Anatomy, Cells, Tissues Flashcards
What are the four types of tissue?
Connective, epithelial, nervous, muscle
What is epithelial tissue for?
Covers surfaces externally and lines surfaces internally.
Involved in absorption (intestine), secretion (glands), protection (skin)
How is epithelium structured?
Sheets of cells held together by a basement membrane, containing little non-cellular material (as suppose to connective tissue that has lots of fibrous tissue involved)
No blood supply, rely on diffusion for oxygen, nutrients
Joined by cell to cell junctions
What are the three main criteria for classifying epithelia?
How many layers? One - simple, more - stratified
What shape is the cell? Flat/squamous, cuboid or columnar
Any specialisations on the free (apical) surface? Cilia, microvilli, keratin
What epithelium would you find living alveoli in the lungs?
Simple squamous epithelium - thin surface for gas exchange
What epithelium lines ducts? Eg kidney tubules
Simple cuboidal epithelium - regions that need to keep their shape
What epithelium would you find in the gut?
Simple columnar epithelium - large surface area for absorption, contain microvilli to increase SA
What is pseudo stratified epithelium?
It looks as though it is made of several layers but is only one layer of different sized sells
What epithelium would you find lining the tubes of the respiratory tract?
Pseudo stratified ciliated columnar epithelium - contains goblet cells that secrete mucus which traps dust and foreign particles. Cilia move the dust etc away from entering the system
What is transitional epithelium?
Stratified, containing cells of different shapes, stretches easily.
Found in the bladder and other parts of the urinary tract
What is stratified squamous epithelium?
Found where the surface is likely to suffer from friction/abrasion, with a lot of wear (tongue)
What is the main difference between human tongue and skin?
Tongue is soft but skin has a thick layer of dead cells on the outside which becomes keratinised
Tigers tongue has keratinised structures used to help tear flesh from bone
What forms as a response to repeated abrasion?
Corns and callouses on feet, vocal fold nodules, areas subject to larger amounts of repeated abrasion
What epithelium covers vocal cords?
Stratified epithelium
What is muscle tissue for?
Responsible for producing movement within the body
Smooth muscle structure:
Uninuclear cells
Not striated
Not under voluntary control
Long, slow contraction (slow to tire)
Where is smooth muscle found?
Viscera e.g in stomach, of the gut, urinary system, blood vessels, respiratory system, skin, endocrine system
Striated muscle structure:
Fibres that are multi-nucleated: lots of energy
Striated
Voluntary
Fast contraction (tires quickly)
Where is striated muscle found?
Skeletal muscles, diaphragm, upper part of oesophagus
Cardiac muscle structure:
Uninuclear cells linked by intercalated discs that allow fast conduction through heart muscle
Striated
Not under voluntary control (does not tire)
Where is cardiac muscle found?
In the wall of the heart, needs a constant blood supply provided through coronary arteries, otherwise die
What are connective tissues for?
Support or packing
Types of connective tissue?
Not so easily to classify: basic loose connective tissue, bone, cartilage, blood
What is the structure of basic loose connective tissue?
A mesh of thin (flexible) elastin fibres and thick stronger collagen, interspersed with fibroblast cells which synthesise the fibres
