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Ch 4: Tissuse level of organization

groups of similiar cells and extracellular products that carry out a common function
these cells have physical connections: sensory and function abilities to communicate with eachother.
Nervous tissuse
consist of nerve cells (neurons) and neuroglial
central nervous system (CNS)
brain and spinal cord
Peripheral Nervous system (PNS)
outter boundry nervous system, appendages
Autonomic nervous system (ANS)
sympathetic and parasympathetic nervous system
funtional unit of the nervous system
conducts impulses from one cell to another
has a nucleus
Neuroglial (glial) cells
support cells of the nervous system
aid in conducting impulses
Muscle Tissue
responds to stimulation from the nervous system causing contraction; produces voulntary and invoulntary movement
types designated by microscopic apperance, neural control and type
Connective tissuse
all CT is derived fron mesoderm
most diverse, abundant, widely distributed & microscopically variable of tissues
evolved to support, protecct and bund organs/body structures together
Extra Cellular Matrix (ECM)
contain fibers, cells, and ground substances
Collagen Fibers
most common(strong, stretch resistant) - seperates bones
Type 1: bones
type 2: cartilage
type 3: stroma of organs
type 4: basment membranes
Elastic Fibers
rubber-like flexible protien
seperates vertabre, spine
Reticular Fibers
form interwoven framework
very tough woven
network that allows support of organs ans resistaing damage
make collagen, elastic and reticular fibers
important for strength and strech resistance
immune cells
important for detecting pathogens and figting illness
fat cells
key for energy(energy reserve)
mesenchymal cells
'adult sperm cells'
support and repair
pigment cells
produce pigment and protection
Mast cells
contains histamine/stimulation inflammation
stimulates inflammation, puts pressure on nervous system and allows us to decet injury
Ground substance
gel like substance, can become mineralized and become bone
Tissuse fluid + protiens + polysaccharides
Fluid content determines the consistancy of the ground substance
Loose/Areolar CT
found everywhere in the body
loosely woven tissue with a fiber arragment that allows for distortion w/out damange
high fluid content easily permits nutrient and waste diffusion
very loose, lots of movement. allows for molecular moventment from high to low concentration
adipocytes provide protection, nutrient storage, and thermo regulation
white: pale yellow, less vasularized (found in brest, butt and thighs)
Brown: high viscularized for heat stimulation (in babies necks)
small, net thin
contains thin reticular fibers
forms stroma(framework) for organs like spleen, liver
functional cells enmeshed w/in stroma
acts as support system
Dense Regular
parallel bundles of collagen fibers provide unidirectional strength
tendons, ligament, and aponeroses
Dense irregular
randomly oriented fibers provide strength in all directions
in urinary bladder
contains more elastin that collagen
densely packed parallel bundles of elastin all for strength and recoil
large atrerites, some ligaments, in the vertebral column
supports soft tissues and provides s gliding surface
model for bone formation
ECM has a ground substance of chohdrotion, sulfate and hyaluronic acid
hyalin: densely packed collagen fibers
fibrocartilage: thick wavy bundles of collagen, allows compression
elastic: less collagen, more elastic fibers allows flexability
structural support
protects delicate tissuse/organs
muscle + bone = movenemt
mineral reserves
martix is solified due to calcium
bone forming cells
mature bone cells, new bone matrix
cells function in absorption
Fluis type CT
blood is a fluid CT w/ fermed elements
leukocytes/white blood cells (immune response)
platelets (blood clotting)
erythrocytes/red blood cells (carry oxygen)
Epithelial tissue
composed of one or more layers of closely packed cells
lines every body surface, all body cavities, the external and internal lining of many organs (protection)
constitutes the majority of exocrine and endocrine glands(secretion)
composed of cells that can absorb nutrient molecules(absorption)
epithelial tissue: protection
protection is aided by the ways cells in epithelium are packed
adhering - metwork of supportive microfillaments that wrap around cell
gap - adjacent cells linked via channes set it their cell membranes
tight - partial fusion of adjacent cell membranes
desmosomes - link adjacent cells at potential stress points
Glandular Epithelium
epithelial cells are capable of producing a secreting a specific substance
develops a layer form epithelial surface
serous glands
produce and secrete sweat, milk, tears, digestive juices
mucus glands
produce and secrete mucin which form mucus with water
mixed glands
salivary glands contain serous and mucus cells and produce a mixture of the two types
exocrine glands
gland is connected to an epithelial surface by a duct
secretory portion made of glandular cells that produce material
Duct portion lined with ductal cells that channel secreted materials
Ductless allowing straight into the blood stream
Excretion methods: Merocrine
packing their secretions in structures called secretory resicles
the gladular cells remain intact and are not damanged in anny way by producing the secretion
secretion becomes released out of the cell membrane
exeretion methods: holocrine
secretion produced through the destruction of the secretory cell
lost cells replaced through division at the gland base
cells burst due to secretion of a certain product
Excretion methods: apocrine
a combination of merocrine and holocrine
apical region becomes packed w/ secretory vessicles and then is pinched off
remaining cell stump regenerates (due to stem cells)
Endocrine Glands
glandular cells in endocrine glands have no connection to an epithelial surface (no ducts)
cellular products are secreted into bloodstream
use hormones as chemical messengers to influence cell activities elsewhere in the body
some organs are both exocrine and endocrine (pancreas, overies, testies)