4- Tissues Flashcards
4 Tissue Types
1- Epithelium (covering)
2- Connective (support)
3- Muscle (movement)
4- Nervous (control)
epithelium
- sheet that covers bodies surface or cavity
- forms most glands
- nearly all substances received or given off by body must pass across epithelium
diffusion
movement of molecules down their concentration gradient
secretion
the release of molecules from cells
absorption
bringing small molecules into the body
ion transport
moving ions across the interface
Special characteristics of epithelia
1- composed almost entirely of cells
2- adjacent epithelials are joined by cell junctions
3- cells apical and basal differ (polarity)
4- supported by connective tissue
5- avascular (lacks blood vessels) but innervated with nerve endings that do (also receive nutrients from capillaries)
6- regenerate lost cells quickly
simple squamous epithelium
one layer flattened cells
passage of materials by diffusion and filtrations
simple cuboidla epithelium
single cube layer
secretion and absorption
simple columnar epithelium
single tall layer, may have cilia and contain goblet cells
absorption, secretion of mucus, enzymes
ciliated type propels mucus
pseudostratified columnar epithelium
single layer of cells of differing heights
secretion of mucus, propels mucus
stratified cuboidal epithelium
two layers of cube cells
protection
stratified squamous epithelium
many layers watch the surface cells
surface is keratinized and dead
basal is active in mitosis
stratified columnar epithelium
basal cells cuboidal, superficial are elongated and columnar
protection, secretion
transitional epitelium
dome shaped
stretches and distends in urinary organs by urine
endocrine glands
lack ducts
produce hormones for specific target organs to tell them how to respond
exocrine glands
have ducts
secrete onto surfaces or body cavities
mucus-secreting glands
goblet cell
gathered in epithelial lining of intestines and respiratory tubes
mucin
glycoprotein (sugar protein) that dissolves in water when secreted
mucin and water is
mucus
simple glands
unbranched duct
compound glands
branched duct
alveolar
spherical sacs
3 Factors that bind epithelial cells
1- adhesion proteins
2- wavy contours (tongue/groove)
3- cell junctions
tight junction
strappy belt like
some proteins in plasma membrane are fused
closes off extracellular space
prevents molecules from passing through the intercellular space
adhesive belt junctions
transmembrane proteins attach to microfilaments of cytoskeleton and bind adjacent cells
(reinforces the tight junctions)
desmosomes
or anchoring junctions
linking glycoproteins or cadherins,
cytoplasmic face has plaque and keratin
inside is zipper like
internal tension reducing network of fibers
gap junctions
tunnel like squish flowers
allows ions and small molecules to pass from one cell to another
cilia
motile extensions of apical surface of membrane
basal body
centriole at the base of each cilium
4 Classes of connective tissue
1- CT proper
2- cartilage
3- bone tissue
4- blood
3 Characteristic of connective tissue
- fews cells and lots of extracellular matrix
- extracellular matrix composed of ground subtance and fibers
- from embryonic tissue
3 Types of protein fibers in connective tissue
1- collagen
2- reticular
3- elastic
What produces extracellular matrix?
Fibroblasts
In cartilage tissue the cells that secrete the matrix
chondroblasts
In bones cells that make matrix
osteoblasts
When cells are not actively secreting new matrix they are called?
Fibrocytes
Chondrocytes
Osteocytes
Two classes of connective tissue
loose and dense connective
Loose CT Areolar
gel like matrix, fibroblast, macrophages
cushions organs, macrophages phagocytize bacteria, inflammation, convery tissue fluid
Loose CT Adipose
closely packed adipocytes
reserve food fuel, prevent heat loss, support/protect organs
Loose CT Reticular
Dark reticular tree like fibrs in loose ground substance
soft internal skeleton that supports blood cells, mast cells and macrophages
Dense CT Irregular
irregularly arranged collagen fibers, elastic fibers, fibroblasts
withstands tension, structural strength
Dense CT Regular
Parallel collagen fibers, few elastic, fibroblasts
Attaches muscle to bone or bone to bone
withstands pulling stress
Dense CT Elastic
LOTs of elastic fibers
Recoiling of tissue after stretching, flow of blood through arteries, recoil of lungs
Cartilage Hyaline
chondroblast produce matrix and when mature chondrocytes lie in lacunae
support, resists compressive stress (ribs)
Cartilage Elastic
More elastic fibers in matrix
shape and flexibility (ear)
Cartilage Fibrocartilage
not firm matrix thick collagen fibers
absorb shock (between vertebrae)
Cartilage in bone
rough looking
stores calcium, mineral, marrow, blood cell formation
Blood cells
red and white in plasma
transport in respiratory gases, nutrients, wastes
Skeletal Muscle tissue
long cylinder like clear striations
voluntary movement
Cardiac muscle
striated with intercalated disks
propels blood
Smooth Muscle
spindle shaped no striations
propels substances along
Nervous tissue
Neurons branching contains nucleus
Transmit electrical signals
