Assignment 1 Chapter 5 Tissues (10/9/2015)
Tissue are classified by their structure and function
- Epithelial tissue
- Cover + protects body surface, body cavities lining, secretion, excretion, absorption
- Connective tissue
- Support body, connect + hold them together, transport substances, protect against germs
- Muscle tissue
- Allows for movement, contractility
- Nervous tissue
- Complex, communication between body parts; generate complex messages for body function
Epithelial Tissue
There are two types of epithelial tissue (or epithelium)
There are two types of epithelial tissue (or epithelium)
- Membranous
- [Covering or lining]
- Covers body and serous cavities (pleural, pericardial, peritoneal), blood, lymphatic vessels, respiratory, digestive, and genitourinary tracts
- Glandular
- Solid cords/specialized follicles, form secretory units of endocrine and exocrine glands
Epithelial tissue attach to basement membrane which is a the underlying layer of connective tissue, thin noncellular layer of adhesive, permeable material
They also have many special characteristics such as how they
- It's made up of glycoproteins
- Nutrients get to epithelial cells diffusing from capillaries through the basement membrane
They also have many special characteristics such as how they
- Fit closely together
- Have apical surface
- "The surface of the epithelial cell that is exposed to the body exterior or to the cavity of an internal organ"
- They're able to regenerate when they're well nourished
Membranous Epithelium can be classified on the bias of their cell shape
- Squamous
- Flat, platelike like fish scales! (Ew stinky, let's thing of another example... umm I can't think of anything ;^( )
- Cuboidal
- Cube-shaped
- Columnar
- Height is greater than it's wide. look narrow / cylindrical
- Pseudostratified columnar
- Oddly shaped columnar cells
- These don't reach the surface of the membrane
- Nuclei near top and near bottom making it look stratified but not; has only 1 layer
They can also be classified by the number of layers (Whoa! Layers!? They're almost as cool as sparkly glitter)
Now lets discuss structure and layers together!!!! (Here's a celebratory cookie that you can't eat : 🍪 ... Hey, it's better than nothing)
- Simple epithelium
- Has 1 layer
- Stratified epithelium
- It's layered
Now lets discuss structure and layers together!!!! (Here's a celebratory cookie that you can't eat : 🍪 ... Hey, it's better than nothing)
Simple Squamous
- Substances can diffuse through it quickly (Sanik speed)
- Makes up the alveoli (air sacs) of lungs, lining of blood, lymphatic vessels, pleura surface, pericardium and peritoneum
Simple Cuboidal
- A layer of cuboidal cells on basement membrane
- Found in glands and their ducts, ducts & tubules of organs like the kidney
Simple Columnar Epithelium
- A layer of columnar cells on mucous membrane surface
- Such as on stomach, intestine, uterus, uterine, tubes, parts of respiratory tract
- Goblet cells
- have secretory vesicles
- Cilia
- Microvilli
- Increases surface area
- Helpful in absorbing nutrients and fluids from the intestine
- Increases surface area
Pseudostratified columnar Epithelium
- Found in air passages of respiratory system, segments of male reproductive system (urethra)
- Look stratified but are a single layer of irregularly shaped columnar cells that touch the basement membrane
- They have many mucus secreting goblets and cilia
- The cilia helps move the mucus
Stratified Squamous
- Has multiple layers, flattened squamous cells at free.outer surface
- (Keratinized) Has keratin which gives it protective abilities for the skin covering our body surface
- (Nonkeratinized) Found in lining of vagina, mouth and esophagus.
- Surface is moist, serves for protection
Stratified Cuboidal
- Serves for protection
- Two or more rows place randomly over basement membrane
- Located at sweat gland ducts, pharynx, parts of epiglottis
Stratified Transitional
- Found in urinary bladder
- Subjected to stress and tension changes
- Tension increases, it expands and change from cuboidal to squamous in appearance
- Protects bladder wall from tearing when stretched
Glandular Epithelium
- Does secretory activity
- Function as unicellular glands or clusters, solid cords, specialized follicles as multicellular glands
- Their secretion is discharged into ducts, lumen of visceral structures, body surface or into blood
- Glands
- Exocrine glands
- Discharge secretion product into ducts
- Ex. Salivary glands
- Discharge secretion product into ducts
- Endocrine glands
- Ductless glands
- Discharge secretion products directly into blood or interstitial fluid
- Ex. Pituitary, thyroid, adrenal glands
- Ductless glands
- Exocrine glands
*Information was obtain from Anatomy & Physiology textbook and other online sources and used in a non-commercial way. I, in no way claim the information to be mine but simply have restated/rephrased it for the purpose of this school assignment. Still don't hurt me :P *