Tissues Flashcards
(31 cards)
Tissues
Cells that are arranged in organized layers
4 main tissue categories
Epithelial, connective, nervous, muscle
Epithelial tissue
Refers to the sheets of cells that cover exterior surfaces of the body, line internal cavities & passageways, and form certain glands
Connective tissue
Binds the cells & organs of the body together & functions in the protection, support, & integration of all parts of the body
Muscle tissue
Excitable, responding to stimulation & contracting to provide mvmt, & occurs in 3 types:
1. Skeletal (voluntary)
2. Smooth (internal, hollow organs)
3. Cardiac (heart)
Nervous tissue
Excitable, allowing propagation of electrochemical signals in the form of nerve impulses that communicate between diff. regions of the body
Simple squamous epithelium
Location: lining of small intestine (lumen); lungs (alveoli)
Job: thin layer, permeable; O2 can freely diffuse into the capillaries
Simple cuboidal epithelium
Location: kidney tubules, thyroid gland
Job: thicker than squamous; absorptive & secretory (secretes substances, not mucus); move ions around across the layer
Simple columnar epithelium
Bulkiest of cell shapes; more substance & more function; goblet cells, ability to secrete mucus
Job: add mucus to smooth things along
Location: large intestine, large bronchioles
Pseudo-stratified columnar epithelium
Little more protection via bulk
Job: move mucus & other crap up & away from the lungs (delicate structures); contain goblet cells (secrete mucus); cells are ciliated, allow for paddle- like mvmt of unnecessary particles from the trachea
Stratified squamous epithelium
Adds substance to areas of lots of friction; found in epidermis (keratinized); stratum corneum
Transitional epithelium
Location: urinary bladder & ureters
Job: ability to stretch & flatten out
- stratified & different shaped cells
Apical- squamous-> columnar-> cuboidal- basement
Connective tissues
Job: connect things
Cells surrounded by extracellular matrix
Fibers run through ground substance; ground substance is the medium that the cell is in (usually interstitial fluid)
4 CT Types
Fibrous, adipose, supportive, fluid
Fibrous loose areolar CT
More common; have it everywhere - under skin, around organs; all 3 fiber types, cushion-like
Fibrous loose reticular CT
Restricted to lymphatic system; different fiber arrangement- reticular fibers form network; acts like a sponge for lymph fluid
Fibrous dense regular CT
Fibers run in a regular pattern (all in the same direction); specializes in tension in one direction
Example: calf to heel
Fibrous dense irregular CT
Fibers run in all different directions; needs to withstand being pulled in many different directions
Example: the dermis
Adipose CT
Cell type: adipocyte
Highly specialized; store fat/lipids; used for long-term energy storage and for cushioning; plays part in thermoregulation;
Example: in front of kidneys and behind the eyes
Supportive bone CT
Cell type: osteocyte
Cell matrix is calcified (minerals are added to make it rigid instead of soup like); balance between mineral deposits and collagen; vascularized tissue
Supportive SPONGY bone CT
Find in flat bones (skull); much lighter
Compact bone -> spongy <- compact bone (forms sandwich)
Supportive COMPACT bone CT
Trunk arrangement; osteocyte is located in the lacuna; vascularization happens through the central canal
Supportive Cartilage CT: hyaline
Cell type: chondrocyte; fine and dispersed fibers and ground substances has a glossy look to it; lagoon (lacuna) surrounds the chondrocyte and secretes ground substance; avascular
Supportive cartilage CT: elastic
Can clearly see elastic fibers in the ground substance; allows for some stretchiness; avascular
Example: found in the external inner ear (pinna) and epiglottis
