Week 8 Flashcards
Closed circulatory system
blood moves through blood vessels
Open circulatory system
blood leaves blood vessels
Fish circuits
systemic circuit and gill circuit connect
Mammals and bird circuit
systemic circuit and lung circuit connect
Amphibian and reptiles circuit
have circulatory plans that dont anatomically guarantee series flow
Circulatory system
consists of muscular pump, fluid and series of conduits
how blood travels
heart pumps blood into arteries, which branch into smaller vessels, eventually into microscopic vessels. As blood leaves tissues, it flows into larger and larger vessels, the veins, back to the heart
Microcirculation
arterioles, capillaries and venules
capillary function
found near every tissue cell
princple site where blood releases O2, nutrients and hormones to tissues and takes up CO2 and other waste products from the tissue
Arterioles walls
walls have a layer of smooth muscle under the control of autonomic nervous system
vasoconstriction
contraction of muscle cells
vasodilation
relaxation of muscle cells
arteriole diameter - function
determines rate of blood flow through capillaries
Systemic tissues
all tissues and organs other than breathing organs, take up O2 from blood and add CO2 to the blood
Systemic circuit
blood vessels that carry blood to and from systemic tissues
Breathing circuits
add o2 to the blood and take up co2 from the blood
Breathing organ circuit
blood vessels that carry blood to and from breathing organs
Perfusion
flow of blood through a tissue or organ
myocardium
the muscle tissue of heart
stroke volume
volume of blood pumped per beat
Cardiac output
volume of blood pumped per minute
cardiac cycle
cycle of contraction and relaxation of the heart
systole
when ventricles contract
diastole
when ventricles relax
Blood pressure
extent to which the pressure in the blood exceeds the pressure in the environment
Hypertension
high blood pressure
plasma
contains glucose and nutrients
oxygenation
pigment combines with O2
deoxygenation
when pigment releases o2
respiratory pigments
bind to O2 to increase the amount that blood can carry
Hemocyanin
respiratory pigment in mollusks
hemocyanin - makeup
contains copper instead of iron and is in blood plasma not in cells, oxygenated turns blue
partial pressure
pressure exerted by a particular gas in a mixture of gases
how gases diffuse
down pressure gradients in the lungs and organs as a result of differences in partial pressure
Respiratory surfaces
where gases exchanged with the environment
rate of diffusion
proportional to surface area
respiratory area properties
tend to be thin and have large areas to maximise rate of gas exchange
Gills
outfoldings of body surface suspended in water
Tracheal system
air tubes that branch throughout the body
largest tubes open to outside, fine tubes branch to all cells
Lungs
hollow bags
Gill ventilation
ventilated by current of water that enters the mouth, passes through slits in pharynx, flows over gills
advantages of breathing air over water
much higher concentration of oxygen
less energy needed
less volume needed
Gas exchange on land
respiratory surface not in direct contact with all other parts so circulatory system trnsports gases to rest of body
dense network of capillaries under epithelium
Buccal breathing (amphibians)
positive pressure
muscles lower cavity floor drawing air through nostrils
nostrils and mouth closes forcing air down trachea
most gas exchange through skin
Negative pressure breathing
pulling air rather than pushing it into lungs
bird breathing
air sacs that act as bellows that keep air flowing through the lungs
