Week 4 - Tissue Level of Organisation Flashcards
What is the definition of Histology
The study of tissues and their arrangements in organs
What is a Histological Section
A very THIN TISSUE SLICES, generally 1 or 2 cells thick that is mounted on glass Microscope Slides and Dyed with various Stains to contrast cell structure
What is a thin tissue slice that is looked under a microscope called
A histological Section
What is the definition of Tissues
Group of similar cells (AND CELL PRODUCTS) that function together as a unit
What are Tissues Composed of in the broadest terms
Cells, Matrix
What are the main 4 types of TISSUE
Epithelial, Nervous, Connective, Muscular
What is the Tissue Matrix
Extracellular material that surrounds the cell
What is everything but the Cell called in a Tissue
Matrix
What is the definition of extracellular material
Nonliving matter secreted by tissue cells, composed of, Fibrous proteins and Clear gel known as ground substance or Extracellular Fluid
What is a structure with definite boundaries that are composed of 2 or more tissue types
Organs
What are the 3 types of Cellular Junctions
Tight, Desmosomes, Gap
What is the adhesion cellular junction called
Desmosomes
What are desmosomes made of
Intermediate filament (Keratin) and linking glycoproteins (cadherins)
What are the 2 main types of Epithelial Tissue
Simple, Stratified
What are the 6 main cell shapes
Squamous, Cuboidal, Columnar, Polygonal, Spheroidal or Ovoid, Fusiform, Fibrous
What shape are Squamous Shaped Cells
Thin, Flat, Scaly - (squashed looking)
What shape are Cuboidal Shaped Cells
Equal height and width
What shape are Columnar Shaped Cells
More tall then wide
What shape are Polygonal Shaped Cells
Irregular, angular shape with 4 or more sides
What shape are Spheroidal or Ovoid Shaped Cells
Round to Oval
What shape are Fusiform Shaped Cells
Elongated
What shape are Fibrous Shaped Cells
Long, Threadlike
What makes up the Matrix
Protein Fibres and Ground Substance
What is Ground Substance
an extracellular fluid, gel or rubbery or very hard substance that embeds cells and fibres in a tissue
What does Ground Substance help with when talking about injuries
absorbs compressive forces; protects more delicate cells from injury
What is the definition of Epithelial Tissue
A flat sheet of closely connected cells one or more cells thick
What’s another name for Epithelial Tissue
Epithelium
Where is Epithelial Tissue most commonly found
covering body surface, Lining body cavities, forming external and internal linings of many organs, most gland tissue
Where is Epithelial Tissue most commonly NOT found
Blood Vessels
What are the 3 different surfaces of an epithelial tissue
Basal (Basement), Apical, Lateral (Sides)
What is the Basement Membranes main function
Anchors epithelial tissue to connective tissue
What is the Basement Membrane made out of
Mainly made of protein; regulates exchange of materials between tissues
What are the 4 main categories of Simple Epithelium
Squamous, Cuboidal, Columnar, Pseudostratified Columnar
Is Pseudostratified Columnar a Simple or Stratified Epithelium
Simple
What are the main features of Simple Squamous Epithelium
Thin and Scaly, Single cell layer
What does Simple Squamous Epithelium PRIORITISE
Filtration and Diffusion
Where can Simple Squamous Epithelium be found
air sacs of lungs, serous stomach membranes, inner lining heart and blood vessels
What are the main features of Simple Cuboidal Epithelium
Square or rounded square shape, Single cell Layer
What does Simple Cuboidal Epithelium PRIORITISE
secretion and absorption
Where can Simple Cuboidal Epithelium be found
kidney tubules, liver or thyroid glands, mammary glands, salivary glands, ovaries
What are the main features of Simple Columnar Epithelium
Tall, Narrow, Single cell Layer, CONTAINS GOBLET CELLS, can be CILATED and NON CILATED
Where can Simple Columnar Epithelium be found
Inner lining stomach and intestines, gallbladder, uterus / fallopian tubes
What are the main features of Pseudostratified Columnar Epithelium
Short AND Tall Cells, LOOKS BILAYERED but every cell reaches the basement membrane, CONTAINS GOBLET CELLS, can be CILATED and NON CILATED
What are the 4 main categories of Stratified Epithelium
Stratified squamous epithelium - keratinized, Stratified squamous epithelium - nonkeratinized, stratified cuboidal epithelium, transitional epithelium
What are the main features of Stratified squamous epithelium - keratinized
Top layer is dead squamous cells packed with keratin, base layer is living cuboidal / columnar, Water repellant
What does Stratified squamous epithelium - keratinized PRIORITISE
PRIORITISES PROTECTION by resisting microorganism breaches
where can Stratified squamous epithelium - keratinized be found
epidermis, especially palms & soles
What are the main features of Stratified squamous epithelium - nonkeratinized
Does not have dead cells, provides abrasion resistant surface, moist/slippery
What does Stratified squamous epithelium - nonkeratinized PRIORITISE
PROTECTION
where can Stratified squamous epithelium - nonkeratinized be found
Tongue, oral mucosa, vagina
What are the main features of stratified cuboidal epithelium
Square or rounded square shape, two or more layers,
What does stratified cuboidal epithelium PRIORITISE
Protection and Secretion
where can stratified cuboidal epithelium be found
sweat gland ducts, sperm-producing ducts (seminiferous tubules) of testes, egg-producing vesicles (& follicles) of ovaries
What are the main features of transitional epithelium
Resembles stratified squamous but surface cells are rounded, not flat, Stretches to allow filling
What keeps the basal layers of cells protected in the Transitional Epithelium
apical umbrella cells protect underlying cells from acidic & hypertonic urine
where can Transitional Epithelium be found
ONLY in Urinary Tract
What is unique about Connective Tissue
The volume of extracellular matrix is greater than cell volume
What is the most abundant Tissue Type
Connective Tissue
Where are Connective Tissues commonly found
Blood Vessels
What is the definition of Connective Tissue
Tissue that supports, protects, and gives structure to other tissues and organs in the body
What are the 7 main categories of Connective Tissue Fibres
Collagen, Reticular Fibres, Elastic Fibres, Fibroplasts, Macrophages, Leukocytes, Adipocytes
What is the most common Connective Tissue Fibre
Collagen
What are the main features of Collagen Connective Tissue Fibres
Tough, flexible fibres that DO NOT STRETCH
where can Collagen Connective Tissue Fibres be found
Tendons, ligaments and deep layer of skin (dermis) and Also in matrix of cartilage and bone
What are the main features of Reticular Fibres
thin, glycoprotein-coated collagen fibres, Forms a matrix of reticular connective tissue, a spongelike framework for organs
where can Reticular Fibres be found
Spleen & lymph nodes
What are the main features of Elastic Fibres
composed of a stretchy protein called ELASTIN, os thinner than collagen fibres and coiled, allow tissue to spring back after stretching
where can Elastic Fibres be found
skin, lungs, arteries
What are the main features of Fibroblasts
They are the dominant cells in fibrous connective tissue, large cells that taper, produce fibres and ground substance of matrix
What are the main features of Macrophages
They are large phagocytic cells that engulf and destroy bacteria, foreign particles, and dead cells
What are the main features of Leukocytes
They provide defense against pathogens (bacteria, toxins etc)
What are the 2 main categories of Loose Connective Tissue
Aerolar and Reticular
What are the main features of Loose Aerolar Connective Tissues
Loose arrangements of collagenous and elastic fibres, scattered cells & abundant ground substance, loosely binds epithelial tissue to deeper tissues
Where can Loose Aerolar Connective Tissues be found
Surrounds blood vessels, found in fascia between muscles
What are the main features of Loose Reticular Connective Tissues
network of reticular fibres, reticular cells and fibroblasts, presence of white blood cells
Where can Loose Reticular Connective Tissues be found
lymph nodes, spleen, thymus and bone marrow
What are the 2 main categories of Dense Connective Tissue
Regular and Irregular
What are the main features of Dense Regular Connective Tissues
Densely packed, Parallel Collagen fibers, fibroblasts are compressed between collagen bundles, with very little ground substance and few blood vessels, and is adapted to forces acting in a consistent direction
Where can Dense Regular Connective Tissues be found
Tendons, ligaments, vocal cord and arteries
What are the main features of Dense Irregular Connective Tissues
Densely packed, Collagen fibers that run RANDOMLY, Very small open spaces (ground substance), High durability in multiple directions
Where can Dense Irregular Connective Tissues be found
deeper dermis, capsules around viscera, fibrous sheaths around cartilage, bones and nerves
What is the most dominant cell type in Adipose Connective Tissue
Adipocytes
What does Adipose Tissue look like
Tightly packed together and filled with triglycerides with very little cytoplasm
What are triglycerides
a common type of fat that accounts for about 95 per cent of all dietary fats. these get put through the blood stream for energy and stored in body fat to fuel the body between meals
What are the main functions of Adipose Connective Tissue
Energy Reservoir, Thermal Insulation, Anchors and cushions organs e.g. eyes and kidneys
What is most Adipose Tissue labeled as
White Fat
Do adipocytes multiply
no, they expand
what does an overabundance of adipose tissue correlate to
Obesity
What is brown fat
Heat generating tissue that burns calories and gets colour from abundance of mitochondria
