Circulatory system Flashcards
What doesnt have a circulatory system
parazoans and simple metazoans(flat worms)
-exchange of 02 and nutrients with environment is achieved via moevemtn of water
Nematodes-fluids within bgody cavity are used for circulation
Open circulatory system
no distraction between blood and the extracellular (interstitial) fluids of body tissues eg) arthropods, and mollusks except cephalopods)
insect circulatory system
Open
blood is pumped through vessels into body cavity
Hemolymmph transports nutrients and metabolic waste, but ton o2 and CO2
heart with ostia
crustacean and chelicerates circulatory system
open ssystem
Hemolypm also transports o2 and co2. blood has oxygen-binding pigments, hemocyanin, not hemoglobin)
Function of blood (in vertebrates)
Transportation-all substances essential to cellular metabolism are transported by the circulatory system
-red blood cells transport oxygen to tissues
-blood carries absorbed products of digestion to cells in the body
-metabolic wastes and excess water in the blood are filtered through the kidneys
regulation-transports hormones participates in temp regulation
protection-circulatory system protects against injury and foreign substances
1)blood clotting platelets adhere to the damaged area
2)immune defense-white blood cells
closed circulatory system
blood is enclosed within vessels that transport the blood away from and back to heart, transports nutrients metabolic waste, and o2/co2
eg) annelids, cephalopod mollusks,
Fish circulatory system
single-looped circulation; low blood pressure
heat-gills body, back to heart
-in the transition to lungs some aortic arches of the kills were repurposed to deliver deoxygenated blood to paired air sacs associated with pharynx
tetrapods circulatory system
-the evolution of lungs coincided with the evolution of double-looped circulation
-blood is pumped via the pulmonary circuit from the heart to the lungs and back
-blood is pumped via the systemic circuit from the heart to the tissues and back
Mammals, birds, crocodiles-4 chambered heart so deox blood and ox blood don’t meat
Amphibians and most reptiles circulatory system
reptiles amphibians- 3 chamber heart so deox and o blood meet(two atria and one ventricle)
crocodiles, birds and mammals reptiles amphibians- 3 chamber heart so deox and o blood meet(two atria and one ventricle)
Mammals, birds, crocodiles-4 chambered heart so deox blood and ox blood don’t meat
Which chamber pumps oxygenated blood out ot body tissue
Left ventricle-thicker walls, high pressure
Right ventricle pumps deox blood to the lungs at low pressure
Mammal, bird croco heart
veins return blood, arteries take blood way from heart
1)Right atrium receives venous blood
2)blood flows to right ventricle and is pumped to lungs
3)left atrium receives ox blood from lungs
4)blood flows to left ventricle and is pumped to organs in body(via aorta)
- 2 cycle pump: atrial chambers pump simultaneously followed by ventricular chambers
blood vessels
arteries and arterioles
-blood leaves the heart via arteries and then to arterioles
-contain more elastic fibers than other blood vessels.. When they contract they reduce heat loss and limits blood flow to injured vessels
Capillaries
-upon leaving the arterial system blood then enters an elaborate network of capillaries
o2 is released to cells and co2 and other waste products are picked up
Venules and veins
-blood flows from venues and veins back to heart, aided by contractions of skeletal muscle
-low pressure, most of body blood is contained in veins, pooling of blood causes varicose veins (bed ridded)
Vasoconstriction
arteries and arterioles
When they contract they reduce heat loss and limits blood flow to injured vessels
Vasodilation
Increases heat loss, more blood flow
Capillaries
Capillaries
-upon leaving the arterial system blood then enters an elaborate network of capillaries
o2 is released to cells and co2 and other waste products are picked up
Venules and veins
Venules and veins
-blood flows from venues and veins back to heart, aided by contractions of skeletal muscle
-low pressure, most of body blood is contained in veins, pooling of blood causes varicose veins (bed ridded)
lymphatic system
-the circulatory system is a closed system; however some water and solutes of blood plasma filter through capillaries and form interstitial fluid
-the amount of fluid that flows out of capillaries is greater than what flows in. The remainder renters the lymphatic system(open system)
-excess interstitial fluid drains into lymph capillaries, which eventually passes to lymph nodes (in neck) and drained back into veins
Gas exchange across respiratory surfaces
respiration involes the diffusion of gases across plasma membrane
-diffusion is passive, driven by the difference in o2 and co2 concentrations across a membrane.
-ficks law of diffusion
ficks law of diffusion
R= (DxAxDeltap)/d
r=rate of diffusion
D=diffusion constant
A=surface area
deltap=difference in concentration on either side of membrane
d=width of membrane
-R can be increased by increased A, deltap or lowering d
Aquatic breathers
Undirectional- in mouth out gills
Terestial air-breathers
bidirectional or tidal in mouth, goes out the opposite way
birds have one way airflow
Gills
-gills are specialized vascularized filamentous structures that project into water. their design increased surface area (A) and minimized membrane width (d) for efficient gas exchange
-papulae and tube feet in echinoderms serve as gills
-naked gills in nudibranch(type of gastropod
-many marine annelids breathe through their skin
-aquatic insect larvae have external gills that connect to their tracheal system, lost as an adult
-gills are found in most encrustations, many mollusks and annelids, as well as larval salamanders and fish
-numerous groups of fish have evolved accessory breathing organs to cope with low dissolved o in water
Countercurrent exchange and fish law of diffusion
if fished used concurentis fish would have no diffusion as water and blood would be 50/50
numerous groups of fish have evolved accessory breathing organs to cope with low dissolved o in water
catfish absorb air through the digestive tract
-eclectic eels absorb air in their mouth cavity
-some fish fulp air and absorb o2 in specialized labyrinth organs
-lungfishs have paired longs that have same lungs as tetrapods’ origins
-some turtles diffuse o2 and cos across the membrane of their cloaca while underwater in winter (butt)
Trachael systems
Terrestial arthopods breathe via a network of air-fulled tubes (tracheae and air sacs) that branch into finer tubes (tracheoles) where gas exchange occurs. air enters and exits via spiracles.
circulatory system is NOT involved with gas exchange
aire enters through abdominal spiracles and exits through posterior spiracles. abdominal pumping improves circulation-
Lungs
are air chambers with internal support and a moist environment to reduce water loss
-vertebrate lungs(some fish)
-book lungs in spiders
-mantle cavity of terrestrial molluks
Tretrapods, evaportation across membrane surfaces minimized by moring air into moist, high vascularized paired chambers.
amphibian lungs
simple b/c they breath through skin, small lungs
2way airflow,, cutaneus airflow
Reptile lungs
more convoluted lungs increase surface area
2 way airflow
mammal lungs
increase surface area, more convuluted and aveloi
2 way airflow
bird lungs
air sacs and lungs, air doesnt go in and out bu it goes trhough- one way airflow.
Amphyians breathing
in amphibians, the interal surface area of lungs is relatively small. cutaneous breathing supplement lungs
-postive pressure breathing, air taken into mouth, nostrils close floor of mouth raised, air pushed into lungs, expelled by elastic forced
reptile breathing
-lungs have more convulations than amphibian, few can breath cutaneous. Negative pressure- rib cage expands to create negative pressure that draws air into lungs
mammals breathing
Two-way air flow allows mixing of fresh and stale air
-alveoli increase surface area for improved gas exchange
-Air drawn into lungs by negative pressure
-contraction of intercostal muscles raises ribs and expands thoracic cavity; contraction of diaphragm lowers base of thoracic cavity
-relaxation of these muscles allows elastic forces to expel air
birds breathing
one-way airflow, through their lungs (parabronchi_ which presents mixing of o2 and co2
inhale 1- oxygen enter postererior air sac.
Exhale1) oxygen moves into lungs and passes over parabronchi (air vessels)
inhale 2)-depleted oxygen leaves lungs and moves to air sacs
exhale 2) depleted oxygen leaves body
no mixing of deox and ox blood