Ch 13: Circulation System

what is a hematocrit?

what is a hematocrit?

percent of blood volume that is composed of red blood cells

(^simple definition given in slides)

what is a hemoglobin?

the oxygen carrying component of blood.

(also carries CO2 away from the tissues)

What are three layers in a centrifuge blood sample?

put them in order top to bottom

blood plasma, buffy coat, formed elements

What is the "buffy coat" in a centrifuge blood sample?

buffy coat is composed of platelets and white blood cells

what is blood plasma?

the fluid portion of blood that consists of water,, ions, proteins, nutrients, hormones waste, etc.

what are white blood cells used for?

immunity

what are platelets and what are they used for?

cell fragments for blood clotting

typically, what do the red and blue vessels of the circulatory system signify?

• red: oxygenated blood (lungs -> body tissues) -blue: deoxygenated blood (tissues --> lungs)

define myocardium

the muscular tissue of the heart

t/f EACH cardiac muscle cell contracts with a heart beat.

true

define septum in terms of the heart

what separates the left and right side of the heart

are ventricles found in the upper or lower parts of the heart?

lower

ventricles pump blood to where?

into the arteries

t/f the left and right ventricle contract at different times.

False. the left and right ventricle contract at the same time

blood from the right ventricle goes to where?

right ventricle pumps deoxygenated blood to the lungs (via pulmonary arteries)

blood from the left ventricle goes to where?

left ventricle pumps oxygenated blood to the body tissues (via aorta)

define aorta

an artery that allows blood to go from the left ventricle to the rest of the systemic circulation

define interventricular septum

septum that separates two ventricle

the superior vena cava delivers blood from the ___ body to the heart

upper body

[think.. superior = upper]

the inferior vena cava delivers blood from the ___ body to the heart

lower body

[think.. inferior = below]

define atrium

upper chamber of the heart the receives venous blood

the right atrium receives blood from where?

from systemic circulation (via the venae cavae)

the left atrium receives blood from where?

Receives blood from the pulmonary circulation (via pulmonary veins)

what separates the atrium and ventricles?

connective tissue known as the fibrous skeleton

what gas do cells produce?

carbon dioxide (CO2)

blood from the left atrium enters the left ventricle through what valve?

the Bicuspid valve

after blood enters the lungs, what part of the heart does it go into?

left atrium

the left side of the heart always contains oxygenated blood]

blood leaves the left ventricle through what valve?

the aortic valve

blood from the right atrium enters the right ventricle through what valve?

through the tricuspid valve

blood leaves the right ventricle through what valve?

pulmonary valve

explain the pulmonary circulation pathway.

deoxygenated blood leaves the body tissues --> right atrium --> right ventricle --> into the lungs to become oxygenated

explain the systemic circulation

oxygenated blood from the lungs --> left atrium--> left ventricle --> into the body tissues to transfer oxygen

while hemoglobins transport oxygen throughout the body, what else do they pick up and where do they deliver it?

carbon dioxide that is delivered to the lungs

what are atrioventricular valves?

valves between the atria and ventricles.

name the three atrioventricular valves

1. Tricuspid valve

2. Bicuspid valves

explain the characteristics of the tricuspid valves

-three flaps -between right atrium and ventricle

explain the characteristics of the bicuspid valves

-two flaps -between left atrium and ventricle

how does pressure affect the AV valves?

valves will open and close due to pressure difference (ex. pressure can push a valve open or force it close)

what are muscles are valves made of and what do they do?

Papillary muscle // they limit movement to prevent back flow of blood

name the 2 semilunar valves

1. pulmonary valve 2.aortic valve

where is the pulmonary valve located?

between the right ventricle and pulmonary trunk

where is the aortic valve located?

between the left ventricle and aorta

which valves are larger, AV valves or Semilunar?

AV valves (because they have to handle the pressure between atrium and the ventricles)

t/f: AV valves close and open due to muscle contraction

false, they open because of pressure, not muscle contraction

t/f: the left and right atria contract at the same time

true [the same goes for ventricles]

what is it called when the ventricles contract at the same time?

systole contraction

define systole

the period of ventricular contraction and when blood ejects [point of highest pressure]

define diastole

the period of ventricular relaxation and blood filling [point of lowest pressure]

t/f: blood flows in a a direction of lower pressure to higher pressure

false, blood flows from high pressure to low pressure

t/f: blood leaves the left and right ventricles at different times

false: the blood leaves both ventricles at the same time

(since they contract at the same time, think of systole)

what are the two heart sounds?

Lub and Dub

describe the "lub"

-first heart sound -soft, low pitched -onset of systole -caused by AV valve closing

Describe the "dub"

-second sound

• louder than lub -caused by semilunar valve closing -onset of diastole

what is stroke volume?

amount of blood ejected

t/f: people who exercise have lower stroke volume

False, fit people have a higher stroke volume. [think.. fit people stroke more]

what is the relationship of atria-ventricle pressure in diastole.

when ventricle pressure falls below atrial pressure, that is when the AV valves open.

describe end-diastolic volume (EDV)

how much blood filled ventricles at the end of diastolic

t/f: volume and pressure are opposites

true, when pressure increases, volume decreases

what initiates depolarization in cardiac cells.

depolarization in sinoatrial (SA) node

what structure of the heart carries AP from the right atrium?

the AV node

how do APs travel to ventricles

via bundle of His [his = atrioventricular bundle]

what is an electrocardiogram (ECG/EKG)

detects electrical activity in the heart via electrodes

what are the 3 ECG waves? (in order pls)

-P wave -QRS waves -T waves

what causes the P wave?

atrial depolarization

what causes QRS wave?

depolarization of the ventricles

what causes T wave

results from REpolarization of ventricles

t/f: repolarization causes contraction

false, DEpolarization causes contraction

in which wave does the first heart sound occur

lub is in the QRS

where does the 2nd heart sound occur?

in the T wave

what is the function of blood vessels

distribute blood to tissues and regulate blood pressure

what are blood vessels made of?

connective tissue, smooth muscle and epithelial tissue

(p.s. only capillaries have epithelial tissues)

how does smooth muscle help blood vessels?

helps control dilation and constriction of blood vessels

what are arterioles and where are they found

branches of arteries // found between arteries and capillaries

describe a capillary

-smallest blood vessel -site of substance exchange between cells and vessels (ie. nutrient n waste)

the vessels between capillaries and veins are called what?

venues

describe the blood vessel pathway

artery --> aterioles --> capillaries --> venule --> veins

[goes in alphabetical order: a-a-c-v-v]

describe the characteristics of arteries

• are strong, thick (in order to withstand pressure since they are the closest to the heart) -made of elastic walls -have high pressure/low volume

describe the characteristics of veins

-weak walls -wider lumen (lumen = open space) -have low pressure but high volume -hold 54% of total blood volume

where does vasoconstriction and vasodilation occur?

in the arterioles in order to control the flow of blood in capillaries

what is the structure of capillaries and why is it important to it's function?

made of a single layer of epithelium to allow a rapid exchange of substances

how does blood pump into the heart from veins?

through skeletal muscle pump

what structure keeps veins flowing one way?

venous valves

what is the function of the coronary artery?

serves as the blood supply for the heart, thus nourishes it.

what is coronary artery disease?

Insufficient blood flow (ischemia) to the heart due to change in artery [causes heart attacks]

what is the main function of the lymphatic system?

-transports excess ISF that is filtered out of blood vessels back to the blood -transport fat absorbed from the small intestine into the blood -has lymphocytes to defend against disease -lymph nodes to remove pathogens in fluid before returning to blood