heart Flashcards
DIFFERENCES IN FISH AND MAMMAL HEARTS
fish - single loop circulatory system where blood passes through the heart once per circuit/two-chambered - blood is oxygenated through the gills before being pumped to the rest of the body
mammals - double-loop circulatory system where blood passes through the heart TWICE per circuit/four-chambered - separation of oxygenated and deoxygenated blood, leading to efficient transport of oxygen to tissues
Skeletal vs cardiac muscles (5 pts.)
cardiac muscles are myogenic
Arteries
moving blood AWAY from the heart
Aorta
Carries oxygenated blood to the body from the left ventricle
Very thick, elastic muscle wall; can withstand very high pressure
Pulmonary artery
Four branches carry deoxygenated blood from the right ventricle to the right and left lungs
Thick, elastic muscle wall to withstand and maintain high pressure (although not as much as is generated in the aorta)
Coronary arteries
Arteries visible on the external surface of the heart
Carry the freshest, oxygenated and nutrient rich blood from the aorta to the heart muscle itself
Veins
Moving blood TOWARDS the heart
Superior vena cava and Inferior vena cava
Superior vena cava
- Brings deoxygenated blood from the head and upper body to the right atrium
- Large diameter, thin muscle wall, little pressure.
Inferior vena cava
- Brings deoxygenated blood from the lower body to the right atrium
- Large diameter, thin muscle wall, little pressure
Pulmonary vein
Bring oxygenated blood from the right and left lungs to the left atrium
Thin-walled, low pressure.
Cardiac veins
Veins visible on the external surface of the heart
Carry deoxygenated blood from the capillaries in the heart back to the right atrium
Remove wastes from the heart muscle
Pocket Valves
found in the blood vessels
leaving the heart:
- aortic & pulmonary semilunar valve (both have 3 semilunar cusps)
OTHER 2 TYPES OF valves:
tricuspid valve (blocks backflow from the right ventricle into the right atrium) & bicuspid valve (prevents backflow from the left ventricle into the left atrium)
WHY DO WE HAVE VALVES?
Valves prevent backflow of blood and keep the blood moving in one direction through the heart.
The transport system
nutrients, oxygen, heat, and hormones through a network of arteries, veins, and capillaries.