Cell Types and Tissue Structure

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Questions and Answers

What is the primary function of simple squamous epithelia?

Absorption and secretion

Diffusion and filtration (correct)

Protection from abrasion

Storage of substances

Which mechanism is responsible for the production of gametes?

Cell Differentiation

Meiosis (correct)

Binary Fission

Mitosis

Which type of cells are categorized as gametes?

Nerve cells

Skin cells

Muscle cells

Eggs and Sperm (correct)

Which type of connective tissue is characterized by loosely arranged collagen and elastin fibers?

Loose connective tissue Signup and view all the answers

Where can stratified squamous epithelia typically be found?

Esophagus and skin Signup and view all the answers

What is a significant characteristic of dense connective tissue?

It has closely packed collagen or elastic fibers Signup and view all the answers

What bodily function is NOT a characteristic of serous membranes?

Protection against infection Signup and view all the answers

What type of connective tissue primarily performs the function of muscle-to-bone connections?

Tendons Signup and view all the answers

What role do cell adhesion molecules (CAMs) play in tissues?

They bind epithelial cells to each other and to extracellular materials. Signup and view all the answers

Which type of epithelial tissue is specialized for absorption and secretion in glandular functions?

Simple cuboidal epithelium Signup and view all the answers

What type of cells are found in the apical surface of keratinized stratified squamous epithelium?

Squamous cells Signup and view all the answers

Which of the following connective tissues is poorly vascularized and tends to heal very poorly?

Dense connective tissue Signup and view all the answers

What is the function of a hemidesmosome in epithelial tissue?

It attaches the deepest epithelial cells to the basal lamina. Signup and view all the answers

What is the primary secretion produced by goblet cells?

Mucous Signup and view all the answers

Which part of the basement membrane contains bundles of coarse reticular fibers?

Lamina densa. Signup and view all the answers

What role do fibroblasts play in connective tissue?

They secrete extracellular matrix proteins Signup and view all the answers

Which characteristic is NOT shared by all epithelial tissues?

High vascularity Signup and view all the answers

Which connective tissue type primarily forms the structural framework of organs and is highly vascularized?

Loose connective tissue Signup and view all the answers

How does the basement membrane contribute to tissue function?

By acting as a selective barrier that restricts diffusion. Signup and view all the answers

What type of epithelial lining is found in body cavities that are open to the outside?

Mucous membranes Signup and view all the answers

Which connective tissue is responsible for the continuous circulation of extracellular fluid?

Lymph Signup and view all the answers

What is the primary structural component of intermediate filaments in epithelial cells?

Keratin. Signup and view all the answers

Why are desmosomes typically found only in certain locations on epithelial cells?

They are specialized for areas experiencing mechanical stress. Signup and view all the answers

What is edema in the context of connective tissue?

A swelling caused by fluid release from blood vessels Signup and view all the answers

What is the lamina lucida of the basement membrane primarily composed of?

Glycoproteins and fine protein filaments. Signup and view all the answers

Which of the following best describes the relationship between the epithelium and the basement membrane?

The basement membrane supports and anchors the epithelium. Signup and view all the answers

What type of cells are found in lacunae in cartilage?

Chondrocytes Signup and view all the answers

What is the function of cartilage in the body?

It cushions the ends of long bones. Signup and view all the answers

What is a significant difference between cartilage and bone?

Cartilage is avascular; bone is vascularized. Signup and view all the answers

What is found surrounding all types of cartilage?

Perichondrium Signup and view all the answers

What major component makes up approximately 2/3rds of the bone matrix?

Calcium salts Signup and view all the answers

What type of growth occurs when cartilage expands from within?

Interstitial growth Signup and view all the answers

Which type of connective tissue serves as a cushioning agent in joints?

Cartilage Signup and view all the answers

Which cells are responsible for the growth and maintenance of bone?

Osteoblasts and osteoclasts Signup and view all the answers

Study Notes

Two fundamental kinds of cells in the body

Gametes (eggs and sperm) are produced by cell division called meiosis
Somatic cells are found in tissues and organs

Structures that Connect epithelial cells to each other

Intermediate filaments of cytoskeleton, primarily composed of keratin, provide structural support
Cell adhesion molecules (CAMs) are transmembrane proteins that bind to each other and extracellular materials, creating connections between cell membranes
Desmosomes are specialized junctions that increase the resistance of tissues to mechanical stress
Tight junctions form a tight seal between adjacent cell membranes, limiting passage of substances

Basement Membrane

A complex structure produced by the basal surface of the epithelium and the underlying connective tissue
The clear layer, or lamina lucida, contains glycoproteins and a network of fine protein filaments
the dense layer, or lamina densa, contains bundles of coarse reticular fibers, providing strength
Acts as a filter, restricting diffusion between adjacent tissues and the epithelium

Epithelial Tissue

Specialized for diffusion, filtration and secretion
Types:
- Simple Squamous Epithelia
- Stratified Squamous Epithelia
- Simple Cuboidal Epithelia
- Simple Columnar Epithelia
- Pseudostratified Columnar Epithelia
- Transitional Epithelia

Simple Squamous Epithelia

Found in the lining of blood vessels, alveoli of the lungs, capillary walls, and endocardium
Line body cavities that are not open to the outside, forming part of serous membranes
Functions:
- Reduce friction
- Regulate fluid composition, including permeability, absorption, and secretion
- Transport across simple epithelia includes passive transport (diffusion) and active transport (requires energy)

Stratified Squamous Epithelia

Most common stratified epithelia
Specialized for protection, found in areas subject to abrasion
Lines the mouth, esophagus, and outer layer of skin (keratinized)
Apical surface contains squamous cells, while deeper cells may be cuboidal or columnar
Basal cells undergo mitosis to replace surface cells that are rubbed away

Simple Cuboidal Epithelia

Specialized for absorption and secretion
Found in glands and ducts, such as the thyroid gland and kidney tubules

Simple Columnar Epithelia

Specialized for absorption and secretion
Lines the digestive tract from the stomach to the anus
Contains goblet cells that produce mucous

Pseudostratified Columnar Epithelia

Specialized for secretion, protection, and movement of mucous
Lines the trachea and upper respiratory tract
Contains cilia for movement of mucous

Transitional Epithelia

Specialized for stretching and distention
Found in the lining of the urinary bladder and ureters

Connective Tissue

Characterized by an intricate extracellular matrix containing collagen fibers and elastin fibers
Can be vascular (contains blood vessels) or avascular (lacks blood vessels)
Six general categories:
- Loose Connective Tissue
- Dense Connective Tissue
- Cartilage
- Bone
- Blood
- Lymph

Loose Connective Tissue

Contains both collagen and elastin fibers, loosely arranged
Forms the basement membrane for epithelia tissue and mucous membranes
Can swell with fluid release from the bloodstream, resulting in edema
Types:
- Areolar Connective Tissue
- Adipose Tissue
- Reticular Connective Tissue

Dense Connective Tissue

Contains mostly collagen or elastic fibers in its matrix, closely packed
Types:
- Dense Regular Connective Tissue: found in tendons and ligaments
- Dense Irregular Connective Tissue: found in dermis, visceral organ capsules, perichondrium, periosteum
- Elastic Connective Tissue: found in elastic ligaments between vertebrae and walls of large blood vessels

Fluid Connective Tissue

Includes blood and lymph
Contains plasma, a fluid extracellular matrix with dissolved proteins and other substances
Blood cells:
- Red blood cells (erythrocytes) carry oxygen
- White blood cells (leukocytes) fight infection
- Platelets (thrombocytes) involved in blood clotting

Supporting Connective Tissue

Provides structural support and protection
Types:
- Cartilage:
  - Composed of chondrocytes in cavities called lacunae
  - Matrix contains collagen and a gel-like substance
  - Avascular, receives nutrients by diffusion
  - Types:
    - Hyaline Cartilage: found in costal cartilage, articular cartilage, nose and trachea
    - Elastic Cartilage: found in epiglottis and external ear
    - Fibrocartilage: found in intervertebral disks and pubic symphysis
- Bone:
  - Matrix contains calcium salts, collagen fibers, and bone cells
  - Vascular, receives nutrients through blood vessels
  - Site of hematopoiesis (blood cell production)

Membranes

Thin sheet-like structures composed of epithelial tissue and underlying connective tissue
Types:
- Mucous Membranes: line body cavities open to the outside
- Serous Membranes: line body cavities that are not open to the outside
- Cutaneous Membranes: outermost layer of skin
- Synovial Membranes: line joint cavities

Fascia

Layers and wrappings of connective tissues that support and surround organs
Types:
- Superficial Fascia: located beneath the skin
- Deep Fascia: surrounds muscle and other organs
- Visceral Fascia: surrounds individual organs
Helps organize and compartmentalize different body structures

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Description

This quiz explores the two fundamental kinds of cells in the body, namely gametes and somatic cells, and their roles. It also covers the structures that connect epithelial cells, including intermediate filaments, cell adhesion molecules, desmosomes, and tight junctions, as well as the composition of the basement membrane.