CPS Anatomy of Skin & Hair 3 — Questions and Answers
Question 1: Which stage of the hair growth cycle is characterized by active cell division in the hair bulb?
- Catagen
- Telogen
- Anagen (Correct answer)
- Exogen
Correct answer: Anagen
During anagen, the hair bulb's matrix cells divide rapidly, pushing the hair shaft upward and lengthening the hair.
Question 2: What is the primary function of the stratum corneum in a pet's skin?
- Produce melanin for pigmentation
- Form a physical barrier against pathogens and water loss (Correct answer)
- Anchor hair follicles to the dermis
- Synthesize vitamin D from UV exposure
Correct answer: Form a physical barrier against pathogens and water loss
The stratum corneum is the outermost layer of the epidermis composed of dead, keratinized cells that protect against environmental insults and transepidermal water loss.
Question 3: What term describes the natural shedding of dead skin cells from the outermost epidermal layer?
- Keratosis
- Desquamation (Correct answer)
- Cornification
- Epilation
Correct answer: Desquamation
Desquamation is the normal sloughing of corneocytes from the stratum corneum as new cells push upward from below.
Question 4: In cats, which anatomical feature makes their skin significantly more mobile than a dog's skin relative to body size?
- A thicker hypodermis layer
- Looser dermal collagen fiber arrangement (Correct answer)
- More arrector pili muscles per follicle
- A higher density of elastic fibers in the epidermis
Correct answer: Looser dermal collagen fiber arrangement
The loosely organized collagen fibers in feline dermis allow greater skin mobility, which is an evolutionary adaptation for escaping predators and absorbing bite wounds.
Question 5: Which protein is the primary structural component of both the hair shaft and the outer epidermal layers?
- Collagen
- Elastin
- Keratin (Correct answer)
- Fibronectin
Correct answer: Keratin
Keratin is a fibrous structural protein that gives hair its strength and forms the tough, waterproof outer skin layers through a process called keratinization.
Question 6: When a groomer clips 'against the grain,' what skin anatomy consideration is most important?
- The depth of the hypodermis
- The direction of follicle angle and potential for clipper burn (Correct answer)
- The density of Meissner corpuscles in the dermis
- The thickness of the stratum granulosum
Correct answer: The direction of follicle angle and potential for clipper burn
Clipping against the grain (against follicle angle) cuts closer and increases friction heat risk, potentially causing clipper burn on sensitive skin, especially thin-skinned areas.
Question 7: The dermal papilla, located at the base of the hair follicle, plays what critical role?
- Secreting sebum to lubricate the hair
- Supplying nutrients and growth signals to the hair matrix cells (Correct answer)
- Anchoring the hair to the epidermis via hemidesmosomes
- Producing melanin granules for hair color
Correct answer: Supplying nutrients and growth signals to the hair matrix cells
The dermal papilla is a cluster of mesenchymal cells and capillaries that signals and nourishes the hair matrix, directing growth and follicle cycling.
CPS Anatomy of Skin & Hair 3
Which stage of the hair growth cycle is characterized by active cell division in the hair bulb?