A physician observes blood vessels in a normal umbilical cord - which does he/she see on the cut end of the cord? 2 umbilical veins, 1 umbilical artery

1 umbilical vein, 2 umbilical arteries

1 umbilical vein, 1 umbilical artery

2 umbilical veins, 2 umbilical arteries

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave