Chapter 42

cellular; unicellular; external environment

1) a body size/shape that keeps cells in direct contact w/ environment (sponges, cnidarians, flatworms) or 2) circulatory system that moves fluid between cell's immediate surroundings (found in all other animals)

circulatory fluid (hemolymph) also serves as the interstitial fluid and bathes the organs directly; arthropods and mollusks; lower hydrostatic pressure = less costly

blood is confined to vessels and is distinct from interstitial fluid; annelids, cephalopods, and vertebrates; benefit = high blood pressure (effective delivery of O₂ & nutrients

carry blood from the heart TOWARD the capillaries

return blood to the heart FROM capillaries; except the portal vein, which carries blood between pairs of capillary beds

muscular chamber of the heart that RECEIVES blood

muscular chamber of the heart that pumps out blood

a heart with TWO chambers each of which the blood only passes through once; foudn in bony fishes, rays, sharks; swimming helps accelerate pace of circulation

pumps for 2 distinct circuts serve different tissues but combined in the heart; found in amphibians, reptiles, mammals

the right side of the heart carries oxygen-depleted blood away from the heart, to the capillary beds in the lungs ONLY, and returns oxygenated blood back to the heart

found in amphibians, where deoxygenated blood is carried to the capillary beds in both the lungs AND skin

contraction of the left side of the heart carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart

one complete sequence of pumping and filling; contraction = systole, relaxtion = diastole

the volume of blood each ventricle pumps per minute; determined by heart rate (number of beats per minute) and stroke volume (amount of blood pumped by a ventricle in a single contraction)

SLOWS; there are MANY capillaries, therefore the overall area of campillary beds is much greater than anywhere else in the circulatory system

a peptide that induces vasoconstriction

across endothelial walls of capillaries

drives fluid out of capillaries

create osmotic pressure differences between inside the capillary and the outside interstitial fluid; tends to pull fluid back into the capillaries

swelling resulting from the excessive accumulation of fluid in tissues

organs along a lymph vessel that filter the lymph and house cells that attack viruses/bacteria; play important role in body's defenses

the pressure exerted by a particular gas in a mixture of gasses; P_o2 = 160 mm Hg (partial pressure of O₂; is much less at sea level)

air sacs clustered at the tips of the tiniest bronchioles; where GAS EXCHANGE occurs; maximum partial pressure of oxygen is a always LESS in the alveoli than in the atmosphere

specialized secretions (containing a mixture of phospholipids and proteins) that relieve the surgace tension in the fluid that coats the surface of the alveoli; in their absence alveoli collapse

volume of air inhaled and exhaled with each breath; during maximum in/exhalation it's called the vital capacity, and amounts to about 3.4-4.8 L

networks of neurons that control breathing, located in the medulla oblongata [establish breathing rhythm] and pons [regulate medulla onlongata's tempo] (brainstem)

molecule consisting of a protein and metal (metalloproteins)that binds to O₂ and transport the majority of oxygen by circulating with blood (hemolymph) and are often contained within specialized cells; reduces cardiac output

vertebrate respiratory pigment that consists of 4 polypeptide chains that each contain a cofactor called a heme group with an iron atom at its center; e/a iron atom binds to 1 molecule of O₂, meaning 1 hemoglobin carries 4 O₂'s

when low pH decreases hemoglobins affinity for O₂; thus when CO₂ production is greatest, hemoglobin releases MORE O₂ which can be used to support cellular respiration