14) which of these contributes to the formation of the popliteal vein?
a) internal iliac
b) small saphenous and great saphenous
c) anterior and posterior tibial and fibular
d) peroneal and popliteal
e) great saphenous and posterior tibial
15) preganglionic neurons of the sympathetic nervous system are located in the
a) lateral gray horns of the cervical cord.
b) anterior gray horns of the cervical and thoracic spinal cord.
c) lateral gray horns of segments t1 to l2 of the spinal cord.
d) anterior gray horns of segments t1 to l2 of the spinal cord.
e) lateral gray horns of t1 to s2 of the spinal cord.
16) sperm develop from stem cells called
a) spermatogonia.
b) primary spermatocytes.
c) secondary spermatocytes.
d) spermatids.
e) spermatozoa.
17) excess hydrogen ion is eliminated from the body largely by
a) sweating.
b) the kidneys.
c) the liver.
d) the feces.
e) buffers.
18) the thoracic cavity contains the