Histology Testbank: Skin 3a

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.
The reticular layer is part of which layer?
a. Epidermis
b. Dermis
c. Hypodermis
d. Both a and b
e. None of the above

Answer: b

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 considered an epidermal appendage?
a. Sweat gland
b. Hair
c. Hypodermis
d. Nails
e. Sebaceous glands

Answer: c

Sweat glands, hair, nails and sebaceous glands are all considered epidermal appendages. The hypodermis is not considered an epidermal appendage. The hypodermis is the loose connective tissue layer underneath the dermis.

3.
Which layer of the epidermis is also called the stratum germinativum?
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 is on the surface of the skin?
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 the most abundant cell in the epidermis?
a. Langerhans cell
b. Keratinocyte
c. Melanocyte
d. Merkel cell
e. Fibroblast

Answer: b

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 type of epithelium forms the epidermis?
a. Simple squamous epithelium
b. Simple cuboidal epithelium
c. Simple columnar epithelium
d. Stratified squamous epithelium
e. Pseudostratified epithelium

Answer: d

The epidermis is formed by stratified squamous epithelium. Epithelium lines body cavities and surfaces. Stratified squamous epithelium is "stratified" because it is more than one cell layer thick. "Squamous" refers to the fact that the surface cells of the stratified squamous layer are flat. This is important to note as the cells at the basal layer are cuboidal or even columnar. It is still classified as "squamous" based on the cells of the surface layer.

7.
What is the portion of the nail which is underneath skin?
a. Lunula
b. Eponychium
c. Matrix
d. Nail bed
e. Root

Answer: e

The lunula is the half moon shaped white area on a nail. The anatomical term for the cuticle is the eponychium. The matrix is the region of the nails where there are dividing cells and nail growth. The nail plate rests on the nail bed. The nail root is the proximal portion of the nail that is underneath skin.

8.
What type of glands are the glands of Moll?
a. Endocrine gland
b. Apocrine sweat gland
c. Oil gland
d. Sebaceous glands
e. Eccrine sweat gland

Answer: b

The glands of Moll in the eyelid are apocrine sweat glands.

9.
Which of the following responds to vibration and rapidly changing pressure?
a. Free nerve endings
b. Ruffini's corpuscles
c. Pacinian corpuscles
d. Krause's end bulbs
e. Meissner's corpuscle

Answer: c

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 a receptor for fine touch which is located in mucous membranes?
a. Free nerve endings
b. Ruffini's corpuscles
c. Pacinian corpuscles
d. Krause's end bulbs
e. Meissner's corpuscle

Answer: d