4-1. Tissues Flashcards
tissue (define)
similar cells with a common function
histology
study of tissues
What are the four main tissue types?
epithelial
connective
muscle
nervous
Epithelial tissue (define)
sheets of tightly packed cells covering a body surface or lining a body cavity
What are four characteristics of epithelial tissue?
polarity (have an apical surface exposed to exterior and a lower basal surface)
supported by connective tissue (rest on connective tissue - layer of ECM between them is the basement membrane)
avascular but innervated
regeneration (continue to divide by mitosis to replace old cells damaged or lost)
What are the classifications of epithelia?
two names - first name indicates number of cell layer sand second name describes shape of cells
simple epithelia
one layer of cells, found in areas with minimal wear and tear, specialized for absorbtion or filtration
stratified epithelia
cells stacked in several layers, found in areas with high wear and tear, specialized for protection
squamos
flat, scale like cells
cuboidal
box like cells as tall as wide, large round nucleus in middle
columnar
tall, long, thin cells with oval nucleus at one end
simple squamos epithelium
F: allows passage of materials by diffusion or filtration quickly
L: air sacs of lungs, lining of heart and blood vessels
simple cuboidal epithelium
F: secretion and absorbtion
L kidney tubuals
simple columnar epithelium
F: absorbtion, secretion of mucus and enzymes
L: lines most of digestive tract
pseudo stratified columnar epithelium
F: secretion of mucus
L: trachea, most of upper respitory tract
stratified squamos epithelium
F: protection
L: epidermis of skin
transitional epithelium
F: allows stretch when full of urine
L: lines the ureters, bladder and part of urethra
blandular epithelium
highly specified to secrete substances; exocrine and endocrine
exocrine
glands secrete products into duct that empty onto the skin or in the lumen of a hollow organ
endocrine
secrete hormones direclty into the blood, are ductless
What are some examples of exocrine glands?
sweat, salivary, lacrimal
What are some examples of endocrine glands?
adrenal, thyroid, pituitary
connective tissue (def)
most abundant and widely distributed in body, degree of vascularity is highly variable
What are five functions of connective tissue?
- binds organs together
- protection
- support
- insulation
- transportation
what are the three structural elements of connective tissue?
ground substance, fibers, and cells
connective tissue is composed mostly of ___
a non-living extracellular matrix made of ground substance and fibers, separating living tissue cells
What are the four types of connective tissue?
Connective tissue proper
Cartilage
Bone
Blood
connective tissue proper
gel-like ground substance, all three fiber types
binding tissue, resists stress and tension
What are the three types of fibers?
collagen, reticular, and elastic
What are the two types of connective tissue proper?
loose connective tissue
dense connective tissue
loose connective tissue
loosely woven, irregular arrangement of fiber and cells in a gel like matrix
L: under skin, around kidneys, around eyeballs, within abdoman, in breasts
F: reserve food, insulate, protect organs
What are three types of loose connective tissue?
areolar, reticular, and adipose
adipose
a type of loose connective tissue - a large drop of fat takes of most of the space in adipocytes, tightly packed and highly vascular
dense connective tissue
closely packed bundles of thick fibers with little ground substance and fewer cells, also called fibrous connective tissue
L: tendons, most ligaments, dermis of skin, fibrous capsules of organs and joints
F: provide strong attachment between structures, can withstand applied force
cartilage
tough but flexible, no blood vessels or nerves. Dense network of collagen and elastin in firm ground substance. The chondrocytes are found in cavities within the matrix. surface is surrounded by perichondrium membrane
What are the three types of cartilage?
hyaline
fibro
elastic
hyaline
“gristle”, bluish white shiny mass with numerous chondrocytes and collagen fibers
F: supports and reinforces, cushioning, reduces stress
L: embryonic skeleton, covers the end of bones at joints, forms costal cartilage, nose, trachea, larynx
fibro
rows of chondrocytes alternate with rows of thick visible collagen fibers, similar matrix to hyaline but less firm
F: strong support, withstand heavy pressure
L: intervertebral disk, pubic symphosis, discs of knees
elastic
threadlike network of elastic fibers
F: maintains shape of structure while allowing flexibility
L: external ear, epiglottis
bone
living osteocyte and network of collagin fibers are embedded in a hard mineral calcium matrix, well supplied with blood vessels
L: skeleton
F: supports and protects, provides levers for muscles, stores calcium, blood cell formation
What are the two classifications of bone tissue?
spongey and compact
blood
living cells (RBCs and WBCs) in a fluid matrix called plasma
L: within blood vessels and heart
F: transport of respitory gasses, nutrients, and waste
muscle
highly cellular, well-vascularized tissue made of elongated cells called muscle fibers (no matrix)
F: most types of body movement
L: skeletal muscle attached to bones or occasionally to skin
What are the three types of muscle tissue?
skeletal, cardiac, smooth
skeletal muscle
attached to bones by tendons and responsible for voluntary movement. fibers are long, thin and multinucleate. have obvious strations
cardiac muscle
striated fibers branch and are bound by thickened areas called intercalated discs. found in walls of heart and propels blood into circulation. involuntary
smooth muscle
non-striated fibers are spindle shaped with a central nucleus. found in walls of hollow organs and propels substances along internal passages. involuntary
nervous
makes up nervous system (brain, spinal cord and nerves) which regulates and controls body function
What are the two types of nervous tissue?
neuron and neuroglia
neuron
highly specialized nerve cells that generate and conduct nerve impulses
neuroglia
cells that support, insulate and protect the delicate neurons. do not conduct nerve impulses. frequent site of tumors in nervous system (aka “nerve glue”)
