Histology Testbank: Skin 4a

Instructions: For each histology question, pick the one best answer. This histology test bank is also useful for the histology questions on the USMLE (USMLE step 1).

1.
Which of the following is composed of stratified squamous epithelium?
a. Epidermis
b. Dermis
c. Hypodermis
d. Both a and b
e. Both b and c

Answer: a

The skin is composed of two layers: the epidermis and the dermis. Underneath these layers lies the hypodermis. The epidermis is stratified squamous epithelium. The dermis is composed of a papillary layer and a reticular layer. The reticular layer of the dermis is made up of dense irregular connective tissue. The hypodermis is a layer of loose connective tissue.

2.
Which of the following is NOT a function of skin
a. Vitamin D production
b. Protection from water loss
c. Sensory reception
d. Heat regulation
e. All are functions of skin

Answer: e

The skin is involved in the production of vitamin D from precursors with the aid of the sun. It protects the body from water loss. There are many sensory receptors in the skin: pain, pressure, fine touch. The skin is also involved in heat regulation. In addition, the skin protects the body.

3.
Which layer of the epidermis contains dividing cells?
a. Stratum basale
b. Stratum spinosum
c. Stratum granulosum
d. Stratum lucidum
e. Stratum corneum

Answer: a

The epidermis is divided into five layers: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.

The stratum basale contains the dividing cells. This layer is also called the stratum germinativum.

The stratum spinosum consists of a layer several cells deep. The cells have pointy or spiny processes on them. The cells in the stratum granulosum contain keratohyaline granules.

The stratum lucidum is present only in thick skin.

The stratum corneum is the outermost layer. The cells in this layer are essentially bags of keratin. They contain no nuclei or organelles.

Note from Sarah Bellham: My favorite mnemonic for remembering the layers of the skin: "Californian Ladies Give Superb Backrubs"

4.
Which layer of the epidermis contains cells with no nuclei or organelles?
a. Stratum basale
b. Stratum spinosum
c. Stratum granulosum
d. Stratum lucidum
e. Stratum corneum

Answer: e

The epidermis is divided into five layers: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.

The stratum basale contains the dividing cells. This layer is also called the stratum germinativum.

The stratum spinosum consists of a layer several cells deep. The cells have pointy or spiny processes on them. The cells in the stratum granulosum contain keratohyaline granules.

The stratum lucidum is present only in thick skin.

The stratum corneum is the outermost layer. The cells in this layer are essentially bags of keratin. They contain no nuclei or organelles.

Note from Sarah Bellham: My favorite mnemonic for remembering the layers of the skin: "Californian Ladies Give Superb Backrubs"

5.
Which cell is a phagocyte?
a. Langerhans cell
b. Keratinocyte
c. Melanocyte
d. Merkel cell
e. Fibroblast

Answer: a

Langerhans cells, keratinocytes, melanocytes, and Merkel cells are all found in the epidermis. The Langerhans cell is a phagocyte. The keratinocyte is the most abundant cell in the epidermis. The melanocyte produces melanin, which is responsible for skin pigmentation. The Merkel cell is a mechanoreceptor.

Fibroblasts are found in the dermis. Fibroblasts produces collagen.

6.
What is a characteristic of the cells in the epidermis of the skin?
a. Microvilli
b. Stereocilia
c. Cilia
d. Keratinization
e. Both a and b

Answer: d

Microvilli are the finger like projections seen on the surface of some cells. The appearance of microvilli form what is also called the brush border or striated border.

Stereocilia are very long microvilli. Stereocilia are seen in the epididymis and the hair cells of the ear.

Cilia is the hair like surface modification seen on some epithelia. Cilia are made of microtubules.

Keratinization is seen in the epidermis. Cells in the stratum corneum are essentially just bags of keratin.

7.
Where are apocrine sweat glands NOT found?
a. Areola
b. External genitalia
c. Posterior neck
d. Axilla
e. Circumanal region

Answer: c

Sweat glands are divided into apocrine and eccrine. Apocrine sweat glands are found on the areola, external genitalia, axilla, and curcumanal region. Eccrine sweat glands are distributed over most of the body.

8.
What is the innervation of an apocrine sweat gland?
a. Cholinergic; parasympathetic
b. Cholinergic; sympathetic
c. Adrenergic; parasympathetic
d. Adrenergic; sympathetic
e. Cholinergic; motor

Answer: d

Apocrine sweat glands are innervated by the sympathetic nervous system. The neurotransmitter for the apocrine sweat glands is norepinephrine. Thus it is adrenergic.

9.
Which of the following is a receptor for fine touch which is located in the dermis?
a. Free nerve endings
b. Ruffini's corpuscles
c. Pacinian corpuscles
d. Krause's end bulbs
e. Meissner's corpuscle

Answer: e

There are several different sensory receptors in the skin. The most abundant sensory receptor are the free nerve endings. Free nerve endings respond to pain and temperature. Ruffini's corpuscles respond to continuous pressure. Pacinian corpuscles respond to vibration and rapidly changing pressure. Krause's end bulbs are a receptor for fine touch which are located in mucous membranes and the tongue. Meissner's corpuscles are also a receptor for fine touch but they are located in the dermis.

10.
Which of the following is found in the hair follicle?
a. Henle's layer
b. Bipolar cells
c. Amacrine cells
d. Rods
e. Ganglion cells

Answer: a

Bipolar cells, amacrine cells, rods, and ganglion cells are all part of the retina.

Henle's layer is a layer in the hair follicle.