteries
become clogged;
therefore, not as much
blood goes to the heart
muscle. If an artery is
completely clogged, it
leads to ischemia, a lack
of blood supply to an
area.
Blocked Arteries
Coronary Heart Disease Cont’d
• Thrombus – blood clot, can
clog coronary arteries
• Infarct – an area that has been
cut off from its blood supply
• Myocardial Infarction – heart
attack
• Angina Pectoris – pain felt due
to inadequate blood flow to the
heart (pain in heart, left arm,
and shoulder)
Rhythm Abnormalities
• Arrhythmia – abnormality in the
rhythm of the heart
• Flutter – rapid, coordinated
contractions up to 300 per min
• Fibrillations – extremely serious,
rapid, irregular contractions
• Heart Block – interruption of
electrical conduction
Congestive Heart Failure
• Many times caused by
hypertension
• Causes enlargement of
heart
• Heart unable to pump
effectively because it is
weak
– Kidneys save fluid
– Edema
– Short of breath
Rhythm Abnormalities
• Arrhythmia – abnormality in the
rhythm of the heart
• Flutter – rapid, coordinated
contractions up to 300 per min
• Fibrillations – extremely serious,
rapid, irregular contractions
• Heart Block – interruption of
electrical conduction
Medications
• Digitalis – slows contractions and helps
heart beat stronger, from foxglove plant
• Nitroglycerin – dilates blood vessels to
the heart: improves circulation
• Antiarrhythmics – regulate heart
rhythm and rate
• Anticoagulants – prevent clotting
(heparin & coumadin)
• Beta Blockers – adrenergic blocking
agents decrease rate & strength of
heart contractions reducing the heart’s
oxygen demand (propanolol)
Instruments Used for Heart Study
• Stethoscope: used to listen to heart
sounds
• EKG: records electrical activity as
waves
• Heart Catheterization: thin tube
inserted into heart for blood
samples, pressure readings, etc.
• Fluoroscope: examines deep tissue
with x-rays
• Echocardiogram: uses ultrasound to
record picture of heart in action