A&P Circulatory System Test

What is the conduction system of the heart?

1) Electrical signal is generated in the SA node (the hearts pacemaker) 2) Transmitted to both atria by the interatrial bundle 3) Moves to the AV node on opposite side of right atrium 4) Slight delay before signal is sent down the bundle of His to the apex of the heart 5) From left and right bundle branches the impulse is sent up the purkinje fibers allowing the two ventricles to contract in unison.

List and Describe the four tissues that compose the heart.

1) Pericardial sac: thin fibrous double layered sac enclosing the heart. Contains fluid inside sac. 2) Epicardium: serous membrane of smooth outer surface of the heart. 3) Myocardium: middle layer composed of cardiac muscle cell responsible for heart contraction 4) Endocardium: smooth inner surface of heart chambers.

Explain the flow of blood through the heart beginning in the right atrium and ending in the flow of blood to the body.

1) Right atrium receives deoxygenated blood from the body through inferior and superior vena cava. 2) Blood flows from right atrium into right ventricle through tricuspid AV valve and atrium contracts to send the last bit. 3) Right ventricle fills with blood and contracts to send that blood through the pulmonary arteries to the lungs. (through pulmonary valve SL) 4) Blood flows from lungs to the left atrium through the pulmonary veins. 5) Left ventricle fills and the left atrium contracts to send the last bit (through the mitral bicuspid/left AV valve). 6) Left ventricle contracts and pumps blood to the aorta and the rest of the body (through aortic SL valve) 7) blood is brough back to the right atrium by vena cava.

Describe the major vessels of the heart: Superior and Inferior Vena Cava: Aorta: Pulmonary Arteries: Pulmonary Veins: Coronary Arteries:

1) superior and inferior vena cava: major vein that brings blood back to heart. 2) Aorta: major artery that takes blood to body 3) Pulmonary Arteries: take blood away from heart to lungs 4) Pulmonary Veins: bring blood to heart from lungs 5)Coronary Arteries: feed the heart muscle

What are blood vessels? Describe arteries: Describe Capillaries: Describe Venules:

A network of tubes Arteries: arterioles move away from the heart, made up of elastic fibers and circular smooth muscle Capillaries: where gas exchange takes place, one cell thick. Venules: Veins that move towards the heart. One way valves.

What is the structural difference between the AV and the SL valves? What is the composition difference between the AV And SL valves?

AV= POCKETS SL= HALF MOON The atrioventricular valves are thin structures that are composed of endocardium and connective tissue. The semilunar valves are flaps of endocardium and connective tissue reinforced by fibers which prevent the valves from turning inside out.

Where is the aortic arch? Where is the pulmonary arch?

Aortic: between left ventricle and aorta Pulmonary: between the right ventricle and pulmonary trunk.

Describe the apex and the base of the heart.

Apex: blunt rounded point of cone Base: flat part of opposite of end of cone.

What are the basic differences in construction and location of arteries and veins and capillaries.

Arteries have a smaller lumen with more smooth muscle. Veins have one way valves. Veins are closer to the surface and their anatomy is more irregular.

What is the difference between atrioventricular valves and semilunar valves?

Atrioventricular valves: between atria and ventricles. Semilunar valves: between ventricle and pulmonary trunk and ventricle and aortic arch

what is a cardiac cycle? Describe one

Cardiac cycle: one complete heartbeat or pumping cycle 1) Late Diastole/passive ventricular filling: both chambers relaxed, blood coming back to the atria, increases atrial pressure and forces the AV valves open. Ventricles filled passively. 2) Atrial Systole: contraction completes the emptying of blood from atria. AV valves are open. P wave of ECG. SA node has fired 3) Isovolumetric Ventricular Contraction: Ventricles begin to contract but volume remains the same. Pressure increases in side ventricles, semilunar valves still closed, AV valves snap closed (1st heart sound) 4) Ejection: Pressure inside ventricles increases and blood is pushed out. Semilunar valves open. 5) Isovolumetric Ventricular Relaxation: Ventricular diastole, semilunar valves close (2nd heart sound), AV valves still closed, pressure decreases, volume stays the same.

Describe Red Blood Cells

Erthyrocytes: have a double membrane layer, concave center, no nucleus or mitochondria, can't repair themselves, carry hemoglobin, and formed in the bone marrow.

What is the largest group of cells in the formed elements?

Erythrocytes

Describe in general terms the process of blood cell formation and destruction.

Formation: Erythropoises (blood production) happens in red bone marrow. Hematopoietic stem cells differentiate to form RBCs. The hormone erythropoietin regulates RBC production. Destruction: The blood cells live 120 days until it fragments into capillaries. Macrophages phagocytose the broken cells and send proteins, iron away for synthesis of new Hb.

What is the job of the heart valves? What are the valves between the heart chambers?

Heart valves prevent blood from back flowing. 1) Tricuspid: between right atrium and right ventricle. Made of 3 flaps of endocardium 2) Bicuspid/Mitral: between left atrium and left ventricle. 2 flaps of endocardium

Describe Hemoglobin. What happens when it binds oxygen? Where can it be found?

Hemoglobin is a pigment that gives blood its characteristic color. Made up of 4 protein chains with a heme group at the center of each. IT carries oxygen and it can bind 4 oxygen molecules. When it binds oxygen, the proteins change shape and color. It can be found in red blood cells.

What are venous sinuses?

Large venus structures with thin endothelial walls.

What is the flow of blood through the blood vessels in systemic circulation?

Left ventricle pumps blood through aorta to body organs and tissues. blood moves from arteries to arterioles to capillaries. Comes back through venues, veins, and superior and inferior vena cava.

What are the main cells in the immune response/defense of the body?

Leukocytes (white blood cells)

Describe white blood cells.

Leukocytes: have a nucleus, lack hemoglobin, and defend against disease and infection.

What are the terms given to each heart sound? What causes each sound?

Lubb or ventricular systole/contraction: is when blood rushes against the AV valves and snaps them closed. It is the turbulence in blood when the AV valves close. Dubb or ventricular diastole/relaxation: blood rushes back toward ventricles and snaps the semilunar valves closed. Turbulence in blood when semi-lunar valves close.

What are the the of cells that make up the myocardium? (describe their structure and properties)

Myocytes. They are branches with single nuclei and intercalates discs (gap junctions) between them. They are striated because of sarcomeres. They are myogenic (not regulated by nervous system).

Describe plasma and what it is composed of.

Plasma is the liquid portion of the blood. It contains clotting factor, hormones, antibodies, dissolved gases, nutrients, and wasted.

What are the two types of circulation? Define each.

Pulmonary Circulation: Blood to the lungs and back to the heart. Systemic Circulation: blood to the head, lower limbs, and upper limbs. Left ventricles pump blood through aorta to body organs and tissues. Blood moves from arteries to arterioles to capillaries. Comes back through venues, veins, and superior and inferior vena cava.

What are the three types of blood cells that compose the "formed elements" ?

Red Blood Cells/Erythrocytes: White Blood Cells/Leukocytes: Platelets/Thrombocytes:

Where are red blood cells found? What is their job?

Red blood cells found in the arteries, veins, ventricles, and the heart. Their job is to transport oxygen in the blood.

What is the overall job of the cardiovascular system? What are the three main things it is composed of?

The cardiovascular system is the transport system. IT carries 02 and nutrients to cells and C02 and waste away from cells. Heart: muscular pumping device Closed Vessels: arteries, veins, etc. Blood: that runs through those vessels

What is the size, location, and general purpose of the heart?

The heart is the size of a closed fist. It is located in the thoracic cavity in mediastinum. 2/3rds rests left of midline Purpose: generates blood pressure, routes blood (pulmonary and systemic), ensures one way blood flow, and regulates blood supply.

Describe platelets

Thrombocytes: small membrane bound cell fragments that contain enzymes and other substances important for clotting.

What are the components of whole blood and the percentages that they make up?

Whole blood is made up of blood cells (45%) and plasma (55%)

Contraction of the ventricles begins at the ____ and contracts _____ toward the ____ of the heart.

apex, upwards, base

What type of tissue is blood? What is its purpose?

blood is a fluid connective tissue Its purpose is to 1) transport dissolved gases, nutrients, hormones, and metabolic wastes. 2) regulate pH and ion composition of interstitial fluids throughout the body 3) blood clotting 4) defend against toxins and pathogens. 5) stabilize body temperature.

Ventricles are for ______ blood through arteries. Right ventricle pumps to the _____. Left ventricle pumps to ______.

pumping lungs body

The atria are for _____ blood from veins. The right atria receives blood from ______. Left atria receives blood from ______.

receiving body lungs

What are the four chambers of the heart? What are the three major veins? What are the two major arteries?

right atrium, right ventricle, left atrium, and left ventricle Veins: superior and inferior vena cava, pulmonary veins Arteries: pulmonary trunk and aorta

What is the function of thrombocytes?

stop bleeding by clumping and clotting blood vessel injuries. Prevents loss of body fluids.

What is the hepatic portal circulation?

veins that flow into the liver before returning to the heart.