Physiology of lips and nails MCQs With Answer

Introduction: This set of MCQs on the physiology of lips and nails is designed specifically for M.Pharm students studying Herbal Cosmetics (MPG 204T). The questions review detailed anatomical, histological and physiological features that influence formulation and therapeutic strategies for lip and nail care. Topics include structure and function of vermilion border, mucocutaneous junction, nail matrix and plate, vascular and neural supply, rates and regulators of growth, and clinical signs relevant to systemic and topical interventions. Understanding these fundamentals helps pharmacists and cosmetic scientists select active herbal ingredients, design delivery systems, and recognize how systemic conditions affect cosmetic outcomes.

Q1. Which structural feature primarily explains the red color of the vermilion zone of the lips?

• High melanin content in lip epidermis
• Thin, translucent epithelium showing underlying capillary bed
• Abundant sebaceous glands producing pigmented sebum
• Presence of specialized red chromophores in keratin

Correct Answer: Thin, translucent epithelium showing underlying capillary bed

Q2. The mucocutaneous junction of the lip marks the transition between which two tissue types?

• Keratinized epidermis and non-keratinized oral mucosa
• Dermis and subcutaneous fat
• Skeletal muscle and adipose tissue
• Glandular epithelium and cartilage

Correct Answer: Keratinized epidermis and non-keratinized oral mucosa

Q3. Which statement best describes the distribution of sweat and hair follicles on the vermilion border of the lips?

• Abundant eccrine sweat glands and terminal hair follicles
• Presence of hair follicles but absence of sweat glands
• Absence of both sweat glands and hair follicles
• Only apocrine glands are present

Correct Answer: Absence of both sweat glands and hair follicles

Q4. Which arteries are the primary blood supply to the upper and lower lips?

• Superior and inferior labial branches of the facial artery
• Angular and dorsal nasal arteries
• Infraorbital and mental arteries
• Superficial temporal and maxillary arteries

Correct Answer: Superior and inferior labial branches of the facial artery

Q5. The high transepidermal water loss (TEWL) of lips compared with adjacent facial skin is mainly due to:

• Thicker stratum corneum on the lips
• Absence of sebaceous and sweat glands and thinner stratum corneum
• Greater density of melanocytes causing water pores
• Higher number of eccrine sweat glands promoting evaporation

Correct Answer: Absence of sebaceous and sweat glands and thinner stratum corneum

Q6. Which type of keratin predominates in the nail plate and confers its hardness?

• Soft epithelial keratin with low disulfide bonds
• Hard keratin rich in sulfur-containing proteins and disulfide bonds
• Elastin-rich fibrous keratin
• Collagen type IV keratin complex

Correct Answer: Hard keratin rich in sulfur-containing proteins and disulfide bonds

Q7. The nail matrix is responsible for which primary function?

• Anchoring the nail plate to the nail bed
• Generating the cells that form the nail plate
• Producing sebum to lubricate the nail fold
• Providing sensory innervation to the fingertip

Correct Answer: Generating the cells that form the nail plate

Q8. The visible half-moon pale area at the proximal nail plate is called the lunula and represents:

• Distal hyponychium keratinization
• Visible portion of the nail matrix where keratinization is incomplete
• Accumulated pigment in the nail bed
• Avascular dead tissue detached from the nail bed

Correct Answer: Visible portion of the nail matrix where keratinization is incomplete

Q9. Approximately how fast do healthy adult fingernails grow under normal conditions?

• About 0.1 mm per month
• About 1 mm per month
• About 3 mm per month
• About 10 mm per month

Correct Answer: About 3 mm per month

Q10. Which neural branches supply sensory innervation to the upper and lower lips respectively?

• Infraorbital nerve (V2) to upper lip; mental nerve (V3) to lower lip
• Facial nerve (VII) to upper lip; glossopharyngeal (IX) to lower lip
• Trigeminal mandibular branch (V3) to upper lip; infraorbital (V2) to lower lip
• Hypoglossal nerve to both upper and lower lips

Correct Answer: Infraorbital nerve (V2) to upper lip; mental nerve (V3) to lower lip

Q11. Beau’s lines on the nail plate are best described as:

• Longitudinal pigmented streaks caused by melanin
• Transverse grooves indicating temporary matrix arrest
• Periungual inflammation due to bacterial infection
• Localized nail plate thickening from trauma

Correct Answer: Transverse grooves indicating temporary matrix arrest

Q12. Koilonychia (spoon nails) is classically associated with which systemic deficiency?

• Vitamin C deficiency
• Iron deficiency anemia
• Hypervitaminosis A
• Calcium excess

Correct Answer: Iron deficiency anemia

Q13. Onycholysis, the separation of the nail plate from the nail bed, is commonly caused by:

• Excessive topical oiling of nails
• Fungal infection, trauma, or hyperthyroidism
• Increased melanin production in the nail matrix
• Dehydration alone without other factors

Correct Answer: Fungal infection, trauma, or hyperthyroidism

Q14. Which physiologic change during pregnancy typically affects nail growth?

• Marked decrease in nail growth due to estrogen suppression
• Accelerated nail growth due to increased circulation and hormones
• Complete cessation of nail matrix activity
• Conversion of nail plate keratin to mucin

Correct Answer: Accelerated nail growth due to increased circulation and hormones

Q15. In formulating herbal lip products for hydration and barrier repair, which property of the vermilion zone must be primarily considered?

• High density of eccrine glands requiring aqueous gels
• High TEWL and lack of sebaceous glands requiring occlusive and emollient agents
• Excessive keratinization preventing ingredient penetration
• High melanin binding affecting whitening actives only

Correct Answer: High TEWL and lack of sebaceous glands requiring occlusive and emollient agents

Q16. Melanonychia (longitudinal pigmented bands in the nail) can result from:

• Increased melanin production in the nail matrix
• Accumulation of keratin only
• Reduced blood flow to the nail bed
• Excessive hydrating agents on the nail

Correct Answer: Increased melanin production in the nail matrix

Q17. The eponychium (cuticle) functions primarily to:

• Generate the nail plate
• Seal the proximal nail fold and protect the matrix from pathogens
• Provide pigmentation to the nail plate
• Produce sebum for the entire fingertip

Correct Answer: Seal the proximal nail fold and protect the matrix from pathogens

Q18. Which systemic disease commonly manifests as nail clubbing?

• Chronic hypoxic lung disease such as bronchiectasis or lung carcinoma
• Acute localized bacterial skin infection only
• Isolated iron overload without pulmonary involvement
• Vitamin B12 deficiency alone

Correct Answer: Chronic hypoxic lung disease such as bronchiectasis or lung carcinoma

Q19. Which herbal ingredient is often used in lip formulations for mild keratolytic and softening effects to improve exfoliation?

• Aspirin (acetylsalicylic acid) synthetic only
• Glycolic acid synthetic exclusively
• Natural fruit acids (AHA) such as lactic or malic acid from fruit extracts
• High concentrations of chlorine compounds

Correct Answer: Natural fruit acids (AHA) such as lactic or malic acid from fruit extracts

Q20. In assessing nail changes for topical medicated nail delivery, why is understanding the nail plate’s composition important?

• Because the nail plate has abundant blood vessels allowing systemic delivery
• Because the hard keratin structure and low permeability determine choice of solvents and penetration enhancers
• Because nails are composed mainly of adipose tissue that absorbs lipophilic drugs
• Because the nail plate is highly acidic and degrades most actives

Correct Answer: Because the hard keratin structure and low permeability determine choice of solvents and penetration enhancers

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