Circulatory System Flashcards
Cyclosis
Streaming of cytoplasm
Unicellular organisms
No need for circulatory system , materials move into and out of the cell by diffusion and osmosis
Cnidarians
Most cells are in contact with the external environment …exchange of nutrient and wastes can take place directly
Annelida
Simple closed circuits of blood vessels with five small hearts which are really just pulsating vessels
Insects and other Arthropoda
Open circulatory system that bathes their internal organs ;consist of on dorsal vessel that pulsate, keeping the blood moving through out the body; blood does not carry oxygen
Arteries
Carrie blood away from heart, thick elastic muscular walls that dilate or contract to control blood pressure within vessels, arterial blood pressure tends to be high , usually rich in oxygen since it is being pumped out to the body to provide oxygen and bring nutrients to the cells(except for in pulmonary circulation ), exceptions are the pulmonary arteries
Capillaries
Smallest are one cell thick allowing nutrient waste products oxygen and carbon dioxide to diffuse between the blood and the surrounding tissues
Veins
Carry blood toward heart, blood pressure and forward momentum of the blood in veins is more than in arteries,blood is pushed along the contractions of the skeletal muscles when the organism moves around , usually carry deoxygenated blood except of pulmonary circulation , contain unidirectional valves
Fish
Has two chambered heart , one closed loop and blood is pumped from heart to the full capillaries where oxygen picks up from the surrounding water , inefficient because the blood loses a lot of momentum in the film capillaries. After leaving the gill capillaries it travels slowly and with a lower pressure affecting the delivery of oxygen to the blood tissue
Amphibians reptiles birds and mammal
Two circuits within the circulatory system , pulmonary and systemic circulation , after the blood is pumped from the heart to the lungs to be oxygenated it is returned to the heart before it is pumped out to the rest of the body
Pulmonary circulation
To and from lungs
Systemic circulation
To and from the rest of the body
Amphibians and reptiles hearts
Three chambers and is inefficient because oxygen poor and rich blood is still mixed
Birds and mammals hearts
Four chambers composed of cardiac muscle , two halves, one for oxygenated and deoxygenated blood , each half has a atrium and ventricle
Atrium
Blood returns to the heart(top)
