Epithelial tissue Flashcards
What is tissue?
A collection of specialised cells
What is an organ?
Made up of a variety of tissues
What is a system
An interaction of organs
What does epithelium line?
- Glands
- Bowel
- Skin
- Organs
What does endothelium line?
Blood and lymphatic vessels
What does mesothelium line?
Pleural and pericardial spaces
What are mesenchyme cells?
Cells that fill spaces between organs, including fat, muscle, bone, cartilage and tendon cells
What are neurons?
Conducting cells of the nervous system
What are stem cells capable of?
Capable of turning into one or several different cells
Two places where blood cells are present (other than blood)
- Lymph nodes
- Spleen
What is an oocyte?
An immature egg
What are germ cells?
The founder cells of all sexually reproducing organisms
What type of tissue lines secretory cells?
Epithelial
What are the possible changes in cells and tissues?
- Size
- Number
- Shape
- Metabolism
- Growth
- Death
What cellular effect does atrophy have?
Decrease in size
What cellular effect does hypertrophy have?
Increase in size
What cellular effect does hyperplasia have?
Increase in number
What cellular effect does dysplasia have?
Change in shape
What cellular effect does metaplasia have?
Cell is replaced with another
What cellular effect does neoplasia have?
Causes an abnormal growth
What cellular effect does necrosis have?
Cell death
What cellular effect does apoptosis have?
Programmed death
What could cause muscle atrophy?
Being bed ridden
What could cause muscle hypertrophy?
Exercise
What could cause muscle endometrial hyperplasia?
Prolonged oestrogen exposure
Give an example of cellular dysplasia
Irritation or inflammation due to smoking damages cilia of respiratory epithelial cells
Give an example of cellular metaplasia
Squamous metaplasia where ciliated respiratory epithelial replaced by squamous (no cilia)
Give an example of cellular neoplasia
Gene mutation - oncogene (chemical, radiation, viruses), can be benign and malignant
What could cause cellular necrosis?
Injury / disease
What happens during cellular apoptosis?
Cells shrink, chromatin fragments, apoptotic bodies form and are phagocytosed by macrophages
What happens during cellular necrosis?
Lysosomal enzymes digest cell (autolysis) and inflammation is triggered
What are affected cells called (tumours)
Neoplasms
What is the primary tumour?
The original tumour
What is the secondary tumour?
A tumour at sites distant from primary
What is a benign tumour?
A non-cancerous tumour
What is a malignant tumour?
A cancerous tumour
What are two different epithelial tissue?
- Epithelia
- Glandular epithelia
What are six different connective tissues?
- Fibroblast
- Adipose tissue
- Blood
- Lymphoid tissue
- Cartilage
- Bone
What are the three types of muscle tissues?
- Skeletal
- Cardiac
- Smooth
What are two types of neural tissues?
- Glia
- Neurons
Name a malignant tumour of the epithelia
Carcinoma
Name a benign tumour of the epithelia
Papilloma
Name a malignant tumour of the glandular epithelia
Adeno carcinoma
Name a benign tumour of the glandular epithelia
Adenoma
Name a benign tumour of fibroblast
Fibroma
Name a benign tumour of adipose tissue
Lipoma
Name a malignant tumour of blood
Leukemia
Name a malignant tumour of lymphoid tissue
Lymphoma
Name a benign tumour of cartilage
Chondroma
Name a benign tumour of bone
Osteoma
Name a malignant tumour of fibroblast
Fibro sarcoma
Name a malignant tumour of adipose tissue
Lipo sarcoma
Name a malignant tumour of cartilage
Chondro sarcoma
Name a malignant tumour of bone
Osteo sarcoma
Name a benign tumour of skeletal muscle
Rhabdomyoma
Name a malignant tumour of cardiac muscle
Cardiac sarcoma
Name a benign tumour of smooth muscle
Leiomyoma
Name a malignant tumour of smooth muscle
Leiomyo sarcoma
Name a malignant tumour of gila tissue
Glioma
Name a malignant tumour of neurons
Neuroblastoma
Are blood vessels present in epithelia?
No
Where does epithelia get its nutrition?
Via underlying tissue
What does lining epithelia do?
Regulate the passage of material in/out of body
Examples of the function of lining epithelia
- Gut - nutrients
- Lungs - gases
- Kidney - water, ions
- Skin - water
What do secretory cells do?
Secrete body fluids
Where are secretory cells present ( x 2)
- Glands
- Ducts
What two types of glandular epithelia are there?
- Exocrine
- Endocrine
What is surface epithelial classified as?
- Simple
- Stratified
What are the three types of simple epithelial tissue?
- Squamous
- Columnar
- Cuboidal
What are the three types of stratified epithelial tissue?
- Squamous
- Cuboidal
- Columnar
What are the two types of special epithelial tissue?
- Sensory perception
- Reproduction
What are epithelial tissues innervated by and where?
Nerves particularly at base
What is the function of cell junctions?
Regulate passage of materials between cells and provide physical strength
Are epithelial cells far apart or close together?
Close together - minimal matrix between cells
Function of exocrine glands
Discharge products via duct
Function of endocrine glands
Secrete hormones into bloodstream
What are the two types of exocrine glands?
- Simple
- Compound
What is the most common type of secretion?
Merocrine secretion
Give two examples of apocrine secretion
- Breasts
- Sweat glands
Give an example of a gland that’s involved in holocrine secretion.
Sebaceous gland
Give the functions of surface epithelium
- Covers exposed surfaces
- Lines internal passageways and chambers
- Highly cellular
- Capacity to regenerate
- Provide physical protection
- Control permeability
- Provide sensation
What is the term for a tissue having few or no blood vessels?
Avascular tissue
What does simple epithelial mean?
Has one layer and permeable
What does stratified epithelial mean?
Many layers, protective
What does squamous mean?
Thin, flat, irregular
What does cuboidal mean?
Box-like
What does columnar mean?
Tall, slender, rectangular
Give three examples of surface specialisation in epithelial tissue.(features)
- Keratin
- Microvilli
- Cilia
What is a feature of simple squamous?
Diffusion
What is a feature of simple cuboidal?
Synthesis of hormones
What is a feature of simple columnar?
Digestion, absorption, lubrication
What is a feature of stratified cuboidal?
Saliva
What is a feature of stratified squamous?
Protection
What is a feature of stratified Columnar?
Saliva
What is a feature of pseudostratified columnar?
Airways
What is a feature of transitional epithelium?
Distention
What is an example of simple squamous?
Blood vessels
What is an example of simple cuboidal?
Thyroid gland
What is an example of simple columnar?
Small intestine
What is an example of stratified squamous?
Skin
What is an example of stratified cuboidal?
Salivary gland
What is an example of stratified columnar?
Salivary duct
What is an example of pseudostratified columnar?
Trachea
What is an example of transitional epithelium?
Bladder
What is the function of simple cuboidal epithelium?
Synthesis & liberation of hormones
Give two locations of simple cuboidal
- Ducts
- Glands
Give a characteristic of simple cuboidal
Single layer of box-shaped cells
Give three functions (and via what?) of simple columnar
- Digestion (via enzymes)
- Absorption (via microcilli)
- Lubrication (via mucous cells)
Give a characteristic of stratified squamous
Many layers (with or without keratin)
Give three functions of stratified squamous
- Protection
- Moist surface resists dehydration
- Thermoregulation and sensation
Give an example of stratified cuboidal
Salivary gland
Give an example of stratified columnar
Salivary gland duct
Give two characteristics of pseudostratified columnar ciliated
- One layer of cells
- Only tall ones reach surface
Give four functions of pseudostratified columnar ciliated
- Secrete mucus (goblet cells)
- Trap particles (mucus)
- Move mucus (cilia)
- Clean, warm, moisten (e.g. air)
Give a characteristics of transitional epithelium
Many layers; all irregularly rounded
Give a function of transitional epithelium
Give a function of transitional epithelium
Where is transitional epithelium found?
Ureter and bladder
What is the function of basement membrane?
Anchors epithelial cells to underlying tissue
What can be on the free surface (x 3)
- Keratin
- Cilia
- Microvilli
What is the function of keratin (free surface)?
Protection
What is the function of cilia (free surface)?
Increase surface area and particle movement
What is the function of microvilli (free surface)?
Increase surface area and particle movement
What are the four intercellular junctions?
- Tight junctions
- Adherent junction
- Gap junction
- Desmosome
Function of tight junction
Cell-cell contacts (virtually impermeable to fluid)
Function of adherent junction
Cell-cell contacts
Function of gap junction
Permit passage of ions & molecules between cells
Function of desmosome
Cell-cell contacts
Function of basement membrane
- Separates epithelium, mesothelium and endothelium from underlying connective tissue
- A matrix that anchors epithelial cells to underlying tissue
Characteristics of basement membrane
Thin, fibrous, non-cellular tissue
What does proliferation in epithelia occur via?
Mitosis
NB! Give the four steps in proliferation of epithelial tissue
- Microtubules form
- Chromosomes duplicate & align at equator (metaphase)
- Chromosomes pull apart
- Cell divides
What happens in metaphase arrest?
Vincristine (VCR) prevents formation of microtubules
When can vincristine be injected?
3h before removal of tissues