cardiovascular system

cardiovascular system

a closed circulatory system

cardiovascular system includes

heart, blood vessels, and blood

cadiovascualry system functions

transports gas, nutrients, and waste throughout the body, prevents loss of blood via ruptured vessels, fights invasion from foreign pathogens

Heart

fist sized, cone shaped muscular organ, a double pump because of two circuits

the heart has

four chambers and one way valves

pericardial cavity

location of the heart, in the anterior portion between the lungs

mediastinum

the space between the lungs, contains the heart

pleural cavities

two spaces, each holding a lung

pericardium

a tough, thick sac holding the heart, protects and anchors the heart to the diaphragm

pericardium layers

covered with a smooth layer of endothelium, fluid between the layers to reduce friction

myocardium

the bulk of the heart, composed of cardiac muscle and contracts, highly branched and attached with collagen connective tissue fibers

endocardium

a white sheet of endothelium, is continuous with blood vessel linings

septum

separates the heart into left and right chamber sets

fossa ovalis

a shallow depression separating the atria, marks an opening on babies in womb for blood flow, but closes during birth

atria

the two upper receiving chambers, smaller and not as muscular

ventricles

the two lower pumping chambers

pulmonary valve

controls the flow leaving the right ventricle to the pulmonary trunk, pumps into the pulmonary arteries to the lungs

aortic valve

controls the flow of blood out of the left ventricle into the aorta, stronger than the pulmonary valve due to increased blood pressure

mitral valve

(bicuspid) controls the flow of blood from the left atrium to the left ventricle

tricuspid valve

controls the flow of blood from the right atrium to the right ventricle

arteries

carry blood away from the heart, have pulses, elastic, thick walled vessels that can expand and contract

arterioles

small arteries that are constricted and dilated by muscles, contraction increases blood pressure, relaxation decreases blood pressure

peripheral resistance

varying blood pressure, commonly caused by arterioles

veins

carry blood back to the heart, thinner walled vessels under minimal pressure, no pulse

veins valves

internal valves that open toward the heart and close at the end of a heartbeat

veins stretch

has compliance, stretch with little recoil, leading to the largest amount of blood

lumen

the opening in the center of a vessel

tunica externa

most superficial layer of a vessel, anchors the vessel to surrounding structures

tunica media

middle muscular layer of a vessel,

tunica media layers

an external elastic membrane, smooth muscle, and internal elastic membrane

tunica intima

inner layer of a vessel

tunica intimate layers

subendothelial tissue and endothelium

capillaries

exchange materials with tissues, very narrow from branching of the arterioles, slow even flow to allow for oxygen and waste diffusion

capillary beds

interconnected capillaries to exchange materials with cells

venules

small veins that collect blood from the capillary beds, many join to form a vein that returns blood to the heart

left coronary artery

runs towards the left side of the heart

left coronary artery splitting

anterior interventricular branch and the circumflex branch

anterior interventricular branch

supplies blood to both ventricles

circumflex branch

supplies the left atrium and left ventricle

right coronary artery

runs towards the right side of the heart, supply the right atrium and right ventricle

right coronary artery splitting

posterior interventricular artery and the marginal artery

aortic arch

turns posteriorly to become the descending aorta

thoracic aorta

in the thoracic cavity above the diaphragm

abdominal aorta

the descending aorta after the diaphragm

inferior vena cava

returns deoxygenated blood from the lower body to the right atrium

superior vena cava

returns deoxygenated blood from the upper body to the right atrium

brachiocephalic trunk

first branch off the aortic arch, supplies blood to the right arm and neck

circle of Willis

AKA cerebral arterial circle, provides an alternative circulation if an artery gets blocked

blood

classified as a connective tissue

plasma

the liquid portion, buffers the pH of the blood near 7.4, transports large organic molecules in blood, and clots

plasma and pressure

maintains the bloods osmotic pressure due to protein presence

osmotic pressure

the net pressure in the blood that moves fluid from the tissues into the circulatory system

hydrostatic pressure

pushes fluid into the tissues by the pressure of the blood pumping from the heart

formed elements

the cell portion of blood, consists of red blood cells, white blood cells, and platelets

Serum

identical to plasma, but with the clotting proteins removed, centrifuged after clotting

red blood cells

small biconcave disks that carry oxygen, most abundant cell, contains about 250 million hemoglobin molecules

red blood cell manufacturing

continuously in red bone marrow of the skull, ribs, vertebrae, and long bone ends

red blood cell life

mature red blood cells are anucleate when released, have a lifespan of 120 days then are destroyed in the liver and spleen

hemoglobin

contains iron to combine loosely with oxygen to help carry oxygen, is recycled when red blood cells are destroyed

white blood cells

AKA leukocytes, larger with a larger nucleus, and lack hemoglobin, destroy foreign materials at injury sites

pus

contains many dead white blood cells that have fought the infection

granulocytes

have granules in the cytoplasm, include neutrophils, eosinophils, and basophils

agranulocytes

do not have granules in the cytoplasm

lymphocytes

include T

blood platelets

involved in coagulation (blood clotting) to stop bleeding, fragments of megakaryocytes

megakaryocyte

large bone marrow predecessor

coagulation cascade

a series of events to start the blood clotting mechanism, when platelets release chemicals

prothrombin activator

converts prothrombin to thrombin, released by platelets and injured tissues

fibrinogen

a protein manufactured by the liver that freely floats in the blood, converted to fibrin by thrombin

fibrin

winds around the platelet plug to provide the framework for the clot

diastolic pressure

pressure in the arteries during ventricular diastole

sphygmomanometer

medical equipment that measures blood pressure, the amount of pressure required to stop the flow of blood through the brachial artery

heart rate

regulated by the nervous system and endocrine system

SA node

(sinoatrial node) small mass of cardiac muscle in the right atrium, controls the cardiac cycle and spreads impulses to the atria

AV node

(atrioventricular node) where the impulse travels after the atria

Bundle of His

receives the impulse from the AV node, then sends it to the ventricular apex

Purkinje fibers

receives the impulse from the ventricular apex and causes the left and right ventricles to contract

Electrocardiogram

EKG/ECG, measures the electrical impulses in the heart

P wave

Atrial depolarization and atrial systole

QRS complex

Ventricular depolarization and ventricular systole

T wave

Ventricular repolarization and ventricular diastole

Syncope

fainting as a result of a lack of blood flow to the brain from a drop in arterial blood pressure

edema

a buildup of fluid in the body, can be caused by heart failure