Biology 12 - Circulatory System Review

C6 - 3. Explain the roles of antigens and antibodies.

Antigens are foreign substances to a body that stimulate the release of antibodies. Antibodies are specialized proteins that attach to invading pathogens to neutralize them.

C6 - 2. List the major components of plasma.

Blood plasma is composed of water, plasma proteins, gases, nutrients, salts, wastes, vitamins, and hormones.

C5 - 5. Relate blood pressure and velocity to the total cross sectional area of the five types of blood vessels.

Blood pressure and velocity is highest in the arteries, dropping in the arterioles, dropping to a low of 10mm Hg in the capillaries, and then altogether lacking the pressure to reach the heart in the veins and venules. The blood in the veins and venules are moved along by minute contractions in skeletal muscle around the veins.

C4 - 5. Describe the measurement of blood pressure.

Blood pressure is measured by a sphygmomanometer. When the ventricles contract, systolic blood pressure is found by how far down a column of mercury is pushed down.

C5 - 6. Describe capillary-tissue fluid exchange.

Capillary-tissue fluid exchange occurs due to a pressure differential between blood pressure and osmotic pressure. Substances in the capillaries diffuse out on the arterial side, and substances diffuse in on the venule side.

C4 - 4. Describe hypertension and hypotension and their causes.

Hypertension is defined as consistently elevated blood pressure in the arteries. It can be caused by blockages in arteries. Hypotension is defined as low blood pressure in the arteries. It can be caused by miscommunication between the brain and the heart.

C5 - 7. Identify and describe differences in structure and circulation between fetal and adult systems, with reference to umbilical vein and arteries, oval opening, venous duct, and the arterial duct.

In a fetal circulatory system, the lungs do not provide oxygen. It instead obtains them from the placenta where nutrients, gases, and wastes are exchanged. Due to this unnecessary need for the pulmonary circuit, an opening between the right and left atria is created as a shortcut called the oval opening. An arterial duct located in the pulmonary artery also connects to the aorta to bypass the pulmonary circuit. The umbilical vein and arteries travel to and from the placenta. The venous duct connects to the umbilical vein in order to bring blood back to the baby's heart.

C5 - 3. Differentiate between pulmonary and systemic circulation with respect to oxygenation or deoxygenation of blood in the vessels involved.

In the pulmonary circuit, blood that travels away from the heart is deoxygenated, while blood that travels towards the heart is oxygenated. In the systemic circuit, blood that travels away from the heart is oxygenated while blood that travels towards the heart is deoxygenated.

C4 - 3. Differentiate between systolic and diastolic pressures.

Systolic pressure results from when the heart muscle contracts. It is the highest arterial pressure reached during ejection of the blood. Diastolic pressure, on the other hand, is the lowest arterial pressure during ventricular relaxation.

C7 - 1. Describe the functions of the lymphatic system.

The lymphatic system is a vascular system in the body that takes excess tissue fluid from the tissues and reinjects it into the bloodstream. As a whole, it fights infections, cleans lymph, produces lymphocytes, and leads to the production of antibodies. It also helps in absorption of fat from the intestine and transport to blood.

C4 - 2. Describe how the autonomic nervous system increases and decreases heart rate and blood pressure.

The medulla oblongata sends messages to the autonomic nervous system to control heart rate and blood pressure by stimulating sympathetic or parasympathetic nerve branches. They will speed up or slow down the heart, respectively.

C5 - 2. Describe and differentiate among the five types of blood vessels with reference to characteristics such as structure and thickness of vessel walls, presence of valves, and direction of the blood flow.

a) Arteries: thick, with elastic walls and surrounded by smooth muscle to control the diameter of the artery. They carry blood away from the heart. b) Arterioles: blood vessels that the arteries branch off into. They are about 0.2 mm in diameter or smaller, and are composed of mostly smooth muscle to allow for more control. They carry blood away from the heart. c) Capillaries: connected to arterioles and venules, they are very narrow and microscopic. Their walls are one cell layer thick and are the site of where gases and small molecules like glucose exchange to cells. d) Venules: blood vessels that join together to form a vein. They drain the blood from capillaries and form a vein. They carry blood towards the heart. e) Veins: blood vessels that are thinner than arterial walls, they have valves to prevent blood from flowing backwards. They act as blood reservoirs.

C3 - 1. Identify and give functions of the following: left/right atria, left/right ventricles, coronary arteries/veins, anterior/posterior vena cava, aorta, pulmonary arteries/veins, pulmonary trunk, atrioventricular valves, chordae tendineae, semi-lunar valves, and the septum.

a) Left/Right Atria: small chambers located on the top of the heart, they receive blood and contract to send blood through the tricuspid and bicuspid valves to the ventricles. b) Left/Right Ventricle: two large chambers on the bottom of the heart, they contract to pump blood far through the body. The right ventricle is smaller because it only needs to pump to the lungs. They force blood through semilunar valves to various places. c) Coronary Arteries/Veins: blood vessels that deliver oxygen and nutrients to the heart muscle itself and carry away waste. They branch off the aorta and empty into the right atrium. d) Anterior/Posterior Vena Cava: large veins in the body that collect all deoxygenated blood to send into the heart. The anterior one collects blood from the arms and head, while the posterior one collects blood from the rest of the body. e) Aorta: the largest artery in the body, it carries all blood away from the heart to various major body regions and organs from the left ventricle. f) Pulmonary Arteries/Veins: arteries and veins that make up the pulmonary circuit. The arteries carry deoxygenated blood away from the right ventricle to the lungs, and the veins carry oxygenated blood from the lungs to the left atrium. g) Pulmonary Trunk: a large artery connected to the right atrium that divides into pulmonary arteries. It carries deoxygenated blood to the lungs. h) Atrioventricular Valves: valves that are located between atria and ventricles, they prevent blood backflow and control the flow of blood between chambers of the heart. i) Chordae Tendineae: strong strands of fiber that support the atrioventricular valves and prevent them from inverting. j) Semi-Lunar Valves: valves that look like half moons that are located between the heart and an artery. They prevent blood backflow and control the volume of blood the travels through. k) Septum: heart muscle that separates the left and right ventricles of the heart.

C7 - 2. Identify and give the functions of the following: lymph capillaries, veins, and nodes.

a) Lymph Capillaries: these collect the cell fluids into lymph veins. b) Lymph Veins: these allow lymph to flow to either the right lymphatic duct or thoracic duct. c) Lymph Nodes: small oval structures that produce and store lymphocytes.

C6 - 1. Describe the shape, function, and origin of: red blood cells, white blood cells, and platelets.

a) Red Blood Cells: also known as erythrocytes, red blood cells are small, biconcave disks without nuclei. They are created in red bone marrow and transport oxygen, hydrogen ions, and carbon dioxide. b) White Blood Cells: larger than red blood cells, these cells have a nuclei and appear white. They fight infections and are created by both the red bone marrow and lymph nodes. c) Platelets: created by the fragmentation of large cells called megakaryocytes in red bone marrow. They are crucial in blood clotting.

C4 - 1. Describe the location and functions of the following: sinoatrial node, atrioventricular node, and the purkinje fibres.

a) Sinoatrial Node: located in the upper back wall of the right atrium, it initiates the heartbeat by sending out a signal to make the atria contract. It creates a consistent beat every 0.85 seconds. b) Atrioventricular Node: located in the base of the right atrium near the septum. It sends out a signal through AV bundles down the septum to purkinje fibres that spread through the ventricles. c) Purkinje Fibres: fibres used to stimulate cardiac muscle in the ventricles to cause the muscles to contract.

C5 - 1. Identify and give the function of each of the following: subclavian arteries/veins, jugular veins, carotid arteries, mesenteric arteries, anterior/posterior vena cava, pulmonary veins/arteries, hepatic vein, hepatic portal vein, renal arteries/veins, iliac arteries/veins, coronary arteries/veins, aorta.

a) Subclavian Arteries/Veins: arteries and veins that carry blood to and from the arms. b) Jugular Veins: veins that carry blood from the head to the anterior vena cava. c) Carotid Arteries: arteries that carry blood from the aorta to the head. d) Mesenteric Arteries: arteries that carry blood towards the intestines from the aorta. e) Anterior/Posterior Vena Cava: large veins that collect blood from all around the body to be redeposited into the right atrium to be reoxygenated. f) Pulmonary Veins/Arteries: parts of the pulmonary circuit that carry blood to and from the lungs and heart. g) Hepatic Vein: a vein that returns blood from the liver to the posterior vena cava. h) Hepatic Portal Vein: a vein that connects the blood vessels of the villi in the small intestine to the liver for processing. i) Renal Arteries: arteries that carry blood towards the kidneys. j) Iliac Arteries/Veins: arteries and veins that carry blood from the aorta to the legs back to the posterior vena cava. k) Coronary Arteries/Veins: arteries and veins that supply and support the muscles and cells of the heart itself. l) Aorta: the largest artery in the body, connected to the heart. It carries blood towards the major regions of the body and organs.

C5 - 4. Demonstrate a knowledge of the path of a blood cell from the aorta through the body and back to the left ventricle.

aorta -> body tissue -> superior/inferior vena cava -> right atrium -> tricuspid valve -> right ventricle -> pulmonary semilunar valve -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> bicuspid valve -> left ventricle -> aortic semilunar valve -> repeat