Circulatory System

The circulatory system includes all of your vasculature (blood vessels) and the heart! It's where the heart contracts to pump blood around the body in a double loop system.

deoxygenated

oxygenated

The pulmonary loop brings blood to the lungs so that RBCs can complete gas exchange with alveoli. The systemic loop carries blood to the body tissues and then back to the heart.

This allows for the separation of oxygenated and deoxygenated blood and ensures that body tissues have a constant supply of oxygen for cellular respiration

when the atria and ventricles (cardiac muscle) is at rest.

when the atria and ventricles contract.

atrial systole occurs directly before ventricular systole.

atrioventicular valves (av valves)

atrioventicular valves

Maximizes the amount of blood in the ventricles during contraction (allows atria to empty into ventricles)

increase (because volume in the atria decreases)

it prevents backflow of blood (ensures that all blood is pumped from the ventricles to the pulmonary or systemic loops)

Increase (because the volume inside of the ventricles decreases)

To the pulmonary or systemic loops of the circulatory system (depending on right or left ventricle)

to prevent backflow of blood

the blood hitting the clsoed av valves makes the 1st heartbeat sound

the blood hitting the closed sl valves makes the 2nd heartbeat sound

contraction of the chambers. These pressure changes control the opening and closing of AV and SL valves in the heart.

higher

The circulatory system includes all of your vasculature (blood vessels) and the heart! It's where the heart contracts to pump blood around the body in a double loop system.

sl ; the pulmonary artery and aorta

volume decrease so pressure increase

+ the atria contract causing a rapid but relatively small pressure increase, which pumps blood from the atria to the ventricles, through the open atrioventricular valves
+ teh semilunar valves are closed and blood pressure in the arties gradually drops to it minimum as blood contrinues to flow along them but no more is pumped in.

the centricles contract with a rapid pressure build up that causes the atrioventricular valves to close

the semilunar valves remain closed

the pressure in the ventricles rises above the pressure in the artieries so the semilunar valves open and blood is pumped from the ventricles into the arteries, translently maximazing the arterial blood presure

pressure slowly rises in the atria as blood drains into them from the veins and they fill

the contraction of the ventricular muscles wanes and pressure inside the ventricles rapidly drops below the pressure in the artieries ,causing the semilunar valves to close

the atrioventricular valves remain closed

pressure in the ventricles drops below the pressure in the atria so the atrioventricular valves opens

blood from the veins drains into the atria and from there into the ventricles, causing a slow increase in pressure

lower

So that blood can be pumped through the pulmonary artery to the lungs and through the aorta to the body tissues and backflow will not occur

after the intial pump of blood into the artieries, pressure begins to decrease as it desperses

AV valves begin opening as the pressure in the ventricles drops below the pressure in the atria (which have been gradually filling with blood from the vena cava and pulmonary veins)

The heartbeat is actually controlled by a specialized group of cells in the right atrium called the sinoatrial (SA) node.

contraction that is controlled by muscle cells directly

the pacemaker

sets the pace for the beating of the heart

right atrium

1) sa node gernates impulse; atrial excilation begins
2) impulse delayed at av node
3) impulse passes to heart apex; ventricular excitation begins (goes through bundle branches)
4) ventricular excitation complete (goes thorugh purkinje fibers)

av node

middle of the four chambers

ventricular contraction (systole) will occur once the electrical impulse has spread down the septum towards the apex of the heart and around the ventricles by nerve fibers called purkinje fibers

yes

y shaped

Cardiac muscle cells are branched (Y-shaped) to connect to multiple fibers. They are connected by intercalated discs, where cytoplasm between the cells is connected for faster transmission of electrical impulses that control contraction.

special regions where the cytoplasm of one cells connects with the next for rapid transmission of the contraction signal

Energy! The mitochondria undergo cellular respiration to ensure energy supply for cardiac muscle contraction. Cellular respiration requires glucose, and glycogen is a polysaccharide of glucose molecules. If glucose concentration gets too low, glycogen can be broken down to ensure that cellular respiration can continue.

EKG

records the electrical signals from the heart through a series of electrodes.

atrial systole (contaction) due to sa node trigger

delay of av node allowing filling of ventricles

ventricular systole (contraction) due to purkije fibers

veginning of venetricular relaxation

ventricular diastole (relax

Ventricular contraction (QRS complex) requires more of an impulse to occur than atrial contraction (P-wave)

delviers a electrical shock to the sa node to reeestablish normal rhythm; used when there is a disruption in the heart's electrical activity such as ventricular fibrillation

fast and irreglar heartbet

Automated External Defibrillator

it can be used in first aid emergencies involving heart activity.

monitor electrical cardiac activity.

The right side of the heart naturally controls heart rate, so contraction of these cardiac muscle fibers will influence the left side to contract at the same time.

medulla

breathing rate and heart rate h

increase the amount of gas exchange occurring between alveoli and capillaries.

response to stress

An increase in heart beats -- pump more blood to complete more gas exchange in the lungs

decreases heart beats to decrease rpessure on arterial walls

release of epinephrine increases your heart rate

arteries, veins, and capilaries

The distinctions between these vessels have to do with the direction in which they carry blood.

thickest wall to withstand high blood pressures.

eins have wider lumens and valves to prevent backflow as they return blood to the heart.

Capillaries are thin and branched and have fenestrations (windows) to allow for efficient gas exchange with tissues.

away

toward

narrow

wide

high

lowest

low

thick

thin

thinnest

built for withstanding and maintaining high pressure; elasticity = ppulsing action

built to max blood flow in one direction, at low pressure, against gravity

built for exchange of materials

lumen diameter decreases

lumen diameter increases

the body is able to controls blood pressure and the amount of gas or nutrient exchange occurring in tissues by changing the rate at which blood travels around the body.

More blood can near the surface of the skin to dissipate body heat

makes it easier to echange materials

one cell layer thick, helps gas exhcnage occur more eddiviently

When the ventricles contract and blood is pumped through the arteries, the blood exerts a pressure on the artery walls.

high blood pressure for an extended duration of time).

measures two values -- the blood pressure during ventricular systole (contraction) and ventricular diastole (relaxation).

<120 (systolic) and <80 (diastolic)

pressure in the artieries when ventricles contract
normal == 120 mmHg

pressure in the arteries when ventricles relax
normal = 80 mmHg

During ventricular contraction a higher volume of blood is pumped into the arteries. When ventricles relax this volume of blood dissipates through the body and pressure decreases.

Smooth muscle and stretchy, elastic fibers (mostly the protein elastin) in the tunica media

More salt (solute) in the blood will result in more retention of water in the blood, thus increasing the blood volume

salt, obestiy
smoking
genetics
cholestrol
anger
stresss

When cholesterol, other lipids, or other cellular debris accumulate in an artery, they form a plaque. This restricts blood flow, and if it bursts it can form a blood clot.

Changes to diet and medication can help treat atherosclerosis.

a catch-all term for any disease or disorder that influences the structure and therefore function of the heart and its vasculature.

coronary artery disease

where atherosclerosis occurs in the coronary artery and restricts blood flow to heart tissue.

If the blockage in the coronary artery becomes complete or severely restricts blood flow to cardiac muscle, tissue death can result.

myocardial infarction

buildup of cholesterol

high ldl
chronic high blood glucose
hypertension
trans-unsaturated fats
strees
smoking

blockage

angina
myocardial infarction

heart pain