Ch. 4 Flashcards
Tissues
- epithilial (mainly about cells)
- connective (extracellular matrix)
- muscle (em)
- nervous (em)
Embryonic Tissue
Mesenchyme: all connective tissues start from this
Extracellular Matrix
The compostition of the noncellular substances surrounding the cells
Germ Layers
(embryonic layers)
- ectoderm: outside; nervous, integumentary system
- endoderm: inside; digestive system
- mesoderm: betweeen; skeletan and muscular
Epithelial tissues
- covering
- free surface: outside; faces the opening or interior; not all mad the same (ie. smooth)
- lateral surfaces: connects to the neighboring cells
- basal surface: connects to the basement membrane
- basement membrane: helps attach epithelial cells to underlying tissues
Function
Diffusion
- simple squamous
- blood and lymphatic capillaries, alveoli of lungs
Function
Filtration
- simple squamous
- bowman capsules of kidneys
Function
Secretion or absorbtion
- simple squamous (mesothelium)
- simple cuboidal (choroid plexus)
- simple columnar (stomach, small/large intestine, uterus)
Function
Protection
- simple squamous (endothelium and mesothelium)
- stratified squamous (skin, corneas, mouth and throat)
Function
Movement of mucus
- simple cubodial (terminal bronchioles of lungs)
- simple columnar (bronchioles of lungs)
- pseudostratified columnar (larynx, nasal caivty, sinuses, etc)
Function
Stretching
- transitional (urinary bladder, ureter, superior part of urethra)
Types of Epithelial
- simple: protection against friction and abrasion; single layer
- stratified: barrier and protection; more than one layer
- pseudostratified: every single cell is attached to the basement membrane
Types of epithelial II
- squamous: flat and scalelike; function is covering, simple diffusion, filtration, protection
- cubodial: cube shaped; function is secretion or absorbion, movement of mucus
- columnar: taller than they are wide; function is secretion or absorbion, movement of mucus
- transitional: roughly cuboidal to columnar when not stretched and squamouslike when stretched
Goblet cells
- specialized columnar cells
- responsible for synthesizing and secreting mucus
Ciliated
vs
microvilli
- cillia: extensions of cell and are encompased by plasma membrane; wave; large
- microvilli: increases surface area of cell for absorbtion and secretion; small
Cell connections
desmosomes
- rivets (compact/self contained)
- relatively weak binding between cells
- intermediate filaments that extend into the cytoplasm
Cell connections
hemidesmosomes
- similar to one-half of a desmosome
- anchor to basement membrane
- intermediate filaments
Cell connections
tight juntions
- hold cells together and form a permeability barrier (do not allow leakage)
- typically with adhesion belts
Cell connections
Adhesion belt
- found below the tight junction and acts as a weak glue that holds cells together
- continuous
- actin filaments
Cell connections
gap junctions
- small, specialized contact region between cells
- cytoplasmic exchange; allows for communication flow between cells
Glands
- secrete things
- most are multicellular
- some are unicellular
Glands
exocrine
- glands with ducts
- direct secretion into bloodstream (inside body)
Glands
endocrine
- no ducts
- secrete outside of the body
Glands
simple
- have a single duct
Glands
compound
- ducts that branch off of the main and then branch again
Glands
lumen
- internal space of gland
Glands
tubular
- glands with secretory regions shaped as tubules (small tubes)
Glands
acinar/alveolar
- saclike structure
- extend off base and form a bulbous
Glands
merocrine
- cells o the gland produce secrections by active transport or produce vessicles that empty their contents into the duct through exocytosis
Glands
apocrine
- secretory products are stored in the cell near the lumen and a portion of the cell is pinched off and joins secretions
Glands
holocrine
- secretory products are stored in the cells of the gland
- entire cells are shed in order to secrete
Connective tissue
Cells
- blast: creates the matrix
- clast: destroy, breakdown for remodeling
- cytes: maintain
- cells can transition from osteoblast to osteocyte
Connective tissue
extracellular matrix
Components:
- protein fibers
- ground substance
- fluid
Connective Tissue
Protein fibers
- collagen: long, complex protein fibers; bundle of individual fibrils
- reticular: flexible, loose, very fine collagen fibers (loose and curly)
- elastic: consist of proein call elastin; allows for stretchability
Connective Tissue
Collagen
- type I (most common): tendons/ligaments/skin/bone
- type II: cartilage
- type III: reticular fibers
Connective Tissue
Ground substance
what fibers are embedded in
- hyaluronic acid: long, unbranched polysaccharide (slippery, good lubericant)
- proteoglycans: the formation of glycosaminoglycans on a protein core
- adhesives: hold proteoglycan aggregates together and to other structures like plasma membrane
Connective Tissue
GS: proteoglycan aggregate
traps H2O that allows proteoglycans to return to original shape when compressed and deformed
Connective Tissue
GS: glycosaminoglycans
short chained polysaccharide and protein combination; are strung out on a protein core
Connective Tissue
Type: Loose Connective
fewer fibers, more space
- areolar: loose packing material of most organs and tissues
- adipose: specialized loose connective tissue; consists of fat cells, which contain large amounts of lipid
- reticular: full of reticular cartilage; loose, open, sponge like scaffolding; forms the framework of the lymphatic system
Connective Tissue
Types: Yellow adipose tissue
most abundent; adult; pure energy storage
Connective Tissue
Types: Brown adipose tissue
specialized for heat production; infant mammals
Connective Tissue
Type: Dense Connective
more fibers, less space
- dense regular collagenous: protein fibers are oriented primariy in one direction (parallel); tendons/ligaments
- dense regular elastic: parallel bundles of collagen fibers and elastic fibers; vocal chords/nuchal ligament
- dense irregular collagenous: protein fibers that are oriented randomly giving great strength; dermis of the skin
- dense irregular elastic: randomly oriented collagen fibers; walls of elastic arteries
Supporting Connective
Cartilage
- composed of cartilage within an extensive and relatively rigid matrix
- next to bone, firmest structure in body
- has no blood vessels or nerves which causes it to heal slowly
Supporting Connective
Hyaline cartilage
- equal amounts of collagen and proteoglycan aggregates
- spongy
- very smooth surface
- rib cage/trachea
Supporting Connective
Fibrocartilage
- more collagen fibers than proteoglycans
- much thicker than hyaline cartilage
- slightly compressed and very tough
- knee/jaw/between vertebrae
Supporting Connective
Elastic cartilage
- numerous elastic fibers in addition to collagen and proteoglycans
- external ears
Supporting Connective
Bone
hard connective tissue that consists of living cells and solid matrix (hydroxyapatite)
- spongy: spaces between trabeculae; more open space; red marrow support
- compact: more solid, with almost no space between thin layers
Fluid Connective
Blood
- fluid matrix is liquid
- solid components are: RBC, WBC, platelets, dissolved ion and proteins
Fluid Connective
Hemopoietic tissue
- forms blood cells
- found in the bone marrow (soft connective tissue in the cavities of bones)
- yellow marrow: fat storage area
Muscle Tissue
contractile
- skeletal: attaches to the skeleton and enables the body to move; voluntary; cells are long, multineclei, nuclei are on the periphery
- cardiac: muscle of the heart; involuntary; branched and connected by intercalated disks (contain gap junctions); centrally located nucleus
- smooth: forms walls of hollow organs, skin, eyes; involuntary; cells are tappered at each end, have a single nucleus, are not striated
Nervous Tissue
found in the brain, spinal cord, and nerves
characterized by the ability to conduct electrical signals call action potentials
Nervous Tissue
Neurons
communicate by action potentials and neurotransmitters
- cell body: main cytoplasmic chamber where the nucleus is
- dendrites: receive information and deliver to cell body; short and taper to a fine tip
- axons: transmit information away from the cell body to the next dendrite; long with a constant diameter
Nervous Tissue
Multipolar neurons
possess several dendrites and one axon
Nervous Tissue
Bipolar neurons
possess a single dendrite and axon
Nervous Tissue
Psuedo-unipolar
- single, short process that extends from the cell body
- process divides into two branches that extend towards the brain or the spinal cord
- two branches act as one axon although there are dendrite like receptors
Nervous Tissue
Neuroglia
support cells of the brain, spinal chord, and peripherial nerves; maintain neuronal functions
Membranes
thin sheet or layer of tissue that covers a structure or lines a cavity
Membranes
Mucous
consists of epithelial cells, basement membrane, lamina propria and sometimes smooth muscle; secretes to the outside
- lamina propria: thick layer of loose connective tissue
Membranes
Serous
layer of simple squamous epithelium, basement membrane, delicate layer of loose connective tissue
- mesothelium: layer of simple squamous epitelium
- serous fluid: secretes in small amounts; lubricates serous membranes in pleural, pericardial, and peritoneal cavities
Membranes
Synovial
made up of only connective tissue; line freely movable joints
- synovial fluid: rich in hyaluronic acid, making joints very slippery
