Lecture #29: Circulation In Animals I Flashcards
Why is diffusion insufficient over distances > than a few millimeters
because time to diffuse over a distance is the square of the distance
_________ makes sure no substance must diffuse far to enter or leave cell.
The circulatory system
What do cnidarians, who have body wall 1 or 2 cells thick,(jellyfish etc) use for digestion and diffusion?
Gastrovascular Cavity (has branches radiating to and from circular canal)
Planaria and flatworms also have gatrovascular cavities that_________
exchange materials with environment through single opening
What do the 2 types of circulatory systems have in common?
fluid (blood), tubes (blood vessels), muscular pump (heart)
Heart powers circulation by using ________ to elevate _________ which then flows down a _______ back to the heart.
metabolic power
blood pressure (or hydrostatic)
pressure gradient
Open circulatory System
_______ have OCS’s.
Organs bathed in ______ called ______ in insects
Heart pumps ________ into interconnected ______ surrounding the organs allowing exchange.
Insects, arthropods, and most mollusks
circulatory fluid
haemolymph(blood and intestine fluid)
Haemolymph
sinuses
Closed Circulatory Systems
_________ have them
Blood is confined to ______ and is distinct from _______.
Hearts pump blood into ________ that branch into _______ coursing through _____.
Materials exchanged by _____ between blood and intestine fluid.
earthworms, squid, octopus and vertebrates
vessels
intestinal fluid
large vessels
smaller ones
organs
diffusion
Closed system of vertebrates often called
cardiovascular system
heart consists of one _____ or two ______ (chambers that receive blood returning) and one or two _____ (chambers that pump blood).
atrium
atria
ventricles
3 main types of blood vessels
Arteries (carry blood away from heart to organs)
Veins (carry blood back)
Capillaries (form networks called capillary beds that inflate each tissue)
arteries branch into ______, small vessels that ________
aterioles
convey blood to capillaries
at downstream capillaries converge into ________ which then converge into ______ which return blood to heart.
venules
veins
A ______ heart has one atrium and on ventricle
Blood pumped from ventricle to _____ where it picks up _______ and disposes of ______.
Then converges into blood vessel that _______ to _____ that surround the organs (system circulation).
fish
gills
oxygen
carbon dioxide
carries blood
capillary beds
In fish blood goes through 2 ______.
When blood flows through bed ________ drops a lot.
Oxygen rich blood flows slowly, constrains _________ and limits _______
capillary beds
blood pressure
the delivery of oxygen to blood tissues
max aerobic metabolic rate
What has 3 chamber heart
frogs and amphibians
in 3 chamber heart, ventricle pumps blood into _______ and _______.
pulmo-cutaneous circulation
systemic circulation
in pulmo-cutaneous, blood picks up ____ and releases____ before returning to heart’s _____.
System circulation takes most of _______ and supplies all ______ and returns oxygen-poor blood to _______ via veins
o2
co2
left atrium
returning blood
body organs
right atrium
________ have 4 chambered heart which is divided into ________.
Crocs, birds, mammals
desperate right and left chambers
in 4 chamber hearts, left side pumps/ receives only _______ and right side handles only ________
double circulation _________ so systemic circuit and prevents_________.
oxygen rich
oxygen poor
restores pressure
mixing oxygen rich and poor blood
Endothermic use _______ more energy than ectotherms and there need more fuel and O2 and to remove more co2
ten times
The Mammalian heart contains mostly _______
Cardiac muscle
The two atria in the mammal heart have ____ walls and function___for blood returning to the heart
thin
collection chambers
The ventricles have___walls and contract much more___then the atria
thick
strongly
A___is one complete sequence of pumping, as the heart contracts, and filling, as it relaxes, and it’s chambers filled with blood
systole is the ______ phase
diastole is the ______ phase
cardiac cycle
systole
diastole
In diastole the atria and ventricles are at___
rest
0.4 sec
Atrial Systole: forsces all remaining blood out of the ____ and into the ______.
atria
ventricles
0.1 sec
Ventricular Systole: blood is pumped into ______
large arteries
0.3 sec
Cardiac output depends on which two factors
Heart rate and stroke volume which is the amount of blood pumped by the left ventricle in each contraction
What is the average stroke volume for a human
75 mL
What is the typical resting cardiac output
5.25 L per minute
How many valves are in the heart and what do they do
There are four and they prevent backflow and keep blood moving in the correct direction
What is an atrioventricular valve
Keeps blood flowing back into the atria when the ventricles contract
What are semi lunar valve’s
There are two sets one between the left ventricle and one between the right ventricle and they prevent backflow from vessels into the ventricles while they’re relaxing
What sets the rate and timing at which all cardiac muscle cells contract
the sinoatrial (SA) node or pacemaker
How does the SA node Make the eight year contract in unison
By generating electrical impulses
What physiological cues is the SA node influenced by
Two sets of nerves and hormones
