B2M3 Flashcards
Which layer of the epidermis is present in thick skin but absent in thin skin?
A. Stratum basale
B. Stratum spinosum
C. Stratum lucidum
D. Stratum corneum
C. Stratum lucidum
Melanin is synthesized in which unique organelles of the melanocytes?
A. Melanosomes
B. Exosomes
C. Endosomes
D. Melanocytes
A. Melanosomes
Which is the deep layer of the skin that develops from the underlying mesenchyme?
A. Epidermis
B. Peridermis
C. Dermis
D. Hypodermis
C. Dermis
Which of the following stages refers to the development of the epidermis and dermis?
A. Morphogenesis
B. Differentiation
C. Specification
D. Biogenesis
C. Specification
Which of the following stages refers to the formation of skin appendages?
A. Morphogenesis
B. Differentiation
C. Specification
D. Biogenesis
A. Morphogenesis
How is Phaeomelanin formed?
A. Inhibition of the enzyme Tyrosinase
B. Addition of Cysteine to a Tyrosine
C. Removal of 3,4 – dihydroxyphenylalanine (DOPA)
D. Addition of Cysteine to dopaquinone
D. Addition of Cysteine to dopaquinone
Which of the following explains how the sympathetic nervous system regulates heat
conduction of the skin?
A. By increasing blood flow to the skin
B. By causing vasodilation of arterioles
C. By controlling vasoconstriction of arterioles
D. By increasing sweating
C. By controlling vasoconstriction of arterioles
Which of the following explains why the rate of heat loss by conduction of air
depends on air temperature relative to skin temperature?
A. Cold air absorbs heat more efficiently
B. Heat is only lost if the air is cooler than the skin
C. Warm air can retain heat from the body
D. Air molecules are always in motion
B. Heat is only lost if the air is cooler than the skin
f a person is sitting in a room with a temperature higher than their skin temperature,
what mechanism will primarily help them lose heat?
A. Radiation
B. Conduction
C. Evaporation
D. Convection
C. Evaporation
Which of the following statements correctly describes the keratinization of hair?
A. Keratinized hair cells are sloughed continuously.
B. Keratinized hair cells are identical.
C. Keratinized hair cells do not differ in structure and function.
D. Keratinized hair cells are tightly attached to one another.
D. Keratinized hair cells are tightly attached to one another.
Given the effectiveness of the skin as a controlled “heat radiator” system, which
factor is deemed to be the most effective mechanism for heat transfer from the body
core to the skin?
A. skin thickness
B. skin surface area
C. blood flow rate
D. state of hydration
C. blood flow rate
Which cellular component of the skin conducts heat only one third as readily as
other tissues?
A. Keratinocytes
B. Melanocytes
C. Myocytes
D. Adipocytes
D. Adipocytes
Which type of hair covers much of the fetus and is usually shed before birth?
A. Vellus hair
B. Lanugo hair
C. Terminal hair
D. Indeterminate hair
B. Lanugo hair
If a forensic investigator finds a hair that is round and straight, from which group did
the hair most likely have originated?
A. Asians
B. Caucasians
C. Blacks
D. Albinos
A. Asians
Which of the following primarily determines the color of human skin?
A. Hemoglobin
B. Melanin
C. Collagen
D. Keratin
B. Melanin
Which of the following structures is absent in the dermis of thick skin?
A. Blood vessels
B. Hair follicles
C. Nerve endings
D. Connective tissue
B. Hair follicles
Which of the following is a primary method of heat production in the body?
A. Vasodilatation
B. Shivering
C. Sweating
D. Convection
B. Shivering
A marathon runner suddenly collapses on a very hot day, showing signs of heat
exhaustion. Which of the following mechanisms most likely failed to regulate the
patient’s body temperature?
A. Heat conservation through vasoconstriction.
B. Shivering thermogenesis
C. Sweating and evaporative cooling.
D. Increased metabolic rate for heat production
C. Sweating and evaporative cooling.
Which of the following provides immune function in the skin?
A. Keratinocytes
B. Adipocytes
C. Melanocytes
D. Langerhans cells
D. Langerhans cells
Matrix metalloproteinases (MMPs) are responsible for breaking down collagen
fibers. If MMP activity is high and abnormal collagen fragments accumulate, what
does this suggest in the balance between tissue collagen synthesis and
degradation?
A. Collagen synthesis is outpacing degradation, leading to excessive collagen
buildup.
B. Collagen degradation is outpacing synthesis, resulting in tissue instability.
C. Both collagen biosynthesis and degradation are in complete homeostatic balance
D. Both collagen biosynthesis and degradation have no direct impact in tissue
stability
B. Collagen degradation is outpacing synthesis, resulting in tissue instability.
Which among the following is the embryogenic origin of the epidermis?
A. Endoderm
B. Mesoderm
C. Mesenchyme
D. Ectoderm
D. Ectoderm
Which of the following is not a constituent of sweat?
A. Albumin
B. Sodium
C. Urea
D. Potassium
A. Albumin
Which neurotransmitter is released by the sympathetic neurons to activate the
sweat glands?
A. Acetlycholine
B. Norepinephrine
C. Dopamine
D. Serotonin
A. Acetlycholine
Which of the following best describes the action of pyrogens on the body’s
temperature?
A. Inhibits the enzyme, Cyclooxygenase
B. Activates receptors in brown fat
C. Increases the set-point temperature
D. Represses internal thermogenesis
C. Increases the set-point temperature
Which of the following best explains the role of collagen’s triple helix structure in
connective tissues?
A. Allows collagen flexibility and easy degradation by enzymes.
B. It makes collagen hydrophobic, rendering it waterproof in tissues.
C. Prevents collagen binding to other proteins, maintaining tissue stability.
D. Provides tensile strength and resistance to stretching forces.
B. It makes collagen hydrophobic, rendering it waterproof in tissues.
