BIO

The three main regions of an insect's anatomy are the __________, __________, and __________.

head, thorax, abdomen

A concentrated cluster of myocytes along the vascular route is referred to as a __________ heart.

globular heart

The evolutionary origin of the chambered heart of vertebrates is not fully __________.

known

In fish, the four chambers of the heart are the __________, __________, __________, and __________.

sinus venosus, atrium, ventricle, conus arteriosus

The __________ circuit refers to the blood flow from the heart to the lungs.

pulmonary

Birds and mammals have __________-chambered hearts consisting of two atria and two ventricles.

four

The deoxygenated blood from the right atrium passes to the right ventricle through the __________ valve.

tricuspid

The valve on the left side of the heart is known as the __________ valve.

mitral or bicuspid

After blood is oxygenated in the lungs, it returns to the heart via the __________ veins.

pulmonary

The main purpose of the heart is to pump blood through the body in a repeating sequence called the __________ cycle.

cardiac

Systolic blood pressure measures the pressure of blood when the heart is __________.

beating

The condition where blood flow is blocked by fatty plaques is called __________.

atherosclerosis

The muscles controlling blood flow into capillary beds are known as __________ sphincters.

precapillary

The fluid that drains from capillaries into lymphatic vessels is called __________.

lymph

Giraffes require a blood pressure of __________ mm Hg to pump blood to their heads.

250

The __________ __________ prevents blood from flowing backward in veins.

one-way valves