Cardiovascular System and

Immune System

The function of the circulatory system is…

• Transport blood and materials in the blood (oxygen, food) around the body to the cells.

Path of blood

• Veins from the body right side of heart lungs left side of heart Arteries to the body

Arteries:

• Carry blood away from the heart• Large, elastic, muscular

Arterioles:

• Arteries branch into smaller vessels called arterioles.

Capillaries:

• Smallest blood vessels.• Very thin to allow diffusion of

oxygen, food and waste• Next to or near most cells

Venuoles:

• Capillaries combine to form venuoles

Veins:

• Venuoles combine to form veins• Have large diameters• Have valves to prevent back flow

of blood. • Return blood to heart.

Heart:

• 1. Function: pump blood• 2. Size: about the size of your fist• 3. Composition: cardiac muscle• 4. Pericardium: protective

sack/membrane around the heart. Filled with fluid to reduce friction.

The heart has four chambers

• 1. Right atrium– Recieves blood from the body

• 2. Right ventricle– Pumps blood to the lungs

• 3. Left atrium– Receives oxygenated blood from the

lungs

• 4. Left ventricle– Pumps blood to the body

• The heart is divided by the septum

• The heart is a double pump…– The right side pumps to the LUNGS

– The left side pumps to the BODY

Valves: one way path

A-V valves = valves between the atrium and ventricles

Semi-lunar valves = valves between the ventricles and main arteries.

Heart Diagram

Heartbeat Cycle:

• Diastole: heart relaxes

• Systole: heart contracts

• Heart murmur: heart valves don’t close completely and blood leaks backwards. Makes a woosh sound.

Control of the heartbeat:

• Cardiac muscle: atria contract together then ventricles contract together

• S-A node: pace-maker of the heart. Sends out electrical signals that tell the heart how fast or slow to beat.

Control of heartbeat cont.

• A-V node: sends signal to ventricles to contract

• ECG: a machine that measures the electrical impulses of the heart

• Artificial pace-maker: if your S-A node is not working, an artificial pace-maker regulates your heart beat.

Blood Pressure:

• 1. Arteries: blood pressure is highest here.

• 2. Pulse: Arteries expanding with blood.

• Sphygmomanometer: tool to measure blood pressure.

• 120/80 = normal blood pressure.

• 120 = when heart is contracting• 80 = when heart is relaxing

• What causes blood pressure to go up or down?

• Hypertension: chronic high blood pressure. Heart has to work harder.

• Arteriosclerosis: hardening of the arteries. Deposits of cholesterol.

• Vein blood pressure: lowest blood pressure. Need valves and muscle movement to move blood.

Circulation of blood• William Harvey: identified correct

pathway of blood circulation.

• Pulmonary Circulation = to lungs

• Systemic Circulation = to body– Coronary circulation = to heart– Hepatic circulation = to liver– Renal circulation = to kidneys

Blood is a fluid tissue

• Functions: Transportation

• Brings oxygen and food to cells• Removes CO2 and other wastes

from cells.• Brings hormones (chemical

messengers) to cells

Regulation: • Body temperature: heat escapes

from blood to the skin, then air.

• Blood pH is 7.4. Carbon dioxide must be removed to maintain stable pH.

• Water balance: fluids go in or out of blood depending on water needs.

Protection

• White blood cells fight infection

• Blood clots form to prevent loss of blood

Blood Components:

• Plasma:– 90% water, 10% glucose, salts, waste,

etc.

• Red Blood Cells– Function: carry oxygen to cells– Structure: Bi-concave disc, no nucleus.

They live for 4 months.– Made in bone marrow

– Hemoglobin: a protein that carries oxygen.

• White blood cells:– Defenders of the body– Has a nucleus, larger than red blood

cells– Made in bone marrow– Can move around body on its own.

– Lymphocytes: Produce antibodies which fight foreign stuff.

• Normal white blood cell count: 7000 to 10,000 /mm3

• Elevated white blood cell count when sick: 30,000/ mm3

Platelets:

• Cell fragments involved in blood clotting

• 7 day life span• Made in bone marrow

• Hemophilia: disease in which blood clotting proteins are not present so clotting won’t occur.

Circulation of Lymph

• 1. All cells of the body are bathed in a colorless, water fluid called intercellular fluid or interstitial fluid

• 2. This fluid helps to move materials between the capillaries and cells

• This fluid is made of– Water– Salts– Proteins– Nutrients

• The excess fluid and proteins from the intercellular spaces are returned to the blood by a system of vessels called the lymphatic system.

Lymph nodes or lymph glands• Filters foreign matter from lymph

fluid.

Spleen

• A lymphatic tissue that stores blood and filters out bacteria and worn out red blood cells.

Immunity Notes:

• Pathogen: microorganisms that cause disease.

• First line defenses:– Skin, sweat, saliva, mucus

• Second-line defenses:– Inflammatory response: heat,

swelling , pain, pus. – Phagocytes = white blood cells that

eat bacteria and dead cells

• Third line defenses = Immune system

• Immunity = the body fights infections by making antibodies and white blood cells that inactivate foreign substances.

• Primary immune response:– The first time a pathogen enters the

body, the body makes antibodies and fights it off.

• Secondary Immune Response:– After the body has been exposed to a

disease the body has memory cells which will quickly recognize and fight the disease.

• Active immunity: Body produces its own antibodies to fight infections.

• Vaccinations: Dead or weakened pathogens which stimulate the immune system to produce antibodies to fight the disease.

• Passive Immunity: – Antibodies are obtained from another

person (from your mom when you are a baby or from an injection when you are older)

– Temporary immunity

• Allergies: – An over reaction by the body to

normal things.

Blood Typing

All cells, including blood cells have antigens on their surface.

There are two types of antigens on blood… A or B

The body makes antibodies to fight foreign antigens.

Blood Type Antigens Antibodies (in plasma)

A A Anti-B

B B Anti-A

AB A and B none

O None Anti-A and Anti-B

Blood type Can receive from…

Can donate to…

A A and O A and AB

B B and O B and AB

AB A, B, and O AB

O O A, B and AB

• Universal Recipient = Type AB

• Universal Donor = Type O