Epidermis

The Epidermis is composed of _____ ?

• Connective tissue

• Papillary region

• Keratinized stratified squamous epithelium

• Dense irregular connective tissue

Answer explanation

Keratinized stratified squamous epithelium is a type of stratified epithelium that contains numerous layers of squamous cells, called keratinocytes, in which the superficial layer of cell is keratinized. Besides skin, also found in areas of oral mucosa.

Which of the following is true of the Epidermis ?

• It contains the smallest vessels (capillaries)

• It is made of connective tissue

• It is made of simple squamous cells

• It is outermost layer of the cutaneous membrane

• All of answers

Answer explanation

The skin also known as the cutaneous membrane, cover the external surface of the body and is the largest organ of the body in weight.

Rearranged from the most superficial to the deepest.

• Hypodermis

• Dermis

• Epidermis

Answer explanation

Epidermis superficial and thinner portion, dermis deeper and thicker portion, Hypodermis is subcutaneous layer and deep to the dermis.

Below is true match the function of cells in epidermis EXCEPT

• Keratinocyte - Produce lamellar granules

• Langerhans cells - Participate in immune response

• Melanocyte - Produce the pigment melanin

• Markel cell - Protect skin from damaging ultraviolet (UV) light

Answer explanation

Markel cell or tactile epithelial cells function in sensation of touch along with the adjacent. Melanocytes produce the melanin which contribute to skin colour and absorbs damaging ultraviolet (UV) light.

What is the thick epidermis under free edge of nail ?

• Nail bed

• Hyponychium

• Nail matrix

• Eponychium

Answer explanation

Beneath the free edge is a thickened region of stratum corneum called hyponychium. It is the junction between the free edge and skin of the fingertip and secure the nail to the fingertip.

Below are the pigments contribute to skin colour EXCEPT

• Melanin

• Keratin

• Haemoglobin

• Carotene

Answer explanation

The amount of melanin causes the skin’s colour to vary from pale yellow to reddish-brown to black. The red colour of skin is due to haemoglobin, the oxygen-carrying pigment in red blood cells. Carotene is a yellow-orange pigment that gives egg yolks, and is stored in the stratum corneum. Keratin protects the skin underlying tissue.

​ ​ ​ (a)   is an area of skin present stratum Lucidum.​

• Soles
• Eyelids
• Armpit
• Elbow

Answer explanation

The stratum Lucidum is present only in the thick skin areas such as the fingertips, palms and soles.

Which layer of the epidermis present keratohyalin and lamellar granules ?

• Stratum spinosum

• Stratum corneum

• Stratum lucidum

• Stratum granulosum

Answer explanation

A distinctive feature of cells in stratum granulosum presence of darkly staining granules of a protein called keratohyalin. Also Lamellar granules which fuse with plasma membrane and release a lipid -rich secretion. Lipid-rich secretion act as a water -repellent sealant, retarding loss and entry of water and entry of foreign materials

Match the following cells

• Markel cells

• 
• Melanocytes cells

• 
• Langerhans cells

• 
• Keratinocytes cells

• 

Answer explanation

Do you know ?

Langerhans cells arise from red bone marrow. They participate in immune responses mounted against microbes that invade the skin, and are easily damaged by UV light.

It used to protect skin and underlying tissue from abrasion.

What is it ?

Answer explanation

Keratinocytes produce protein keratin. Keratin is a tough, fibrous protein that helps protect the skin and underlying tissues from abrasion, heat, microbes and chemical.