Epithelial Cell Polarity Quiz

Questions and Answers

What type of Ehlers Danlos syndrome is caused by mutations in Type III collagen?

Type I

Type IV (correct)

Type II

Type III

What is the primary function of elastic fibers in connective tissue?

Confer elasticity (correct)

Provide strength to the tissues

Facilitate cell migration

Store energy

What is the role of fibrillin in relation to elastic fibers?

It enhances tensile strength

It provides hydration to the fibers

It acts as a structural component (correct)

It degrades damaged fibers

Which of the following conditions results from a genetic defect in fibrillin?

Marfan’s syndrome Signup and view all the answers

What is the main composition of the ground substance in connective tissue?

Proteoglycans and hyaluronan Signup and view all the answers

How does the structure of elastin contribute to its elasticity?

Hydrophobic segments coil on themselves Signup and view all the answers

What serious condition can result from defects in elastic fibers due to Marfan's syndrome?

Aneurysm or rupture of the aorta Signup and view all the answers

What molecules are primarily embedded in the gel-like matrix of the ground substance?

Proteoglycans and hyaluronan Signup and view all the answers

What is the main characteristic of epithelial cell polarity?

Epithelial cell plasma membranes are differentiated into distinct domains. Signup and view all the answers

What is the function of the basal lamina in epithelial cells?

To assist in the attachment of the epithelium to connective tissue. Signup and view all the answers

Which of the following structures are formed on the basal plasma membrane of epithelial cells?

Adherens junctions and hemidesmosomes. Signup and view all the answers

Which of the following best describes the role of tight junctions in epithelial cells?

They prevent intercellular passage of fluids and molecules. Signup and view all the answers

Where do the lateral surfaces of epithelial cells primarily face?

Adjacent epithelial cells. Signup and view all the answers

What is a key function of the apical domain in epithelial cells?

Regulating transport and absorption. Signup and view all the answers

How do epithelial cells primarily maintain their structural integrity?

Through the formation of tight junctions. Signup and view all the answers

What defines the basal surface of epithelial cells?

It is oriented toward the underlying connective tissue. Signup and view all the answers

What is the primary component of connective tissue that differentiates it from epithelium?

Extracellular matrix Signup and view all the answers

Which type of collagen is the most abundant in connective tissue proper?

Type I collagen Signup and view all the answers

What aspect of connective tissue is primarily provided by collagen fibers?

Tensile strength Signup and view all the answers

What is the primary role of fibroblasts in connective tissue?

Production of fibers and ground substance Signup and view all the answers

Which statement regarding the extracellular matrix of connective tissue is true?

It occupies more space than the cellular component. Signup and view all the answers

What characteristic distinguishes elastic fibers in connective tissue?

They confer elasticity to the tissue. Signup and view all the answers

How many different types of collagen are there in total?

More than 20 Signup and view all the answers

What is the visible form of Type I collagen in histological sections?

Large bundles of fibers Signup and view all the answers

What are the repeating units called that make up the ordered arrangement of contractile proteins in muscle fibers?

Sarcomeres Signup and view all the answers

What type of tissue surrounds each muscle fiber?

Basal lamina and loose connective tissue Signup and view all the answers

Where are satellite cells located in relation to muscle fibers?

Inside the basal lamina Signup and view all the answers

What can activate satellite cells within muscle tissue?

Muscle damage and intense exercise Signup and view all the answers

What characterizes cardiac muscle compared to skeletal muscle?

Provides regular, powerful contractions Signup and view all the answers

Which structures run alongside muscle fibers within the connective tissue?

Nerve branches and small blood vessels Signup and view all the answers

What happens to satellite cells after muscle injury?

They can proliferate and assist in muscle repair Signup and view all the answers

In which locations is cardiac muscle found?

Only in the heart and pulmonary veins Signup and view all the answers

What is the primary role of mast cells in the inflammatory response?

To initiate the inflammatory response and increase vascular permeability Signup and view all the answers

Which component is not found in the secretory granules of mast cells?

Antibodies Signup and view all the answers

What triggers mast cell degranulation in response to allergens?

Binding of IgE antibodies Signup and view all the answers

What is the primary function of plasma cells?

Differentiate from antigen-stimulated B lymphocytes to secrete antibodies Signup and view all the answers

What is a key feature of white blood cells in connective tissue?

They originate in bone marrow and circulate in blood Signup and view all the answers

Which white blood cell differentiates into macrophages in tissues?

Monocytes Signup and view all the answers

Which of the following is NOT a type of white blood cell mentioned?

Basophils Signup and view all the answers

During chronic inflammation, what happens to plasma cell numbers?

Increase considerably Signup and view all the answers

Study Notes

Characteristics of Epithelia

Epithelial cells exhibit polarity with distinct apical, lateral, and basal surfaces, facilitating directional transport.
The basal surface interacts with connective tissue and is anchored to the basal lamina, a glycoprotein layer.
Basal surface specializations include adherens junctions and hemidesmosomes for enhanced attachment to the extracellular matrix.

Epithelial Cell Junctions

Lateral surfaces host intercellular junctions; the tight junction (zonula occludens) is crucial for sealing gaps between cells, preventing the passage of fluids and molecules.

Extracellular Matrix in Connective Tissue

In connective tissue, extracellular matrix predominates over cells, composed of fibers and ground substance.
Collagen, particularly Type I and Type III, provides tensile strength; Type I collagen is the most abundant protein in the body.
Mutations in Type III collagen are associated with Ehlers-Danlos syndrome, impacting organ structural integrity.

Fiber Types in Connective Tissue

Elastic fibers, synthesized by fibroblasts and smooth muscle, provide elasticity; their formation involves tropoelastin and the glycoprotein fibrillin.
Marfan's syndrome results from fibrillin defects, leading to issues with elastic fibers, notably in the aorta.

Ground Substance Composition

Ground substance consists primarily of proteoglycans and hyaluronan, facilitating cell migration and differentiation through adhesive glycoproteins.

Mast Cells

Derived from bone marrow stem cells, mast cells are found near blood vessels and release histamine and other mediators during inflammatory responses.
They play a key role in allergic reactions, including anaphylaxis, by increasing vascular permeability and causing edema.

Plasma Cells

Plasma cells develop from activated B lymphocytes in connective tissue and are responsible for antibody secretion, especially during chronic inflammation.

White Blood Cells in Connective Tissue

Leukocytes, including neutrophils and macrophages, originate from bone marrow, circulating in blood and migrating into tissues to perform immune functions.
The immune response involves mechanisms that allow these cells to exit blood vessels and infiltrate surrounding tissues.

Muscle Cell Structure

Each muscle fiber features a sheath with a basal lamina and associated connective tissue, housing small blood vessels and nerves.
Satellite cells, which possess stem cell-like qualities, can be activated for muscle repair after injury or intense exercise.

Cardiac Muscle Characteristics

Cardiac muscle is involuntary, providing consistent, strong contractions and is exclusively found in the heart and pulmonary veins.
It forms the primary structure of the heart, essential for its pumping function.

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Description

Test your understanding of epithelial cell polarity and characteristics. This quiz covers the structural features of epithelial cells, including their organelle distribution and specialized membrane domains. Challenge your knowledge on the essential concepts of epithelial tissue types.