Biology - Tissues in Human (Practice Flashcards)

A comprehensive set of practice flashcards covering tissue types, epithelial tissue structure and modifications, glands, and connective tissue including bone and cartilage.

What are the four basic tissue types?

Epithelial, Connective, Muscular, and Nervous tissues.

what statement is true about tissue cells

What is tissue?

A group of similar cells along with intercellular substances that perform a specific function.

On what basis are tissues classified into four types?

By function and structure:

1. Epithelium,

2. Connective,

3. Muscular,

4. Nervous tissues.

What is the primary function of epithelial tissue?

Covering and protection.

What is the primary function of connective tissue?

To connect structures, provide support, and transport substances.

What is the main function of muscular tissue?

Contraction and locomotion.

What is the main function of nervous tissue?

To generate and conduct nerve impulses.

What is the basement membrane?

A thin, non-living acellular layer between epithelium and connective tissue that is highly permeable.

Which tissue has the highest regenerative power and which has the least?

Epithelial tissue has the highest regenerative power; nervous tissue has the least.

Do epithelial cells have significant intercellular spaces?

No; they are compact with little intercellular space.

Do epithelial tissues contain blood or lymph capillaries?

Where does nourishment come from?

No; they lack blood and lymph capillaries due to very little intercellular spaces

nourishment comes from underlying connective tissue.

From where do epithelial tissues obtain nutrition?

From the underlying connective tissue.

What is the role of the basement membrane in epithelium?

A permeable, thin, non-living layer separating epithelium from connective tissue.

Epithelial tissues have a free surface which face either a body fluid or the outside environment, it therefore provides what?

A lining for some parts of the body

What are microvilli and where are they found?

Tiny projections increasing surface area for absorption and secretion; found in the wall of the intestine, gall bladder, and proximal convoluted tubule of the nephron.

List the modifications of epithelial tissues

1. Microvilli - increases SA

2. Cilia - helps in movement and locomotion

3. Stereocilia - increases Surface area

The basement membrane in epithelial tissue is made from dead cells, T/F?

True

What are cilia and what do they do?

Motile projections that move particles or mucus in a single direction; found in trachea, bronchi, bronchioles, fallopian tubes, uterus, etc.

What are stereocilia?

Conical shape , non-motile projections that increase surface area; found in epididymis and vas deferens (male reproductive anatomy)

in Simple Epithelium tissues:

How many layers of cells?

They all rest on what membrane?

A single layer of cells;

all rest on the basement membrane;

lines body cavities, ducts, and tubes.

4 types of simple epithelium:

1. Simple squamous

2. Simple cuboidal

3. Simple columnar

4. Pseudostratified (appears stratified (2 or more layers) but isn’t)

Describe Simple Squamous Epithelium and where it is found.

A single layer of flattened cells; forms diffusion/filtration membranes; lines walls of blood vessels and alveoli; Bowman's capsule; pleura; endothelium/mesothelium.

What is compound epithelium tissue and what is its primary function?

Compound epithelium tissue consists of more than one layer of cells, meaning it is multi-layered. Its primary function is protection against mechanical and chemical stress, and it has a limited role in absorption and secretion.

What are the types of compound (stratified) epithelium?

The types of compound (stratified) epithelium include:

1. Non-stretchable Epithelium:
   • Stratified Squamous Epithelium: Provides protection, found in the outer layer of skin and lining of mouth and esophagus.
   • Stratified Cuboidal Epithelium: Offers protection, found in the ducts of sweat glands and mammary glands.
   • Stratified Columnar Epithelium: Provides protection and some secretion, found in parts of the male urethra and some large ducts.
2. Stretchable Epithelium:
   • Transitional Epithelium: Specialized to permit distension and stretch, found in the urinary bladder, ureters, and part of the urethra.

What are the types of compound (stratified) epithelium?

The types of compound (stratified) epithelium include:

1. Non-stretchable Epithelium:
   • Stratified Squamous Epithelium: Provides protection, found in the outer layer of skin and lining of mouth and esophagus.
   • Stratified Cuboidal Epithelium: Offers protection, found in the ducts of sweat glands and mammary glands.
   • Stratified Columnar Epithelium: Provides protection and some secretion, found in parts of the male urethra and some large ducts.
2. Stretchable Epithelium:
   • Transitional Epithelium: Specialized to permit distension and stretch, found in the urinary bladder, ureters, and part of the urethra.

Which simple tissue type is associated with filtration and diffusion?

What simple tissue covers the the lining of the alveoli?

the following have simple squamous tissue:

Endothelium, Mesothelium, Endocardium, Pleura

what surfaces do these tissues cover?

Endothelium lines blood and lymph vessels;

Mesothelium lines body cavities (coelom);

Endocardium lines the inner heart.

Pleura covers the lungs

Describe Simple Cuboidal Epithelium and where it is found and function .

A single layer of cube-like cells;

lines ducts of glands and tubules of nephrons;

functions in secretion and absorption (e.g., sweat glands, thyroid vesicles).

What are the cuboidal modifications?

“Brush-bordered cuboidal” (the name of it when it has microvilli). It is found in the PCT;

Ciliated cuboidal epithelium (when cilia is present on the free end)

Found in collecting ducts;

Ciliates cuboidal epithelium aka “germinal epithelium” bc it is found in the gonads (testes and ovaries) and divide to form egg and sperm cells

What is Germinal Epithelium?

Cuboidal epithelium in gonads that divides to form eggs and sperm.

Describe Simple Columnar Epithelium and its function.

A single layer of tall columnar cells;

nuclei at the base and is elongated;

functions in absorption and secretion.

What are the modifications of Simple Columnar Epithelium?

Brush-bordered (microvilli);

glandular - unicellular and mucus secreting (goblet cells);

glandular brush-bordered; has microvilli and goblet cells

ciliated; has cilia

stereociliated epithelium; when stereocilia are present

What is Pseudostratified Epithelium?

Columnar epithelium with nuclei at different levels

, appearing bilayered though it is unilayered;

Contains long and short cells

contains cilia and goblet cells.

Where is Pseudostratified Epithelium commonly found?

Nasopharynx, trachea, bronchi, bronchioles, and respiratory epithelium of nasal chambers.

What is Compound Epithelium?

Multilayered epithelium that provides protection against chemical and mechanical stress.

What is Transitional Epithelium (Urothelium) and where is it found?

Stretchable epithelium;

basement membrane becomes invisible on stretch;

4–6 layers when relaxed;

lines renal pelvis, ureter, urinary bladder.

What are the non-stretchable types of stratified epithelium?

Stratified Squamous, Stratified Cuboidal, Stratified Columnar.

What is Stratified Squamous Epithelium and its keratinized vs non-keratinized forms?

Multi-layered protective epithelium;

Keratinized: has keratin and dead cells. NON NUCLEATED

Non-keratinized: remains nucleated and living. NUCLEATED

Role of cell junctions

Structural and functional links between individual cells

What are Desmosomes, Tight Junctions, Gap Junctions, and Interdigitations?

types of cell junctions

Interdigitations are a type of cell junction, describe them

Finger like processes of plasma membrane which enter into cytoplasm of adjacent cells.

mainly found in stretchable/transitional

tight junctions are a type of cell junction, describe their role

Stops substances from leaking across a tissue

Desmosomes are a type of cell junction, describe their role

Act as cement to keep neighbouring cells together

Provides mechanical support

Mostly found in non-stretchable epithelium

Gap junctions are a type of cell junction, describe their role

Facilitate the cells to communicate with each other

Rapid transfer of ions, small molecules and sometimes bug molecules

What are Glands and their basic composition?

Cells or groups of cells that secrete chemical substances; all glands are composed of epithelial tissue.

What are unicellular vs multicellular glands?

Unicellular: isolated secretory cells (e.g., goblet cells); Multicellular: clusters of secretory cells (e.g., salivary glands).

On the basis of secretion, what are endocrine, exocrine, and heterocrine glands?

Endocrine glands secrete into blood (no ducts); Exocrine glands have ducts (salivary, gastric, etc.); Heterocrine glands have both endocrine and exocrine parts (pancreas, gonads).

What is connective tissue and its general role?

A tissue that connects and supports; cells secrete fibres (collagen, elastin, reticulin) which provide strength, elasticity, and flexibility; also protects and replaces tissues.

What are the main types of connective tissue by arrangement?

Loose (Areolar, Adipose); Dense (Regular and Irregular); Specialized (Skeletal, Fluid). Also cartilage and bone as supporting tissues.

What are the key components of connective tissue?

Cells (fibroblasts, macrophages, mast cells, adipocytes) and extracellular fibres (collagen, elastic, reticular) in a matrix.

What is Areolar connective tissue and its function?

A widely distributed loose connective tissue with loose matrix; provides structural support and flexibility to surrounding tissues.

What is Adipose tissue and how is it classified?

Loose connective tissue specialized for fat storage; White fat (monolocular adipocytes) and Brown fat (multilocular adipocytes); white stores energy, brown generates heat.

What is Dense Regular connective tissue and Dense Irregular connective tissue?

Dense Regular: fibres arranged in parallel (tendons, ligaments). Dense Irregular: fibres in mesh (skin, pericardium).

What is Skeletal Connective Tissue?

Includes cartilage and bone; matrix is solid/mineralised and provides structural support.

What are chondroblasts, chondrocytes, lacunae, and chondroclasts?

Chondroblasts produce cartilage and divide to form chondrocytes; chondrocytes reside in lacunae; chondroclasts destroy cartilage.

What are the types of cartilage?

Hyaline, Elastic, and Fibrous cartilage.

What are osteoblasts, osteocytes, and osteoclasts?

Osteoblasts form bone; become osteocytes; osteocytes reside in lacunae; Osteoclasts destroy bone.

What is ossification?

The process of bone formation.

What are Haversian canals and lamellae?

Structural features of compact bone: Haversian canals run longitudinally containing vessels; lamellae are concentric rings around canals.

What are the general features and main functions of bone?

Features: highly vascular, mineralised, hard/rigid, canalicular system, regenerative capacity. Functions: provides framework, supports and protects, weight bearing, interacts with muscles to facilitate movement, bone marrow produces blood cells.