The Circultory System

The Four Key Functions of the Circultory System

1. Transport and deliever oxygen throughout the body

2. distribute heat

3. defend diesase

4. transport and deliver chemical messengers

The Cardiovascular System

Involves two components working together to move nutrients and oxygen throughout the body

1. Cardio refers to the heart

2. Vascular- Refers to the blood vessels (capillaries, veins, arteries)

Arteries

Thick walled blood vessels that carry blood away from the heart (mainly oxygenated as it mainly carries blood to body

Veins

Thin- walled blood vessels, mainly deoxygenated and carry blood towards the heart

Capillaries

One cell thick blood vessel that is the site of gas exchange (diffusion)

Pulmonary

Vessels that carry blood towards the lungs

Systemic

Vessels that carry blood to the systems of the body

How many times does the heart beat per day

80,000

The heart

The organ that keeps the blood in our body in constant motion delivering oxygen and nutrients to the systems and cells of our body

The four chambers

right Ventricle- pumps blood to the lungs out through the pulmonary artery

right atrium- receives deoxygenated blood from the body through the superior and inferior vena cava, pumping it into the right ventricle

left Ventricle- muscular ventrcle that recives oxygenated blood from the right atrium and pumps it to the body through the aorta

left atrium- recives oxygenated blood from the pulmonary vein and pumps it into the right ventricle to be pumped to the body

Atrioventricular Valve

Valve that seperates the atria from the ventricle preventing backflow from ventricle into atria

Semilunar valve

found in areas where blood vessels attach to the ventricle

Myogenic Muscle

This is what the heart is made of. It can beat on its own without any external input (done with an internal pacemaker that supplies the constant electric signal.

The failure of a pacemaker

When a pacemaker fails, a doctor will install an artificial pacemaker. This device sends electical signals telling the heart to beat

Heart Beats

Disostale (downstairs) the heart relaxation. Phase of a heart cycle where the atria or ventricle is filling with blood

Systole (Squeeze)- heart contration. Atria contract and push blood into ventricle while the ventricle contracts and pushes blood to the body or to the lungs

Lub

Closing of AV valves within the heart

Dub

Closing of the semilunar valves (ventricles contract sending blood to your arteries)

Heart Murmur

Faulty heart valves that allow the backflow of blood into the heart chambers

Gurgling sounds

Faster heart rate

larger contraction

Factors affecting heart rate- Emotions

fear, flight or fright increases adrenaline which circulates glucose to muscles

Factors affecting heart rate- Temperature

heart rate increases to help distribute heat to the outside body dilating the blood vessels

Factors affecting heart rate- exercise

cardiovascular exercise strengthens the heart as it has to pump faster to get nutreints (glucose) and oxygen to the parts of the body that need it the most.

Factors affecting heart rate- disorders

atherosclerosis- buildup of plaque in the walls of arteries leading to an increase in blood preassure and lack of O2 in tissues

Stroke Volume

Blood pumped per beat

Female- 60 ml

Male- 70 ml

resting rate- 72 bpm

Cardiac Output

blood pumped per minute

Vena Cavae

The largest vein the body that carries deoxygenated blood from the body

Pulmonary Artery

Large blood vessel that carries deoxygenated blood from ventricle to lungs

Pulmonary Vein

Large blood vessel that carries oxygenated blood from the lungs to the heart (left atrium)

Aorta

The largest artery in your body that carries oxygenated blood to the body from the heart

The flow of blood (Arteries, arterioles, venules, veins)

blood leaves the heart through arteries which create a pulse (expansion of artery wall due to preassure creating a pulse) (always oxygenated excpet pulmonary artery) arteries that are further away from the heart turn into

arterioles- smaller and lower and preassure, they attach to thin wall capillaires where nutrients and oxygen are exchanged for wastes

Capillaries exist in capillary beds that surround many cells of the body

blood leaves the capillaries through low preasure venules which eventually lead to low preasure veins

Veins have

Veins have valves that open in one direction to avoid backflow and prevents pooling. When blood collects in a vein skeletal muscles push it towards the heart

Varicose veins

Form when veins become stretched and damaged. Blood will start to pool and veins become raised

Cardiovascular disease

A blanket term for many different disorders involing the blood vesssels and heart

Atherosclerosis

Hardening of arteries due to an accumulation of fatty deposits

Cornay Heart Disease

restricted blood flow through cornary arteries

Heart Attack

clot in a cornary artery cuts off blood supply to heart muscle casuing the tissue to die

Stroke

Sudden loss of brain function casued by an interruption in blood flow to the brain

anaysm

bulging or weakness in the wall of artery or vein

Valvular Heart Disease

diseases of heart valves leading to narrowing, leaking or improper closing of the heart valves

Septal Heart defect

Opening within septum that allows blood to flow between the left and right ventricle

Cholesteral

A vital component of cell membranes and key production of hormones

Plaque

Occurs when the concentation of Cholsteral becomes too high in our arteries and causes it to build up which can lead to a decrease in blood flow.

Plaque buildup can also promote blood clotting which can complety block off blood vessels leading to heart attacks or strokes

Low Density Lipo- proteins (LDL)

carries cholersteral from liver to body cells. considered bad cholesterol for plaque buildup

High Density Lipo-proteins (HDL)

Carries cholsteral to liver to be excreated. Considered good because it results in the removal of cholesterol from the blood stream

Blood Preassure

Preassure exterted by blood against the walls of blood vessels such as arteries. measured with a sphygmomanometer

Sphygmomanometer

The tool that measures blood preassure

The cuff closes off flow in the brachial artery and will deflate until a sound is heard

Systolic Preassure

The first sound you hear when testing blood preassure- it is the sound of the ventricles contracting. It is normally around 120mm/Hg

Diastolic Preasure

Happens after the systolic preassure disappears. This is when the ventricles are relaxed and filing

Average Adult Blood Preassure

120mmHg/80mmHg

Why does blood preassure change after excerise

When you exercise your heart works harder to get blood faster to the parts of the body that need it most, which causes more blood to flow through

What is blood made of?

• 50% Plasma (fluid portion of blood) mainly water

• 42-45% Red Blood cells

• 5% white blood cells and Platelets

Eythrocytes

Transport oxygen from the lungs to body cells

formed by stem cells in bone marrow

Bioconcave disks -no nucleus, short lifespan, and contains hemoglobin

Disorder of Eyrthocytes (anemia)

reduced blood oxygen due to low RBCs or lack of hemoglobin

Leukocytes

Apart of the bodies defence mechanism against pathogens

Have a role of englulfing invading cells through phagocytosis as well as the digestion of the microbe which creates pus.

pus- used up WBCs and dead tissue and bacteria

Have a nucleus, no uniform size or shape (largest of all blood vessels), originate from stem cells

Disorder of Leukocytes (Leukemia)

An individuals leukocyte count increases but the cells do not function

Platelets

Initiate blood clotting and orignate from stem cells

small, fragile, and contain specialized proteins (thromboplastin)

Blood clotting step 1

Platelets moving through a damaged blood vessel rupture and clump together

Blood clotting step 2

Platelets release a protein that binds with calcium to activate various chemical reactions

Blood clotting step 3

Fibringogen is activated by the chemicals forming Fibrin which are thread like proteins

Blood clotting step 4

Fibrin weaves itself into a mesh covering that traps eyrthocytes forming a blood clot

Hemophillia

A gentic blood disorder that reduces the bloods ability to clot. It can lead to excessive bleeding and blood transfusions

Plasma

A yellowish liquid made up of mostly water (90%) and helps transport blood cells, dissolved wastes (carbon dioxide, urea), nutrients (glucose, amino acids, minerals, oxygen), Proteins (fibringoen)