chapter 30 the circulatory system Flashcards
a network of vessels that contain the blood, and a heart
the circulatory system
the pump that keeps the blood moving through blood vesels
the heart
open circulatory system
fluid is pumped through short vessels that lead to open spaces in the body cavity
closed circulatory system
blood remains within vessels that exchange materials with the fluid surrounding the body’s cells
what area of the heart does blood enter?
the atrium
what area of the heart does blood exit?
the ventricle
pulmonary circulation
blood absorbs oxygen and releases carbon dioxide
systemic circulation
blood circulates throughout the rest of the body to unload oxygen and pick up carbon dioxide before returning to the heart
how are closed circulatory systems distinguished?
based on heart chambers
fishes and amphibians (larval) have how many chambers in their hearts?
2
amphibians (nonavian) and reptiles have how many chambers in their hearts?
3
birds and mammals have how many chambers in their hearts?
4
blood is a [blank] tissue that consists of…
a connective tissue consisting of cells and cell fragments (platelets) suspended in plasma
plasma
a liquid extracellular matrix
plasma is made of mostly…
water
what does plasma contain
water, antibodies, and dissolved substances
what does plasma carry?
red blood cells, white blood cells, and platelets
[blank] carries oxygen to body tissues
red blood cells
hemoglobin
found in red blood cells
a protein that binds to oxygen at respiratory surfaces and “unloads” oxygen at body tissues
what does a person’s blood type depend on?
what carbohydrates are on the surface of their red blood cells
agglutination
the immune system reacts to blood cells with foreign blood clumps together in this reaction
white blood cells
part of the immune system
provoke inflammation and destroy microbes, among many other functions
platelets
cell fragments that initiate blood clotting
how does clotting work?
platelets adhere to each other at a break in a blood vessel. Clotting factors reinforce the clot
functions of blood
gas exchange, nutrient transport, waste transport, hormone transport, formation of interstitial fluid, maintenance of homeostasis, and protection
[blank] carries blood away from the heart
arteries
arteries branch into smaller [blank]
arterioles
capillaries
the tiniest blood vessels
water and dissolved substances diffuse between each capillary and the interstitial fluid
what surrounds body cells?
interstitial fluid
capillaries flow into slightly larger [blank], which combine into [blank]
venules
veins
[blank] carries blood back to the heart
veins
how much blood does the heart pump in a day?
thousands of liters
myocardium
a thick layer of cardiac muscle that makes up most of the wall of the heart
pericardium
a sac that surrounds the heart that anchors the heart but also allows it to beat without being obstructed
atria
receives blood from veins
ventricle
pump blood into arteries
does the left and right side of the heart have different functions?
yes
what does to right half of the heart do?
receives blood from the body and pumps it to the lungs
what does the left half of the heart do?
receives blood from the lungs and pumps it to the rest of the body
the right atrium receives [blank] and pumps it to [blank] which then pumps it to the [blank]
oxygen-depleted blood
the right ventricle
lungs
blood travels through [blank] to the lungs
pulmonary arteries
blood picks up oxygen at the lung capillaries and returns to the heart through [blank]
pulmonary veins
pulmonary veins dump blood into the [blank] of the heart
left atrium
the left atrium pumps oxygen-rich blood to the [blank] which then pumps it through the [blank], to the rest of the body
left ventricle
aorta
the largest artery
aorta
cardiac cycle
a single beat of the heart, including contraction of both atria and both ventricles
the signal to contract begins at the [blank], also called the [blank]
pacemaker
sinoatrial (SA) node
what does a signal from the pacemaker do?
it spreads along the sides of the heart and the two atria contract in unison
what happens after the signal from the pacemaker
after a brief delay-giving time for the ventricles to fill with blood- the signal reaches the atrioventricular (AV) node
what does the atrioventricular (AV) node do?
sends the signal to contract through the ventricle walls
what contracts last?
the ventricles
they contract in unison
what completes the heart cycle?
the relaxation of the ventricles
physicians track the heartbeat with an [blank] which…
ECG
measures the electrical signals that pass through the heart walls from the pacemaker to the ventricles
the letters [blank] indicate different parts of a cardiac cycle
PQRST
what do the valves do?
the two sets of valves prevent blood from flowing backward through the heart
when the ventricles contract…
valves between the ventricles and atria slam shut
when the ventricles relax…
valves between the arteries and the ventricles slam shut
the familiar “lub-dub” sound of the heart comes from…
the two sets of heart valves closing
cardiac output
the amount of blood pumped each minute
determined by the heart rate and the strength of the heart
strong heart muscles pump [blank] blood with each stroke than weaker muscles
more
blood vessels form [blank] pathway
circulation
Arteries have a [blank] layer of [blank] muscle that can withstand [blank]
thick
smooth
high blood pressure
where vessels are only about as wide as a red blood cell
capillary beds
capillary walls are only [blank] cell layer thick, allowing…
one
water and substances to easily diffuse to body tissues
blood pressure in veins are…
low
do veins have a thicker or thinner layer of smooth muscle than arteries?
thinner
without much smooth muscle, veins [blank] when they are not filled with blood.
collapse
valves keep blood from…
flowing backward in veins
[blank] propels blood through open valves toward the heart
skeletal muscle contraction
what do doctors use to measure blood pressure?
a sphygmomanometer
systole
the higher blood pressure reading
reflects the pressure in arteries when the ventricles contract
diastole
the lower blood pressure reading
reflects the pressure in arteries when the ventricles relax
blood pressure [blank] during its path through the circulatory system
decreases
blood velocity is [blank] in the capillaries because…
lowest
the total cross-sectional area is high
a [blank] feedback system helps regulate blood pressure
negative
vasoconstriction
the narrowing of arterioles
blood pressure [blank] as the arterioles narrow
increases
vasodilation
causes blood pressure to drop
arterioles widen
lymphatic system
collects fluid that leaks from blood vessels; removes bacteria, debris, and cancer cells; and returns the liquid to the blood
lymph
the colorless fluid of the lymphatic system
lymph capillaries
absorb interstitial fluid and deliver it to larger lymph vessels
lymph nodes
remove foreign substances from lymph.
contains millions of lymphocytes
lymphocytes
white blood cells found in lymph nodes
function of lymphatic organs
produce, accumulate, or aid in the circulation of lymphocytes
what happens when the lymphatic system malfunctions?
excess fluid accumulates in body tissues.
