Cardiovascular System

Alison Bews and Emma Warshaw

Function

- Transports nutrients throughout the body

- Aids in the removal of wastes

Structure Affects Function- Arteries: Large blood vessels that carry oxygenated blood away from the heart to the

rest of the body. - separate into smaller arterioles that connect large arteries with capillaries

- Capillaries: several thin-walled blood vessels in which gas exchange occurs. - generally have gaps in between the cells of their thin cell walls to allow for

materials, such as white blood cells, hormone molecules and oxygen, to move into and out of the circulatory system.

- Blood flow is controlled by nerve-controlled sphincters. - Veins: carry unoxygenated blood passed from the cappilaries back to the heart to be re-oxygenated.

-They have valves that prevent backflow of blood-The rely on nearby muscle contractions to move the blood through the system.

Left (1): Representation of overall circulatory system

Right (2): Interaction of arteries, capillaries, and veins

Left (3): Muscle contractions and valve operationPicture Citations:

(1) http://mrkellysplace.weebly.com/uploads/6/5/2/9/6529063/437531741.gif?303

(2) http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect20.htm

(3) http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect20.htm

Diagram of Heart:

- Blood: an aqueous liquid that contains blood cells and platelets- Plasma: proteins, enzymes, nutrients, wastes, hormones, gases, and electrolytes- Red Blood Cells (RBCs): also called erythrocytes; determine a person’s blood type; ipick up oxygen from the lungs and deliver it to tissues; pick up carbon dioxide and unload it in the lungs- White Blood Cells: also called leukocytes; divided into granulocytes and agranulocytes- Platelets: small fragments of bone marrow cells that serve several functions from clotting blood to fighting bacteria to secreting vasoconstrictors

Composition of Blood:

- An RBC has a biconcave disc like structure

- Hemoglobin gives RBCs their red color and ability to carry oxygen

- Enzymes within the cell help produce enough ATP for hemoglobin to function without the need for a nucleus, mitochondria, or endoplasmic reticulum

Function and Structure of Erythrocytes

Hemoglobin (Emma)

- Basic Purpose:- Found in red blood cells- Molecule used to transport oxygen to the tissues through the arteries and capillaries- Used to transport CO2 back to the heart and lungs through veins to receive oxygen

again. - 1 completely saturated hemoglobin molecule can carry up to 4 oxygen molecules. - 2 kinds of hemoglobin: oxyhemoglobin (affinity for oxygen molecules) and

deoxyhemoglobin (affinity for CO2 molecules)- Oxyhemoglobin takes O2 from the lungs to body tissues, passes off the molecules to

myoglobin for use in cellular respiration, and then receives CO2 molecules to take back to the heart and lungs. The process then restarts.

-Structure:- Tertiary molecule composed of four globin molecules. - Each globin chain contains a heme molecule that contains iron.- Oxygen is attracted to the iron and binds with it to travel through the body. Picture Citation:

http://respiratorycasestudy-7.wikispaces.com/Hemoglobin

- Blood flows through open spaces called lacunae and sinuses

- Blood flows at a very slow velocity- Body cavity called haemocoel is filled with blood- Internal organs are bathed by blood- Long period of maturation- Materials are supplied and eliminated slowly- Materials are exchanged between the blood and

sinuses- Unregulated blood flow

Open Circulatory System

- Blood flows through closed veins - Blood flows at a very high velocity- No haemocoel - Internal organs are bathed not in blood- Blood takes a short time to mature- Materials are supplied and eliminated very rapidly- Materials are exchanged through capillaries- Regulated blood flow

Closed Circulatory System

Open v.s. Closed Circulatory System

Homeostasis (Emma)- Circulatory System and Homeostasis

- The continuous and controlled circulation of blood maintains overall homeostasis in the body.- It allows nutrients and molecules to pass to important tissues to keep them alive and working.

- Blood clotting and Regulation- To stop bleeding and keep body systems in working order, platelets clump at the puncture site

and releases a clotting factor called prethrombin that then converts to thrombrin. This also uses calcium.

- Thrombin then finds two amino acid chains that bind to form fibrin that winds around platelets to strengthen the block.

- This structure stays intact until blood vessel repair begins- Blood Pressure and Homeostasis

- A measure of the amount of pressure required to stop the flow of blood through an artery.- 2 kinds: systolic (pressure during ventricular contractions), diastolic (pressure in the arteries

during ventricular relaxation).- A normal blood pressure means that blood is circulating at the rate it should, keeping the body

in shape.

Blood Clotting

Picture Citation:

http://www.womens-health-advice.com/assets/images/clot-formation.gif

- Short Term Response- Epinephrine

- Hormone secreted by the adrenal glands in times of stress: adrenaline

- Causes an increase in heart rate, muscles strength, blood pressure, and sugar metabolism in an emergency

- Long Term Responses- Angiotensin II

- Produced in the kidneys in response to a low blood pressure- It causes vasoconstriction to bring blood pressure back up

- Antidiuretic Hormone- Produced when blood plasma solute is too high- Makes the kidneys retain water to break down the solute, vasoconstriction

- Erythropoietin- Produced by the kidneys and released in response to low O2 or blood pressure - Increases red blood cell production to increase O2 concentration and blood pressure

- Atrial Natriuretic Hormone- Released by cardiac muscles in response to high blood pressure- Promotes the loss of salt and water in the kidneys as well as vasodilation to decrease blood

pressure.

Cardiovascular Hormones

Major Disorder (Emma)- Mitral valve prolapse and regurgitation

- Occurs when the mitral valve between the left atrium and left ventricle has a defect that causes it to not close entirely with heart contractions.

- This causes some backflow of blood since the valve flaps contract upward into the left atrium.

- This allows blood from left ventricle to be sucked back into the left atrium (regurgitation), thus causing less blood to pump through the aorta and go where it is needed.

- Symptoms- Also called click-murmur syndrome because a faint clicking can be heard with a

stethoscope in a normal examination. - Many people can have it and not ever be affected. It depends on the severity of the

prolapse.- Irregular heartbeat (arrhythmia) , dizziness, shortness of breath, fatigue, and chest

pain that is not related to a heart attack are common symptoms.- Risk Factors

-Symptoms are more common in men over fifty-It can run in families that have a history of muscular dystrophy or scoliosis

-Treatment-For small cases, a doctor may prescribe Beta blockers to control heart rhythms or blood thinners to prevent possible blood clots from the defect. -Valve repair or replacement may be used for more serious cases.

Mitral Valve Prolapse: Continued

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RSS. Web. 20 May 2015. - Mader, Sylvia S. "Circulation and Cardiovascular Systems." Biology. Tenth Edition ed. New York: McGraw

Hill, 2010. 603-607. Print.- "Major Differences." Difference between Open and Closed Circulatory System. Web. 20 May 2015. - "Mitral Valve Prolapse." Mayo Clinic. Mayo Clinic, 5 Apr. 2015. Web. 21 May 2015. <

http://www.mayoclinic.org/diseases-conditions/mitral-valv- Muller, Michael. "The Circulatory, Respiratory, and Digestive Systems." The Circulatory System. University

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Works Cited