Usually is only because of blood vessels breaking in the skin.
Answer:
a. veins and arteries
b.diaphragm
c.kidney
d.lung
e.4
f.left auricle(atrium) , right auricle(atrium)
g.left ventricle, right ventricle
h.blood plasma
i.digestive
j.buccal cavity ,saliva
k.bile
l.excretory
m.kidneys
Explanation:
Keratin is an intracellular fibrous protein that gives hair, nails, and skin their hardness, strength, and water-resistant properties. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from the deeper layers
Hope this helped!
Good luck :p
~Emmy <3
About 65 days after planting