CH 32: Circulatory system UCONN

circulatory system in which the fluid (blood) leaves blood vessels. It flows through tissues and then flows back into the circulatory system (sucking forces developed by heart) to be pumped out again Ex: arthropods and most mollusks

circulatory system in which the fluid (blood) always remains within blood vessels Ex: vertebrates

closed has more advantages because it can support higher levels of metabolic activity (need to circulate O2 rapidly- cannot tolerate long interruptions)

blood's liquid portion where blood's cells + other particles are suspended in

ions

portion of the circ. system in which blood vessels carry blood to and from breathing organs (lungs)

portion of the circ. system in which blood vessels carry blood to and from the systemic tissues

-SA node- The sinoatrial node located on the right atrial wall has pacemaker cells that send an electrical pulse that ensures that all atria cells depolarize (followed by contraction)

-AV node- atrioventricular node near the junction of the right atrium and right ventricle relays the depolarization to a conducting system depolarization spreads to both ventricles (followed by contraction)

-artery (fastest) large diameter; high pressure (thick walls of elastic fibers and smooth muscles); able to quickly supply the systemic cells with O2
-capillaries (slowest) smaller diameter; thin and delicate; have huge total cross-sectional area, which allows for gas exchange

-plasma- carries and transport blood's cells, nutrients, ions, waste products, hormones and clotting proteins
-RBC's- cells that contain hemoglobin, which bind to oxygen from the lungs and carries to the rest of the body and returns CO2 from the body to the lungs. Formed in red bone marrow and have short life span
-WBC's- cells that are part of the immune system, protect the body against pathogens
-Platelets- are pinched-off fragments of cells which are involved in blood clotting

Because the electrical depolarization initiated by the SA node (responsible for atria depolarization/ contraction) reaches the AV node (responsible for ventricles depolarization/contraction) after a short delay, ensuring that the atria depolarizes/ contracts before the ventricles.

section that ventricles pump blood through to get to systemic tissues

carry blood away from the heart; must have thick walls of elastic fibers and smooth muscles

diameter determines rate of blood flow; in different parts of the body can be dilated or constricted; during exercise, the muscles can be dilated to increase blood flow and O2 supply

heart chamber; Right receive deoxygenated blood and Left recieve oxygenated blood

extent to which the pressure on the blood exceeds the pressure in the environment of the animal (normal for humans 120/80)

add O2 to the blood and take up CO2 from the blood

consist only of vascular endothelium

cycle of contraction and relaxation of the heart

Muscular pump—the heart Fluid—blood Series of conduits—blood vessels

AV node relays the depolarization to a system of modified muscle cells; Depolarization spreads rapidly and the muscles contract

arteries, capillaries, and veins in the myocardium
is necessary for high-performance hearts, to provide O2 to all the muscle cells.

when a pigment releases O2

when ventricles relax

uses electrodes to record voltage changes during the cardiac cycle

is a respiratory pigment found in mollusks and arthropods; contains copper instead if iron and occurs in the blood plasma, not in cells

is the most common respiratory pigment and has evolved independently several times

the muscle tissue of a heart; must receive O2

when a pigment combines with O2

blood flow through tissue or organ

hemoglobin and hemocyanin

all tissues and organs other than the breathing organs; take up O2 from the blood and add CO2 to the blood

when ventricles contract

main chamber in the heart; R and L passes blood to either the pulmonary or systemic circuit

carry blood towards the heart