Lecture 3 - Tissues Flashcards
What are the 4 types of tissues
- > Connective
- > Epithelial
- > Muscle
- > Nervous
Where can you find epithelial tissue?
- > The inner and outer layers of organs
- > glands
- > lines every body surface and all body cavities
Functions of epithelial tissue
- > physical protection
- > selective permeability
- > secretions
- > sensations
What is the extracellular matrix?
- > substance produced by the cells of a certain tissue, located outside the cell which can contain protein fibres h2o, and dissolved macromolecules.
- > Anything that’s not a cell
- > Fibres + ground substance = EM
Explain all of the different layers of epithelium
simple - > single layer of cells
stratified - > two or more layers of cells
pseudostratified - > single layer but not all cells an atypical surface
Explain epithelial cell morphology
Squamous - > flattened; similar to fried egg
Cuboidal - > about the same size on all sides
Columnar - > taller than they are wide
What are ciliated epithelium
A region of epithelium consisting of columnar or cuboidal cells bearing hairlike appendages (cilia)
What is transitional epithelium
Mostly found in the urinary system, these cells are able to stretch and store toxins (urine)
- > not simple or stratified
What are the two types of glands
Endocrine glands - > do not posses ducts and secrete their products directly into the bloodstream
Exocrine glands - > posses ducts and their cells secrete their products into them; transporting them to where they need to go ie. sweat goes to sweat glands
Types of muscle tissue
- > skeletal
- > cardiac
- > smooth
multi-nucleated vs uni-nucleated
more than one nucleus vs single nucleus
characteristics of skeletal muscle cells
- > attached to bone
- > long & cylindrical
- > striated and voluntary
- > multi-nucleated
Characteristics of cardiac muscle cells
- > striated and involuntary
- > cells are branched (“Y” shape)
- > attached by intercalated discs
intercalated discs
strong gap-junctions which connect cardiac cells end-to-end
characteristics of smooth muscle cells
- > found in walls of most internal organs
- > short, wide in the middle and tapered at both ends (fusiform)
- > involuntary and non-striated
What are the two types of nervous tissue and what are they?
Neuron - > nerve cells that are capable of impulse propagation
Neuroglia - > cells that support the neuron
function of nervous tissue
communication and control of body functions
What is connective tissue
“glue” or “filler” of the body;
CT = cells + extracellular matrix
Functions of connective tissue
- > Physical protection
- > support & structural framework
- > binding of structures
- > storage
- > transport
- > Immune protection
classification of connective tissue
- > CT Proper
- > Supporting CT
- > Fluid CT
types of cells of CT proper
resident cells - > fixed in place
wandering cells - > wandering
fibres of CT proper
Collagen fibres: long, thick, strong
Elastic fibres: allow structures such as blood vessels stretch and relax
Reticular fibres: form mesh-like framework which provides structural integrity (like metal rods in concrete)
Ground substance of connective tissues
- > a combination of carbohydrates and proteins
- > a large gelatinous material that fills the spaces between fibres and cells; fills extracellular matrix
Categories of connective tissue proper
Loose CT: fewer proteins, more ground substance
Dense CT: more protein fibres, less ground substance
Types of Loose CT
- > areolar CT: can be distorted without damage
- > adipose CT: known as fat
- > reticular CT: contains reticular fibres and leukocytes
Types of Dense CT
Dense regular CT: collagen fibres run in same direction
Dense irregular CT: collagen fibres entend in many directions
Elastic CT: predominant elastic fibres provide ability to stretch and recoil
types of specialized connective tissue
supporting connective tissue - > bone - > cartilage fluid connective tissue - > blood
Components of fluid connective tissue
- > plasma: watery ground substance that contains proteins
- > erythrocyte: red blood cells
- > leukocyte: white blood cells
- > platelet: clotting agent
