Card Set Information
BIO 220 Test Two
Every vertebrate heart is made of __ layers
What are they?
Continuous with the vessels that enter or leave the heart= endothelium (simple squamous)
Thickest layer to the wall of the heart
Responsible for pumping action and contraction of the chambers
Connective tissue and simple squamous
Part of mesothelium
Visceral pericardium and epicardium are synonymous terms
how many layers?
Serous membrane surrounding heart
Outer parietal pericardium
Inner visceral pericardium (epicardium)
Also the outer layer of the wall of the heart
Function of the Pericardium Function
: (like every serous membrane)
Protection, anchoring, reduction of friction as the organ moves in the same
Every vertebrate heart has at least one __and one __
Blood enters through atria
Veins dump blood into atria
Myocardial in atria are much thinner than myocardia of ventricles
Ventricles are __ chambers.
Blood leaves through ventricles
Arteries take blood away from ventricles
Ventricles are thicker in muscle because they have to push it to the body, while the atria just take it to the ventricles
Left ventricular walls are thicker walled than right ventricular walls
In three-chambered organisms:
if you look at the endothelium of htese chambers, what's wronge?
they're not always smooth
Endothelium atrial irregularities are called __.
When you look at the chamber, the wall isn’t smooth
Looks like teeth of a comb because the arrangement of the myocardium is irregular
Due to muscle arrangement
Endothelium ventricular muscular irregularities, are called __.
Appears to have nooks and crannies
Function of trabeculae carneae in three-chambered heart
Hold the blood; play a major role in preventing mixing of blood between the two valves (of oxygenated and deoxygenated blood
Between every ventricle and atrium is an __ valve
The valve that goes between an atria and a ventricle
Fucntion of AV valve
Prevents backflow back up into the atrium
AV Valve structure
Has a very elaborate structure
Two or more cusps (flaps)
Angled so pointing toward ventricle
Underneath cusps are a series of firbrous cords, called chorda tendinae
Chorda tendinae insert into mounds of muscles that jut into the wall called papillary muscles
Anchor chorda tendinae into ventricular wall
These chords and papillary muscles prevent everting
Anchorage prevents flaps from turning inside out
Cusps that are in the beginning of every artery that leaves the heart
Where are the semilunar valves located?
Pulmonary artery and the aorta or in terms of the two- chambered artery, the ventral aorta
How many cusps of semilunar valve?
Explain semilunar valve contraction and relaxation.
When ventricles contract, the cusps open up to go to the artery
When ventricles relax, the cusps close and you don’t get backflow
True or False:
Semilunar valves have anchorage and cusps/
Does not have anchorage, just has cusps