Tissues and Histology - Video Flashcards

A comprehensive set of practice flashcards covering cell discovery, tissues, epithelial and connective tissues, muscle, nervous tissue, glands, and tissue repair, based on the lecture notes.

Who discovered cells and in what year, and what observation led to naming them 'cells'?

Robert Hooke in 1665 observed cork slices and saw tiny hollow compartments; he called them 'cells' because they reminded him of rooms.

What did Hooke actually observe in the cork that led to the term 'cell'?

Cell walls and empty space in dead plant tissue, not living cells.

What is Histology?

The study of tissues using microscopy.

Name three common microscopy techniques used in histology.

Light microscopy (LM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM).

What are prokaryotic cells and name some typical components shown in bacterial diagrams?

Prokaryotic cells lack a nucleus; typical components include bacterial chromosome (nucleoid), fimbriae, ribosomes, plasma membrane, cell wall, glycocalyx, and flagella.

Where is the bacterial chromosome located?

In the nucleoid region of the cell.

What is the function of fimbriae in bacteria?

To help bacteria adhere to surfaces.

What is the glycocalyx?

A protective, sugar-rich layer outside the cell wall that helps with protection and adherence.

Which cellular structure is responsible for protein synthesis in bacteria?

Ribosomes.

What structures enable bacterial motility?

Flagella.

Name a key organelle and a feature in eukaryotic cells involved in protein synthesis and processing.

Ribosomes synthesize proteins; the endoplasmic reticulum (rough ER) and Golgi apparatus process and package proteins.

What are the three components of the cytoskeleton in eukaryotic cells?

Microfilaments, intermediate filaments, and microtubules.

What cell surface feature increases absorption area and is common in some epithelia?

Microvilli.

Which organelle is involved in lipid synthesis and detoxification in the cell?

Smooth endoplasmic reticulum (ER).

Which organelle is the cell’s 'control center,' housing genetic material and the nucleolus?

Nucleus (nuclear envelope surrounds it; nucleolus is inside).

What is chromatin?

The material that makes up chromosomes; DNA and protein that package genetic information in the nucleus.

What organelle contains enzymes and acids to digest waste and worn-out cell parts?

Lysosome.

Which organelle is the powerhouse of the cell, generating ATP?

Mitochondrion.

What is the Golgi apparatus responsible for?

Modifying, sorting, and packaging proteins and lipids for secretion or delivery to other organelles.

What is a peroxisome and its general function?

A small organelle containing enzymes to break down fatty acids and detoxify harmful substances.

What cellular component helps organize and move materials within the cell and includes microtubules and actin filaments?

The cytoskeleton (microfilaments, intermediate filaments, microtubules).

What cellular surface structure participates in absorption and secretion and may be found on some epithelia?

Microvilli.

Name the three main types of muscle tissue.

Skeletal muscle, cardiac muscle, and smooth muscle.

What are the hallmark features of skeletal muscle?

Long, cylindrical multinucleate cells with obvious striations; voluntary movement.

What distinguishes cardiac muscle from other muscle types?

Branched, striated, typically single nucleus per cell, and has intercalated discs; involuntary control.

What are intercalated discs and in which muscle type are they found?

Specialized junctions between cardiac muscle cells that facilitate synchronized contraction.

What are striations and which muscle type shows them?

Alternating light and dark bands seen in skeletal and cardiac muscle fibers; smooth muscle lacks striations.

Describe smooth muscle and where it is typically found.

Spindle-shaped cells without striations; involuntary; found in walls of hollow organs.

What are the four basic tissue types?

Epithelial, connective, muscle, and nervous tissue.

List five distinguishing features of epithelial tissues.

Polarity, specialized contacts, supported by connective tissue, avascular but innervated, regeneration.

How are epithelia classified by cell layers and by cell shape?

By layers: simple (one layer) or stratified (multiple layers); by shape: squamous, cuboidal, or columnar.

What is an example of simple squamous epithelium and its main function?

Location examples: kidney glomeruli, air sacs of lungs, lining of heart and vessels. Function: diffusion and filtration, with lubrication in serosae.

Where is simple cuboidal epithelium typically found and what is its function?

Location: kidney tubules, ducts and secretory portions of small glands, ovary surface. Function: secretion and absorption.

What characterizes simple columnar epithelium and where is it usually located?

Single layer of tall cells; contains microvilli and goblet cells; location includes digestive tract and gallbladder; function: absorption and secretion.

What is pseudostratified columnar epithelium and where is it found?

Single layer of cells of differing heights that looks stratified; often has cilia (trachea) or nonciliated (sperm-carrying ducts). Function: secretion and propulsion of mucus.

What is transitional epithelium and where is it located?

Stratified epithelium that can stretch; lines the ureters, bladder, and part of the urethra.

What is the difference between simple and stratified epithelia in terms of function?

Simple epithelia are typically involved in diffusion, absorption, and secretion; stratified epithelia provide protection against abrasion.

What is the primary difference between exocrine and endocrine glands?

Exocrine glands secrete onto surfaces or cavities via ducts; endocrine glands secrete hormones directly into the blood without ducts.

What are goblet cells and where are they located?

Unicellular exocrine glands that secrete mucus; often found in simple columnar and pseudostratified epithelia of the digestive and respiratory tracts.

What are the two main duct structures in multicellular exocrine glands and what do they mean?

Simple (ducts are unbranched) and Compound (ducts are branched).

What are the two main shapes of secretory units in multicellular glands?

Tubular (tubular secretory units) and Alveolar (acinar) secretory units.

Name the three modes of secretion in human exocrine glands and give a characteristic example for each.

Merocrine: secretions by exocytosis (e.g., sweat glands); Holocrine: whole secretory cell ruptures (e.g., sebaceous glands); Apocrine: apex of the cell released with secretions (controversial in humans, e.g., some mammary gland cells).

What are the three main elements of connective tissue, and which two form the extracellular matrix?

Ground substance, fibers, and cells; ground substance and fibers together form the extracellular matrix.

What is ground substance and what does it contain?

A gel-like substance filling space between cells; contains cell adhesion proteins, laminin, interstitial fluid, and proteoglycans.

Name the three types of connective tissue fibers and a key property of each.

Collagen fibers (high tensile strength), Elastic fibers (stretch and recoil), Reticular fibers (form networks).

What is the difference between 'blast' and 'cyte' cells in connective tissue?

'Blast' cells are immature, active secretors of ground substance and fibers (e.g., fibroblasts, chondroblasts, osteoblasts); 'cyte' cells are mature, less active, maintaining the matrix.

Describe areolar connective tissue and its role.

Loose connective tissue with a gel-like ground substance and all three fiber types; wraps and cushions organs; widely distributed under epithelia.

Describe adipose tissue and its primary function.

Loose connective tissue with adipocytes; stores fat, insulates, and protects organs.

What is reticular connective tissue and where is it located?

Loose network of reticular fibers forming a soft internal skeleton (stroma) that supports lymphoid organs like lymph nodes, bone marrow, and spleen.

What distinguishes dense regular connective tissue and where is it typically found?

Primarily parallel collagen fibers with fibroblasts; provides tensile strength in one direction; found in tendons and ligaments.

What distinguishes dense irregular connective tissue and where is it found?

Densely packed collagen fibers arranged irregularly; withstands tension from many directions; found in dermis and fibrous capsules of organs.

What is the role of dense elastic connective tissue and where is it located?

Dense tissue rich in elastic fibers that allows recoil after stretching; found in large artery walls (e.g., aorta) and certain ligaments.

Describe hyaline cartilage and its primary locations.

Amorphous but firm matrix with sparse visible collagen; chondroblasts produce matrix; supports and cushions; found in embryonic skeleton, ends of long bones, costal cartilages, nose, trachea, larynx.

What makes elastic cartilage distinct and where is it found?

Cartilage with a high content of elastic fibers; maintains shape while being flexible; found in the external ear and epiglottis.

What characterizes fibrocartilage and its function/location?

Matrix similar to hyaline but with thick collagen fibers; strong tensile strength to absorb shock; found in intervertebral discs, pubic symphysis, knee joints.

What is bone tissue composed of and what are its major functions?

Hard, calcified matrix with collagen fibers; osteocytes in lacunae; highly vascularized; supports, protects, stores minerals, and houses marrow for hematopoiesis.

What is blood connective tissue and its main components?

Fluid connective tissue with red blood cells, white blood cells, and platelets in plasma; transports gases, nutrients, wastes, and other substances.

What are the three types of muscle tissue and a key feature of each?

Skeletal (voluntary, striated, multinucleate), Cardiac (involuntary, striated, intercalated discs), Smooth (involuntary, non-striated, spindle-shaped).

What is nervous tissue and its two main cell types?

Main component of the nervous system; neurons (generate and conduct impulses) and supporting (glial) cells that support, insulate, and protect neurons.

What is tissue regeneration and fibrosis in the context of wound repair?

Regeneration restores tissue with original tissue; fibrosis forms scar tissue that heals the area but may impair function.

What is a potential clinical consequence of scar tissue forming in the heart?

Scar tissue can impair heart function, reduce volume capacity, block movement of substances, and hinder muscle contraction or nerve signaling.