Tissues Flashcards
What type of epithelium is this?
Simple squamous
What type of epithelium is this?
Simple Cuboidal
What type of epithelium is this?
Simple Columnar
What type of epithelium is this?
Pseudostratified Columnar
What type of epithelium is this?
Stratified squamous
What type of epithelium is this?
Stratified Cuboidal
What type of epithelium is this?
Stratified Columnar
What type of epithelium is this?
Transitional
Describe what a glandular epithelium is
An epithelium composed of cells specialised to produce and secrete substances into ducts or into body fluids.
Usually found within a columnar or cuboidal epithelium.
What are the main features and functions of a simple squamous epithelium? Give an example.
- Single layer of thin, flattened cells
- Broad, thin nuclei
- Substances pass through easily
e.g. line alveoli in lungs, form the walls of capillaries, line blood and lymph vessels, covers the membranes that line the body cavities
What are the main features and functions of a simple cuboidal epithelium? Give an example.
- single layer of cube-shaped cells
- central, spherical nuclei
e.g. cover the ovaries, lines most of the kidney tubules, lines ducts of certain glands (where the free surface faces the lumen)
What are the main features and functions of a simple columnar epithelium? Give an example.
- longer than they are wide
- single layer of cells
- elongated nuclei found near basement membrane
- can be ciliated or non-ciliated
- can protect underlying tissues due to thickness
- secrete digestive fluid and absorb nutrients
- if specialised for absorption the cells often have microvilli
e.g. fallopian tube (ciliated), lining of the uterus (non-ciliated), lining of digestive tract
What are the main features and functions of a pseudostratified columnar epithelium? Give an example.
- nuclei lie at two or more levels in the row of aligned cells
- all cells reach basement membrane, not all reach free surface
- commonly have cilia
- contain goblet cells
e.g. line passages in respiratory system
What are the main features and functions of a stratified squamous epithelium? Give an example.
- many layers
- relatively thick
- cells divide in lower layers and push older one farther outward, where they flatten
- In the epidermis the cells undergo keratinisation
e.g. epidermis, lines oral cavity, oesophagus, vagina, and anal canal
What are the main features and functions of a stratified cuboidal epithelium? Give an example.
- two or three layers of cuboidal cells
- forms the lining of lumen
e.g. lines ducts in mammary glands, salivary glands, and pancreas. Forms lining of developing ovarian follicles and seminiferous tubules.
What are the main features and functions of a stratified columnar epithelium? Give an example.
- several layers
- superficial cells columnar, basal layers contain cuboidal cells
e.g. male urethra, ductus (vas) deferens, parts of pharynx
What are the main features and functions of a transitional epithelium? Give an example.
- specialised to change in response to tension
- when contracted it contains several layers of cuboidal cells
- forms a barrier that helps prevent contents of urinary tract diffusing back into the internal environment
e.g. lines urinary bladder, ureter, and superior urethra
What are the main features and functions of a glandular epithelium? Give an example.
- composed of cells specialised to produce and secrete substances into ducts or body fluids
- cells found in columnar or cuboidal epithelium
- one or more of these cells constitute a gland
e.g. salivary, sweat, mammary, and sebaceous glands
What is an exocrine gland? Give an example.
A gland that secretes its products into ducts that open onto surfaces.
e.g. sebaceous glands in the skin
What is an endocrine gland? Give an example.
A gland that secretes its products into tissue fluid or blood.
e.g. pituitary gland, pancreas, ovaries, testes, thyroid gland, and hypothalamus
What are the three classifications of exocrine glands? Describe briefly what each does.
- Merocrine: releases fluid by exocytosis
- Apocrine: lose small portions of their glandular cell bodies during secretion
- Holocrine: release entire cells that disintegrate to release cell secretions
What are the subclassifications of merocrine glands? Where are they found?
- Serous fluid: watery, high concentration of enzymes, lubricates, visceral and parietal membranes in abdominopelvic cavity
- Mucous: thicker, rich in mucin and abundantly secreted by cells for protection in the inner linings of the digestive, respiratory and reproductive systems.
What are the functions of connective tissue?
- binds structures
- provide support and protection
- serve as frameworks
- fill spaces
- store fat
- produce red blood cells
- protect against infections
- help repair tissue damage
What is a fibroblast?
Large, star-shaped cells that are the most commone type of fixed cell in connective tissue. They produce fibers by secreting protein into the extracellular matrix of connective tissues.
