Bio 1215- Chapter 14
Card Set Information
Bio 1215- Chapter 14
circulation gas exchange
circulation and gas exchange
exchange surfaces must be _____ for gas exchange.
_____________ --->better diffusion
more surface area
how do small animals and complex animals exchange gas?
body surface for gas exchange
: need a
transport system to minimize diffusion distance
what are 3 transport systems used by complex animals to minimize diffusion distance?
open circulatory systems
closed circulatory systems
how does the gastrovascular cavity minimize diffusion distance for complex animals? (2)
exposes more cells to the "outside"
may be multi-branched
allows for more surface area= better diffusion
briefly describe the open circulatory system. Give an example of some organisms.
(instead of blood)
leaves vessel and enters open areas called
arthropods and most molluscs
describe close circulatory systems. what are some organisms with open circulatory systems.
blood confined to vessels
annelids, cephalopods, vertebrates
what are the 2 chambers in the heart called and what are their functions?
1,2 atria (receive blood)
1,2 ventricles (pumps the blood to lungs and rest of body)
where does blood go after entering the atria?
--> ventricles --> arteries--> arterioles-->capillaries-->venules--> veins--> atria
describe the circulatory system of fish. (2)
heart has 1 atrium, 1 ventricle
describe the circulatory system of amphibians. (3)
2 atria, 1 ventricle
oxygenated and deoxygenated blood mix in ventricle
describe the circulatory system of reptiles.
3 chambers but have partial septum
(less mixing of oxygenated and deoxygenated blood)
describe the circulatory system of mammals or birds. (2)
2 atria; 2 ventricles
separate pulmonary and systemic circulations
what are the walls of the heart made of and how are the cells connected?
walls mostly of cardiac muscle
cells connected by gap junctions into 2 networks; atrial and ventricular
how do the heart chambers in the heart contract?
both atria contract at once, then both ventricles
what are the 2 types of valves in the heart and what are their functions?
2 atrioventricular valves prevent backflow into atria
2 semilunar valves prevent backflow into ventricles
define the cardiac cycle.
sequence of events around one heart beat
in humans, what is the average beats/min at rest?
in smaller animals, the heart rate is ______.
compare systole and diastole.
what is the pacemaker of the heart and where is it located?
sinoatrial (SA) node
in wall of right atrium
describe the routes of the electrical signals of the heart and how the heart contracts.
contraction begins at
wave of contraction spreads through atria
blood pumped to ventricles
atrioventricular (AV node)
travels to heart apex along
spreads upwards through the ventricles along
ventricular contraction pushes blood up towards lungs and aorta
heart rate and stroke volume regulated by what 2 systems?
nervous system and endocrine system
what are the 3 layers in artery and vein walls?
between artery and vein, which is thicker and why?
artery walls thicker due to more smooth muscle
what layers do capillaries have and why?
minimizes diffusion distance
blood moves mostly due to what?
pressure created by heart
pressure decreases to ______ in veins.
what are 2 ways that blood pressure is adjusted?
changing vessels diameters and blood volumes
why does blood pressure decrease farther from the heart?
blood pressure slows down because
total diameter of all the vessels increases
If venous pressure is zero, why does the blood return to the heart? (3)
valves ensure one way flow
veins squeezed by skeletal muscles
pressure changes in the thorax during breathing
what is the function of the capillaries?
exchange of fluids, gases, nutrients and wastes between blood and interstitial fluid (and then body cells)
local control of blood flow to capillaries is via __________________.
sphincters around arterioles
exchange at capillaries is due to what 3 things?
define bulk flow.
at upstream end, fluid pushed out of capillaries by blood pressure
(big solutes stay in vessels)
at downstream end, most fluid returns due to osmotic pressure
what is the function of lymphatic system, where is lymph returned?
collects "leftover" interstitial fluid
returned to venous blood flow near collar bones
what is leftover interstitial fluid called?
where do viruses and bacteria attack?
what is the pH of blood?
describe the components of blood.
made of connective tissue
cells (dead and living) =formed elements, in a liquid matrix= plasma
what is plasma mostly made of and what are its components?
=dissolved inorganic ions
= buffers, clotting factors, lipid-transporters
+gases, nutrients, wastes, hormones
what are electrolytes?
dissolved inorganic ions
what are plasma proteins?
buffers, clotting factors, lipid-transporters
what do electrolytes, plasma proteins, gases, nutrients, wastes, hormones help with?
help maintain osmotic balance with interstitial fluid
what are the 2 components of formed elements in blood?
red blood cells
white blood cells
what is the function of erythrocytes and how is this process done?
transport some oxygen and some carbon dioxide
oxygen binds to hemoglobin
where are erythrocytes produced and what makes them "dead" cells?
produced in red bone marrow
lose nucleus and last only 3-4 months
what is a characteristic about leukocyte and where is it produced?
when functional, their
true living cells
produced in bone marrow
what is the function of leukocytes?
immune and defensive functions
what happens to leukocytes during infections?
leukocytes number increases
what are the 4 specific types of functions for leukocytes?
antibodies, histamine, phagocytosis, cell killers
what are platelets and what are its functions?
cell "pieces" (not alive)
involved in clotting
forms a mesh that traps formed elements
What are the 3 steps in clotting?
cascade of reactions
fibrinogen (water soluble)
what are some characteristics for a great respiratory surface for gas exchange? (4)
large surface area
rich blood supply
what are the 3 structure for gas exchange?
define gills. (2) which way does they blood flow in gills?
outward extensions of body surface for gas exchange
often sheltered,may be ventilated
(for water to pass though)
to the water
what is a trachea? (2) which organisms use this for gas exchange?
air tubes leading inwards from surface holes (spiracles)
tubes come into contact with almost all cells
what is a lung and what is its function?
vascularized invaginations of body surfaces
circulatory system transports gases between the lungs and the body's cells
In the mammalian respiratory system, how is are freshened and how is it controlled?
air freshened by ventilation
controlled by nervous system by monitoring pH
Describe the respiratory system of a bird. where does gas exchange take place?
one way air flow through lungs; via bellow-like air sacs
gas exchange at
where is oxygen found in the blood?
99% attached to heme of hemoglobin, 1% dissolved in plasma
what are 2 characteristics of oxygen in blood?
not very soluble in water
most bound to respiratory pigments
what are 3 characteristics about carbon dioxide?
7% dissolved directly in plasma
23% bound to globin of hemoglobin
70% in the form of dissolved bicarbonate ions
arthropods and molluscs use _____________ to transport gases in blood.
hemocyanin (dissolved in the plasma)
Vertebrates use _______________ to transport gases in blood.
what are the 4 adaptations diving mammals have for gas exchange?
greater blood volume
high myoglobin levels
: shunts blood to vital organs
___________ stores oxygen in muscle cells.