Question

question 25 (1 point)
which part of the nail unit is richly supplied with blood vessels and with nerves?
a lunula
b nail bed
c nail plate
d nail folds

question 26 (1 point)
what is a fibrous protein that is the principal component of hair and nails?
a dermal papillae
b collagen
c elastin
d keratin

question 27 (1 point)
which term refers to a layer that protects the hair from penetration and prevents damage to hair fibers?
a cortex
b hair follicle
c medulla
d hair cuticle

Explanation:

Question 25

The nail bed is the part of the nail unit that has a rich supply of blood vessels and nerves. The lunula is the white crescent - shaped area, the nail plate is the hard part of the nail, and nail folds are the skin folds around the nail. So the correct option is the one corresponding to the nail bed.

Keratin is the fibrous protein that is the main component of hair and nails. Dermal papillae are related to the dermis and hair follicles, collagen is more related to connective tissues like skin (but not the main component of hair and nails), and elastin is for elasticity in tissues. So the correct option is the one with Keratin.

The hair cuticle is the outermost layer of the hair that protects it from penetration and damage to the hair fibers. The cortex is the middle layer with pigment and strength, the hair follicle is the structure that produces hair, and the medulla is the innermost (sometimes absent) layer of the hair. So the correct option is the one with Hair cuticle.

Answer:

b. Nail bed

Question 26