Basement Membrane & Connective Tissue [Practice MC Questions]

Which is the correct order of the three layers of skin (superficial → deep)?

A) Basement membrane → epithelium → connective tissue

B) Epithelium → basement membrane → dense irregular CT

C) Dense irregular CT → basement membrane → epithelium

D) Basement membrane → dense irregular CT → epithelium

E) Epithelium → connective tissue → basement membrane

B

True/False: The basement membrane is a specialized extracellular matrix layer attaching epithelium to connective tissue.

True

Statement 1: The BM resists shearing forces and maintains tissue integrity.

Statement 2: The BM regulates epithelial-mesenchymal interactions.

A) Both True

B) Both False

C) 1 True, 2 False

D) 1 False, 2 True

A

Which of the following is not a function of the basement membrane?

A) Provides resiliency against shearing

B) Maintains tissue architecture during repair

C) Promotes epithelial cell apoptosis

D) Regulates epithelial-mesenchymal interactions

E) Maintains structural integrity

C

Which of the following are protein components of the BM?

A) Collagen XVII, KRT5/14, Plectin

B) Laminin, Myosin, Elastin

C) Fibronectin, Collagen I, Actin

D) Hemoglobin, Fibrillin, Tropomyosin

E) Elastin, Keratohyalin, Perlecan

A

True/False: All tissues have the three layers in the basement membrane.

False

Which tissues specifically contain all three BM layers (lucida, densa, reticularis)?

A) Skin mucosa

B) Oral mucosa only

C) Muscle tissue

D) Cartilage

E) Bone

A

The lamina lucida is located:

A) Deepest, attached to connective tissue

B) Beneath the epithelium, as a clear buffer zone

C) In the dermis

D) Between lamina densa and lamina reticularis

E) Absent in the skin

B

Which layer of the BM is dense and closer to connective tissue?

A) Lamina lucida

B) Lamina densa

C) Lamina reticularis

D) Basal lamina

E) Dermis

B

True/False: The lamina reticularis binds the BM to connective tissue below.

True

The basal lamina is defined as:

A) Lamina densa only

B) Lamina lucida + lamina densa

C) Lamina densa + lamina reticularis

D) Reticular fibers of connective tissue

E) None of the above

B

Anchoring filaments in the lamina lucida include:

A) Collagen I, Collagen III, Fibronectin

B) Laminin-332, Collagen XVII, BP180

C) KRT5, KRT14, Plectin

D) Fibronectin, Elastin, Tropomyosin

E) Actin, Myosin, Desmoplakin

B

Which components are part of the lamina densa?

A) Collagen IV, Collagen VII, Nidogen, Perlecan

B) Collagen I, Collagen III, Fibronectin

C) Laminin-332, BP230, BP180

D) Tropocollagen, Myosin, Keratin

E) Actin, Integrin, Fibrillin

A

Collagen VII is important because it:

A) Forms triple helices

B) Binds collagen below and above the BM

C) Synthesizes elastic fibers

D) Anchors keratinocytes to BM directly

E) Is present only in muscle tissue

B

Which are components of the lamina reticularis?

A) Collagen I, Collagen III, Elastic fibers, Fibronectin

B) Collagen IV, Laminin, Nidogen

C) Keratin 5 and 14, Plectin

D) Hyaluronic acid, Chondroitin sulfate

E) BP230, BP180

A

Which type of EB is caused by mutations in KRT5, KRT14, or plectin?

A) Junctional EB

B) Dystrophic EB

C) Simplex EB

D) Kindler syndrome

E) Acquired EB

C

True/False: Junctional EB involves separation in the lamina lucida.

True

Which proteins are mutated in junctional EB?

A) Collagen XVII, Integrin α6β6, Laminin-332

B) Collagen I, III, V

C) KRT5, KRT14

D) Collagen VII

E) Fibrillin, Elastin

A

Statement 1: Dystrophic EB is associated with collagen VII mutation.

Statement 2: Patients with dystrophic EB have increased oral cancer risk.

A) Both True

B) Both False

C) 1 True, 2 False

D) 1 False, 2 True

A

Which EB subtype involves separation at the very base of the BM, causing all layers to detach?

A) Simplex EB

B) Junctional EB

C) Dystrophic EB

D) Kindler syndrome

E) None of the above

D

True/False: Transgenic stem cells have been used as therapy for EB by regenerating human epidermis.

True

Dense irregular connective tissue primarily composes:

A) Dermis of skin

B) Basement membrane

C) Reticular fibers of lymph nodes

D) Endothelium of blood vessels

E) Bone

A

True/False: Dense irregular CT provides structural support, nutrient exchange, fat storage, and immune defense.

True

In the head and neck, dense irregular CT derives from:

A) Mesoderm

B) Neural crest (ectomesenchyme)

C) Endoderm

D) Epidermis

E) Fibroblasts only

B

Which of the following are fixed cells of dense irregular CT?

A) Fibroblasts, Myofibroblasts, Adipocytes, Mast cells

B) Neutrophils, Eosinophils, Basophils

C) Plasma cells, Monocytes, Lymphocytes

D) Keratinocytes, Melanocytes, Merkel cells

E) Osteoblasts, Osteoclasts, Chondrocytes

A

Which cells are transient in dense irregular CT?

A) Fibroblasts and adipocytes

B) Neutrophils, eosinophils, basophils, lymphocytes

C) Mast cells and pericytes

D) Myofibroblasts only

E) Keratinocytes and Langerhans cells

B

True/False: Fibroblasts are the most abundant and least specialized cells of CT.

True

Which fibers are synthesized by fibroblasts?

A) Collagen I, Elastic, Reticular

B) Collagen IV, Elastin, Perlecan

C) Collagen VII, Actin, Keratin

D) Fibronectin, Myosin, Laminin

E) Tropomyosin, Desmin, Collagen IX

A

Which type of collagen is most abundant in the body?

A) Type I

B) Type II

C) Type III

D) Type IV

E) Type V

A

Which collagen type is found in cartilage?

A) I

B) II

C) III

D) IV

E) V

B

True/False: Collagen type III supports hollow organs and is common around blood vessels.

True

Which collagen type is primarily in the basement membrane?

A) I

B) II

C) III

D) IV

E) V

D

Which collagen type is required for fibrillation of types I and III?

A) I

B) II

C) III

D) IV

E) V

E

Statement 1: Fibrillar collagens include Type I and III.

Statement 2: Type V is non-fibrillar but required for fiber formation.

A) Both True

B) Both False

C) 1 True, 2 False

D) 1 False, 2 True

A

Which condition is caused by Vitamin C deficiency leading to defective collagen I?

A) Marfan syndrome

B) Ehlers-Danlos

C) Scurvy

D) Epidermolysis bullosa

E) Cutis laxa

C

Ehlers-Danlos syndrome results from defects in:

A) Collagen I, III, or V and processing proteins

B) Collagen II and elastin

C) Laminin-332 only

D) Integrins and hemidesmosomes

E) Keratin 5 and 14

A

Elastic fibers are composed of:

A) Collagen and laminin

B) Elastin and fibrillin

C) Hyaluronic acid and fibronectin

D) Actin and myosin

E) Keratin and tropomyosin

B

True/False: Cutis laxa is caused by mutations in fibrillin.

False

Which syndrome involves tall stature, long limbs, flexible joints, and aortic rupture risk?

A) Ehlers-Danlos

B) Cutis laxa

C) Marfan syndrome

D) Scurvy

E) Junctional EB

C

Which mutation causes sagging, wrinkled, non-stretchable skin?

A) Collagen VII

B) Elastin

C) Fibrillin

D) Laminin

E) Keratin

B

Which ECM component cushions tissues due to water-binding capacity?

A) GAGs

B) Proteoglycans

C) Adhesive glycoproteins

D) Fibroblasts

E) Collagen

A

Which of the following is a GAG?

A) Hyaluronic acid

B) Heparin

C) Chondroitin sulfate

D) All of the above

E) A and B only

D

True/False: Proteoglycans are larges ECM macromolecules containing GAGs.

True

Which are adhesive glycoproteins in the ECM?

A) Fibronectin, Laminin

B) Collagen I, III

C) Elastin, Fibrillin

D) BP180, BP230

E) Tropomyosin, Desmin

A

Which are the three main components of connective tissue?

A) Cells, fibers, ground substance

B) Epithelium, BM, CT

C) GAGs, proteoglycans, glycoproteins

D) Keratin, collagen, actin

E) Dermis, epidermis, hypodermis

A

Which statement reflects the clinical importance of ECM?

A) ECM plays no role in cancer

B) ECM proteins stimulate angiogenesis

C) ECM cannot remodel after injury

D) ECM is associated with benign cancers

E) ECM inhibits wound healing

B

True/False: ECM degradation can occur in both physiological and pathological conditions.

True

Which is a physiological cause of ECM degradation?

A) Angiogenesis

B) Embryonic development

C) Wound healing

D) Bone remodeling

E) All of the above

E

Which are pathological causes of ECM degradation?

A) Inflammatory diseases

B) Cancer metastasis

C) Both A and B

D) Neither A nor B

E) Vitamin C deficiency

C

Matrix metalloproteinases (MMPs):

A) Are zinc-dependent proteases

B) Break down ECM

C) Aid in tissue remodeling and repair

D) Are regulated by tissue inhibitors (TIMPs)

E) All of the above

E