EXERCISE 18: THE FROG CIRCULATOR SYSTEM (BLOOD VASCULAR SYSTEM)

Question 1

an enclosing double layered sac.

Answer 1

pericardium

Question 2

conical, thick muscular-walled posterior portion.

Answer 2

ventricle

Question 3

thin-walled portions anterior to the ventricle; the division between the atria is not visible externally

Answer 3

left and right atria

Question 4

thickened muscular tube at the right side of ventricle; extends obliquely and divides anteriorly into two trunks.

Answer 4

conus arteriosus

Question 5

two large trunks anterior to conus arteriosus.

Answer 5

truncus arteriosus

Question 6

partition separating the left and right atria.

Answer 6

interatrial septum

Question 7

large opening in the right atrium through which blood enters the sinus venosus.

Answer 7

sino-atrial aperture

Question 8

small flaps guarding the sino-atrial aperture which prevent backflow of blood.

Answer 8

sino-atrial valve

Question 9

large opening through which both atria empty into the
ventricle.

Answer 9

atrio-ventricular aperture

Question 10

S-shaped longitudinal fold attached along dorsal wall of the conus arteriosus.

Answer 10

Spiral Valve

Question 11

opening at left atrium.

Answer 11

opening of pulmonary vein