Circulatory System

How long does it take a red blood cell to circulate the whole body?

about 20 seconds

What is the circulatory system also known as?

cardiovascular system

What does the circulatory system consist of?

heart, blood vessels, blood

What is the circulatory system often referred to as?

the transportation system because it transports oxygen and nutrients to the body's cells and transports wastes away from the body's cells

the heart

muscular, hollow organ

What is the heart often called?

the pump of the body

How much does your heart weigh?

about 1 pound

How big is your heart?

about the size of your fist

How many times a day does your heart contract?

about 100,000 times to pump the equivalent of 2,000 gallons of blood through the body

Where is the heart located?

between the lungs and rotated to the left

How many layers are in your heart?

3

Endocardium

-smooth layer of cells

-lines inside of the heart and is continuous with the inside of blood vessels

-allows for smooth flow of blood

Myocardium

thickest layer, muscular middle layer

Pericardium

-double layered membrane or sac

-covers outside of the heart

What fills the space between the layers of the pericardium?

pericardial fluid that prevents friction and damage to membranes as the heart beats, or contracts

the septum

muscular wall

What does the septum separate?

the heart into right and left sides

What is the upper part of the septum called?

interatrial septum

What is the lower part of the septum called?

interventricular septum

How many chambers are in the heart?

four

right atrium

receives blood as it returns from the body

right ventricle

receives blood from the right atrium and pushes blood into the pulmonary artery, which carries the blood to the lungs for oxygen

left atrium

receives oxygenated blood from the lungs

left ventricle

receives blood from the left atrium and pushes blood into the aorta so it can be carried to the body

How many valves are in the heart?

four

Where is the tricuspid valve located?

between right atrium and right ventricle

When does the tricuspid valve close?

the right ventricle contracts and pushes blood to the lungs

What does the tricuspid valve do?

prevents blood from flowing back into the right atrium

Where is the pulmonary valve located?

between the right ventricle and pulmonary artery, a blood vessel that carries blood to lungs

When does the pulmonary valve close?

when right ventricle has finished contracting and pushing blood into pulmonary artery

What does the pulmonary valve prevent?

blood from flowing back into the right ventricle

Where is the mitral valve located?

between the left atrium and left ventricle

When does the mitral valve close?

when left ventricle is contracting and pushing blood into aorta so blood can be carried to the body

What does the mitral valve do?

prevents blood from flowing back into the left atrium

Where is the aortic valve located?

between left ventricle and aorta

Largest artery in the body

aorta

When does the aortic valve close?

when left ventricle is finished contracting and pushing blood into the aorta

What does the aortic valve do?

prevents blood from flowing back into the left ventricle

cardiac cycle

right and left sides of heart work together in cyclic manner even though they are separated by the septum

electrical impulse originating in the heart causes myocardium to contract in a cyclic manner

diastole

brief period of rest in the heart

dub

closing of the semilunar valves (pulmonary and aortic valves)

systole

contraction that follows diastole

lub

closing of the AV valves (mitral and triscuspid)

heart sounds

lub dub

circulation of blood through the heart

vena cavas, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary artery, lungs, pulmonary vein, left atrium, bicuspid valve, left ventricle, aortic valve, aorta, body

What happens at the start of the cardiac cycle?

atria contract and push blood into the ventricles, then the atria relax

What happens when the atria are filling?

systole begins and ventricles contract

blood in the right side of the heart

Low oxygen and high carbon dioxide

Where does the oxygenated blood go?

left side of the heart

What are abnormal heart sounds due to?

improper opening or closing of the valves AKA a murmur

cardiac arrhythmia

interference with normal electrical conduction pattern of the heart and causes abnormal heart rhythms

Premature atrial contraction(PAC)

an early contraction of the atria, can occur in anyone and usually goes unnoticed

Ventricular fibrillation

ventricles contract at random without coordination, decreases or eliminates blood output and causes death if not treated

What is used to diagnose arrhythmias?

Cardiac monitors and electrocardiograms

defibrillation(AED)

device that shocks the heart with electrical current

stops the heart momentarily

allows SA node to regain control

treatments of arrhythmias

External or internal artificial pacemakers

blood vessels

carries the blood that leaves the heart throughout the body

What two things form a closed system for flow of blood?

heart and blood vessels

3 manin types of blood vessels

arteries, veins, and capillaries

How does blood travel through the blood vessels?

heart -> artery -> arterioles -> capillary -> venule -> vein -> heart

arteries

carry oxygenated blood away from the heart

more muscular and elastic than other blood vessels because they receive blood as it is pumped from the heart

aorta

receives blood from left ventricle of the heart

branches off into other arteries that supply blood to the body

arterioles

Smallest branches of arteries

joins with the capillaries

veins

Blood vessels that carry blood away from the body to the heart

thinner than arteries and have much less muscle tissue

superior and inferior vena cava

Two largest veins that drain into the right atrium

Venules

Smallest branches of veins that connect with capillaries

cappilaries

Connect arterioles with venules

located in close proximity to almost every cell in the body

have thin walls that contain only one layer of cells

allow oxygen and nutrients to pass through to the cells

at the same time, carbon dioxide and metabolic products from the cells enter the capillaries

What is blood often called?

a tissue because it contains many types of cells

about how many quarts of blood are in each adult?

4-6

blood

Transports many substances:

Oxygen from the lungs to body

Carbon dioxide from body to lungs

Nutrinets from digestive tract to cells

Metabolic waste products from cells to organs of excretion

Heat produced by various body parts

Hormones produced by endocrine glands to organs in the body

plasma

Fluid or liquid portion of blood

Consists of about 90% H2O

Many substances are dissolved or suspended in the water

blood cells

AKA corpuscles, are the solid elements of blood

3 main types of blood cells

erythrocytes, leukocytes, thrombocytes

Erythrocytes(red blood cells)

Produced in the red bone marrow at a rate of about 1 million per minute

Live about 120 days before being broken down by the liver and spleen

Mature form circulating in blood does not have a nucleus and is shaped like a disc with thinner central area

What protein is in erythrocytes?

hemoglobin

Leukocytes(white blood cells)

Not as numerous as erythrocytes

Formed in the bone marrow and lymph tissue and usually live about 3 to 9 days

Leukocytes can pass through caillary walls and enter body tissue

Main function is to fight infection

Phagocytosis

process by which some leukocytes engulf, ingest, and destroy pathogens, or germs

Thrombocytes(platelets)

Usually described as fragments or pieces of cells

Do not have a nucleus

Vary in shape and size

Formed in bone marrow and live about 5-9 days

Important for the clotting process which stops bleeding

blood doping

the practice of boosting the number of red blood cells in the bloodstream in order to enhance athletic performance

anemia

Inadequate number of erythrocytes hemoglobin, or both

Hemoglobin carries O2 tissues and organs

Decrease in hemoglobin can cause hypoxia, a lack of oxygen supply

symptoms of anemia

paleness, fatigue, dyspnea, rapid HR

anuerysm

Ballooning out or saclike formation on wall of artery

causes of anuerysm

disease, high BP, congenital defects, injuries leading to a weakening structures of wall of artery

symptoms of aneurysm

some cause pain and pressure, some have no Sx at all

Treatments of aneurysms

risks of surgical repair are similar to risks of rupture, so watchful waiting approach with control of BP is often used

arteriosclerosis

Hardening or thickening of arterial walls

Causes loss of elasticity and contractility

Commonly occurs as a result of aging

Causes hypertension and can lead to aneurysm or cerebral hemorrhage

Main focus of treatment is lowering blood pressure through the use of diet and/or medications

Atheriosclerosis

Fatty plaques, frequently cholesterol, deposited on wall of arteries

Lack of blood flow to the heart, brain, or extremitites can cause a heart attack, stroke or gangrene

If plaques break loose, they can circulate through blood stream as emboli

Treatments of atherosclerosis

ow-cholesterol diet, medications to lower BP and cholesterol blood levels, abstaining from smoking, reduction of stress, and exercise

congestive heart failure

Heart muscles do not beat adequately to supply blood needs to the body

May involve right or left sides of the heart

Risk factors include high blood pressure, high cholesterol, obesity, and diabetes

symptoms of congestive heart failure

edema, dyspnea, pallor or cyanosis, distention of the neck veins, weak and rapid pulse, cough with pink frothy sputum

treatments of congestive heart failure

Cardiotonic drugs to slow and strengthen heartbeat

Diuetics to remove fluid

Elastic support hose to improve circulation

Oxygen therapy

Weight loss/low-sodium diet

Exercise

embolus

Foreign substance circulating in blood stream

Can be air, blood clot, bacterial clumps, fat globule

Blockage of vessel occurs when embolus enters an artery of a capillary too small for passage

Hemophilia

Inherited disease occurs almost exclusively in males but carried by females

Blood not able to clot due to lack of plasma protein

treatments of hemophilia

life long disease with no cure

hypertension

High BP

Systolic pressure above 140 to 150 mm

Diastolic pressure above 90 mm

treatments of hypertension

no cure

Antihypertensive drugs

Diuretics to remove retained body fluids

Decreased stress and avoiding tobacco

Low-soium or low-fat diet

Leukemia

Malignant disease(cancer) of bone marrow or lymph tissue

Results in large number of immature or abnormal white blood cells that do not function properly to fight infection

Different types of leukemia: some acute, some chronic, some common in children while other more prominent in adults

symptoms of leukemia

fever, frequent infections, pallor, swelling of lymphoid tissues, persistent fatigue, anemia, bleeding gums, excessive bruising, joint pain

myocardial infarction(heart attack)

Blockage in the coronary arteries cuts off supply of blood to the heart

Lack of blood flow can cause ishemia, tissue injury, or tissue death

Acute coronary syndrome is a term used to identify patients who are suspected of having myocardial ishemia

With myocardial infarction, death can occur immediately if large area is affected

symptoms of myocardial infarction

severe crushing pain that radiates to arm neck, and jaw

Pressure in the chest

Perspiration and cold, clammy skin

Dyspnea

A sense of doom

Change in blood pressure

Immediate Treatment of a Myocardial Infarction

CPR & AED if heart stops

“clot-busting” drug to restore blood flow to the heart, must be used in the first several hours. Prohibited if bleeding is present

phlebitis

Inflammation of vein, frequently in leg

Thrombophlebitis if clot forms in a vein near the surface of the skin

Deep vein thrombosis if deep in a muscle

Blood clots are often a result of prolonged sitting or immobility