Circulatory Systems Flashcards
Diffusion
Molecular movement caused by thermal energy and it moves in Brownian motion (random)
When is diffusion used for and when is it slow?
It is used for when the cell distance is only 1-2 cells thick. It is slow when there is multiple cells as the cells in the back do not receive oxygen fast enough and die.
What does a circulatory system do?
Allow for bigger animals to get oxygen; speeds up transport of ions and molecules
Gastrovascular cavities
In Cnidaria and platyhelminthes; place many cells in contact w/ environment; acts as a stomach (eats and does digestion)
What are the two circulatory systems?
Open and closed
Open circulatory system
In arthropods and molluscs (except cephalopods); contains hemolymph; does not form a complete circuit and not connected w/ respiratory system; blood flows in body and gets pumped back to heart due to contraction of heart and movement of animal
Hemolymph
Blood mixed w/ interstitial fluid
Closed circulatory system
In earthworm and us; all vessels form one complete closed network that all blood travels through; blood does not leave vessels unless injury
Water vascular system
In echinoderms; hydraulic system functions in locomotion, respiration, food and waste transportation; uses sea water instead of blood or hemolymph
What does the circulatory system move?
Oxygen, sugars, hormones, antibodies, waste (CO2 and urea), and pathogens
Blood
Connective tissue made of cells, platelets, and plasma
How much plasma, leukocytes and platelets, and erythrocytes are in blood?
Plasma: 55%
Leukocytes and platelets: <1%
Erythrocytes: 45%
Erythrocytes
Red blood cells that contain hemoglobin; mammalian red blood cells have no nucleus which makes room for hemoglobin but they also die faster; disk-like and concave
Hemoglobin
Contains iron to carry oxygen in erythrocytes
Leukocytes
White blood cells that defend against pathogens; have a nucleus
Platelets
Cell fragments of old red blood cells; form clots (for injury)
Plasma
Fluid that is 95% water and contains ions, glucose, hormones, and proteins
What are the 3 types of vessels that transports blood?
Arteries, veins, and capillaries
Arteries
Take blood away from heart; thin diameter w/ a ring of a thick layer of smooth muscle allows it to change diameter and blood pressure; pumps blood at a high pressure due to it being from heart; small diameter=fast
Veins
Bring blood towards the heart; blood moves slow; has valves to prevent backflow
Capillaries
Site of gas/solute exchange
What are the three types of hearts?
Two chamber, three chamber, and four chamber
Two chambered heart
Primitive and one circuit allowing for single circulation; in fish; blood -> lungs -> body
Three chambered heart
In amphibians; allows for double circulation; 1 ventricle
Four chambered heart
In mammals and archosauria; allows for double circulation; two ventricles
What is the difference between single circulation and double circulation?
Having a dedicated body for systemic circuit and respiratory (pulmonary) circuit allows greater oxygen absorption and delivery
What kind of heart do crocodiles have?
They have a 4 chambered heart that has a foramen of Panizza which allows it to act like both a 4 chambered and 3 chambered heart. This allows for crocodiles and other reptiles to dive for over long periods of time and have special hemoglobin oxygen release systems.
Foramen of Panizza
Allows blood to bypass the pulmonary circuit; functionally connects the two vent field; opens=3 chambers, closes=4 chambers
Special hemoglobin oxygen release system
Only releases oxygen from hemoglobin when needed; in crcodiles
Valves
Prevent back flow; include: Semilunar valves, Tricuspid and Bicuspid valves (atrioventricular valves)
Difference between semilunar and atrioventricular?
Atrioventricular valves are between atrium and ventricle while semilunar valves are from ventricles to outside of heart.
Left atrium
Where oxygenated blood enters; top
Right atrium
Where deoxygenated blood enters; top
Ventricles
Does the pumping; bottom
Sinoatrial node
Pacemaker-triggers each heartbeat; is a cardiac muscle, can respond to adrenaline=make heart pump faster
What is the order of signal from the SA node?
SA node -> delay at AV node -> bundle branches to heart apex -> Purkinje fibers and spreads throughout ventricles causing contraction
