Circulatory System Flashcards
open transport system
blood bathes the cells directly (not contained in blood vessels)
closed transport system
blood is pumped around the body within a network of vessels
large vessels collect blood for pumping, smaller vessels distribute blood throughout the body and tiny capillaries provide the surface for exchange of materials
types of closed transport systems
annelids, fish, amphibians, birds and mammals
annelids
simplest closed system
two main blood vessels are connected by a series of five pairs of heart-like pumps called aortic arches
fish
heart has two main chambers and two lesser cavities organized in a row
blood flows through the heart > gills > body > heart
only flows through the heart once (single circulation)
amphibians
three-chambered heart
blood is pumped from heart > lungs > heart > body
having a single ventricle causes oxygenated and deoxygenated blood to mix
called incomplete, double circulation
birds and mammals
need a very efficient heart to support the high metabolic rate, constant body temperature, and high level of activity
four chambered heart
oxygenate and deoxygenated blood are kept separate
blood pressure is maximized to force blood through the capillaries quickly
blood flows from heart > lungs > heart > body
called complete, double circulation
three subdivisions of the circulatory system
systemic, pulmonary, cardiac
systemic
path taken by blood as it flows from the heart to the rest of the body and back (all cells except heart and lungs)
pulmonary
path of blood from heart to lungs and back
cardiac
route taken by blood within the heart
three main elements of circulatory system
transport vessels (arteries, veins, capillaries), transport medium (blood), pumping mechanism (heart)
three layers of artery
outer layer (connective tissue), middle layer (thickest, elastic fibres and smooth muscle), inner layer (single cell thick, consists of smooth epithelial cells)
blood consists of two elements:
plasma and cells
plasma
where blood cells are suspended
55%
straw colored fluid (92% water)
contains:
i) dissolved inorganic ions
ii) vitamins, minerals, hormones, organic nutrients
iii) protein moleculesred blood cells
erythrocytes 44% specialized for oxygen transport biconcave disk shape, no nucleus hemoglobin
white blood cells
leucocytes 1% numbers increase when you are fighting infection protect body from disease-causing agents have nuclei and appear colourless
types of white blood cells
macrophages - can pass through the walls of capillaries to engulf and digest pathogens
lymphocytes - allows the body to recognize and fight off pathogens; play a role in the formation of antibodies
platelets
fragments of cells when larger cells in bone marrow broke apart (are NOT cells)
no nucleus
break down quickly in blood
important in blood clotting
factors that cause vasodilation/vasoconstriction
regulate blood pressure, increase in activity and metabolic requirements, helps body conserve or eliminate heart
alcohol and nicotine promote vasodilation
pericardium
sac that covers heart
contains fluid that reduces friction as the heart beats
septum
muscular wall the prevents the mixing of blood from the two sides of the heart
atrium
thin walled chamber that pumps blood to the ventricles
ventricle
thick walled chamber that pumps blood to the body
atrioventricular valves
separate the atria from the ventricles
tricuspid
separates the right atrium from the right ventricle
has 3 flaps of tissue
bicuspid
separates the left atrium from the left ventricle
has 2 flaps of tissue
semi-lunar valves
valves between the ventricles and the arteries (aortic and pulmonary)
chordae tendinae
strong fibrous chords on the AV node
prevent the AV valves from inverting into the atria when the ventricles contract
arteriosclerosis
general term for several conditions in which the walls of arteries thicken and lose their elasticity
angioplasty
a surgical procedure used to open up a clogged artery
coronary bypass
a surgical procedure in which blood flow is re-routed around blocked arteries
aneurysm
a bulge in an artery or heart chamber caused by a weakened area of the heart muscle or arterial wall
arrhythmia
an irregularity in the speed or rhythm of the heartbeat
pacemaker
a device that sends electrical impulses that control the rate of the heartbeat
congenital heart deflect
a heart deflect that is present from birth
ischemic stroke
a stroke caused by a clot in a blood vessel, blocking blood flow to the brain
hemorrhagic stroke
a stroke caused by the bursting of a blood vessel in the brain, which causes blood to leak into the surrounding brain tissue
hemophilia
an inherited disorder in which the blood does not clot normally
leukemia
cancer of the white blood cells
xenotranspant
a transplant of tissues and organs from one species to another
nanotechnology
technology that uses microscopic structures on the scale of molecules
sinoatrial (SA) node
the modified heart cells in the right atrium that spontaneously generate the rhythmic signals that cause the atria to contract
atrioventricular (AV) node
the specialized heart cells near the junction of the atria and ventricles that cause the ventricles to contract
electrocardiogram (ECG)
a record of the electrical impulses generated by a beating heart
blood pressure
the force that blood exerts against the walls of blood vessels
systolic pressure
the pressure generated in the circulatory system when the ventricles contract and push blood from the heart
diastolic pressure
the pressure generated in the circulatory system when then ventricles fill with blood
sphygmomanometer
medical device used to measure blood pressure
Arteries
Carry blood away from the heart at high pressure
Veins
Carry blood towards the heart at a lower pressure
Contain one way valves
circulatory system functions
delivering nutrients and oxygen to cells
removing waste products of cellular processes
serving as a pathway from one part of the body to another for disease-fighting agents, hormones, and other chemical messengers
controlling body temperature in warm-blooded animals
lub-dub sound
lub - closing of atrioventricular (AV) valves as blood is pumped to the ventricles
dub - closing of semilunar valves as blood is pumped from the ventricles into the arteries
