tissues Flashcards
what are cell junctions?
gap junctions
tight junctions
desmosome
what are tight junctions?
they are tight so they do not allow movement between cells
ex: intestine, blood brain barrier, kidney
what is a gap junction?
have gaps allows the movement of ions
- transmission of charge
eg. heart, gut - parasympathetic and sympathetic wave like contraction in the gut moving through a gap junction
what is a desmosomes?
- prevent the pulling apart of tissues
- if we get a lot of mechanical stress on tissue then we get a desmosomes
- strong attachment
eg. skin, uterus, heart
heart contracts and fills there is stress on the heart
gap junctions and desmosos.
what is the definitions of tissues and what are the 4 types?
cells with similar structure and function
4 types:
- epithelial
-connective tissue
-nerve
-muscle
what is epithelial tissue?
every organ has a epithelial lining
eg. thoracic cavity wall, gut wall , skin
- inside and outside
glands:
exocrine: secrete into a duct , sweat glands, digestive enzymes
endocrine glands: specific to secreting hormones right into the blood
what is the meaning of stratified and simple squamous, and simple cuboidal, or stratified columnar?
stratified squamous- many layers
simple- one layer
squamous-squished cell, not round but squished
-lung tissue
simple cuboidal- one layer but more cubed
-found in gut
stratified columnar- the top stands taller and columns
what is the functions of the epithelial tissue?
protection - toxins, melanin, uv
absorption, secretion
ion transport, diffusion
filtration
forms slippery surfaces- esophagus to bring down food
what is simple squamous epithelium?
- put where we do not have a lot of wear and tear
- adapted for diffusion and filtration
eg. lung alveoli and bowmans capsule
what is stratified squamous epithelium
look at outer most layer to get the characteristic
-protects areas of wear and tear
-outer layer of skin, lining of mouth, vagina
what is transitional epithelium?
- contains cells can change shape
- in areas subject to stretching
eg. urinary bladder
what are the different specialized epithelial cells?
exocrine glands: secrete substances into ducts
e.g sweat glands, gut mucuses glands
endocrine glands : they are ductless
-secretes hormones into blood
-have more widespread effect
eg. thyroid
paracrine glands:
-secretes over short distances
-not go into blood but have a local affect
what is the unicellular exocrine glands or the goblet cell?
- goblet cells produce mucin
mucin+water-> mucus
we need mucus everywhere internal body always most time excretes mucus
(protects and lubricates) - goblet cell is a single cell
secrete out mucin which then makes the mucus
what are the different shapes of duct classifications?
simple vs compound
simple: comes out and has a coil tube
compound: has lots of branching
what are the main classes of connective tissue?
most abundant tissue
main classes:
cartilage
bone tissue
blood
fat
connective tissue
what is the connective tissue functions?
binds together, supports and strengthens
-protects and insulates internal organs
what are the two different connective tissue proteins?
- collagen- stiff protein, not very strechy
eg. tendon - elastin- strechy, eg. lung
what is the fibroblasts and ground substance?
fibroblasts are cells that secrete matrix proteins
-free macrophage
ground substance: os the matrix of loose connective tissue
what makes up the extracellular matrix?
collagen and elastin fibers
-viscous, gel-like ground substance
-sugars, proteins, and water
-cushions and protects body structure
what are the two types of connective tissue
-loose connective tissue or areolar, adipose tissue
- dense connective tissue
- regular vs irregular
what is areolar or loose connective tissue?
gel like matrix with all three fibers:
contains:
-fat cells
-white blood cells
-mast cells
-fibroblasts
surrounds all the blood vessels and organs, and borders all the other tissues in the body
what is the dense irregular connective tissue?
- irregularly arranged collagen and elastin
-withstrands tension/pulling
location:
-skin
-gut
-fibrous capsules of joints and organs
dont know where stress is coming from so we arrange fibers so it can withstand anything
what is the dense regular connective tissue
- most of the time we know which way the stress is coming from
- all the fibers are arranged in the direction of where the stress is going to come from
-some elastin, lots of parallel collagen fibers, poorly vascularized no blood
-eg. muscle and bone attachments
tendons and ligaments
what is the specialized connective tissues ?
bone:
forms the skeleton
-spongy vs compact
blood: transports materials such as glucose and oxygen
fluid matrix of :
- plasma (fluid)
-red blood cells
- white blood cells
-platelets
what are the different types of bones?
compact bone:
-harder -harversian systems
-found in outer layer of bones
usually shaft of long bones
spongy bone (lots or red bone marrow, but also yellow bone marrow):
made up of trabeculae (thin, bony plates) with spaces in between that are often filled with bone marrow
bone is what percent cells and what percent matrix?
10% cells and 90% matrix
what are some specialized connective tissues ?
cartilage: it can be a transitional tissue which bone develops
- maintains shape of certain body parts (nose, ears)
-cushions vertebrae (vertebrae’s disks), lines joint cavities
adipose tissue:
-fat cells
-functions in insulation, protection, and energy storage
what are the different types of cartilage?
-provides structure and support under compression
types:
fibrocartilage:
intervertebral disks between vertebrae
menisci in knee joints
- gives protection from compression
hyaline :
-forms embryonic structure, which later forms bone
-covers and protects ends of long bones in joints
elastic cartilage:
-flexible, outer ear, tip of nose
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR loose connective tissue?
Ground Substance: Gel-like, more ground than fibers and cells.
Fiber Type: Collagen, elastic, reticular; arranged randomly.
Main Cell Types: Fibroblasts.
Where Found: Skin, around blood vessels and organs, under epithelia.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR dense, irregular connective tissue?
Dense, Irregular Connective Tissue
Ground Substance: More fibers than ground.
Fiber Type: Mostly collagen; arranged randomly.
Main Cell Types: Fibroblasts.
Where Found: Muscle and nerve sheaths.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR Dense, regular connective tissue?
Ground Substance: More fibers than ground.
Fiber Type: Collagen; parallel arrangement.
Main Cell Types: Fibroblasts.
Where Found: Tendons and ligaments.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR adipose tissue?
Ground Substance: Very little.
Fiber Type: None.
Main Cell Types: Brown fat and white fat cells.
Where Found: Varies by age and sex.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR blood?
Ground Substance: Aqueous.
Fiber Type: None.
Main Cell Types: Blood cells.
Where Found: In blood and lymph vessels.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR cartilage?
Ground Substance: Firm but flexible; contains hyaluronic acid.
Fiber Type: Collagen.
Main Cell Types: Chondroblasts.
Where Found: Joint surfaces, spine, ear, nose, larynx.
summarize what is the ground substance, fiber type, main cell types, and where is it found?
FOR bone?
Ground Substance: Rigid due to calcium salts.
Fiber Type: Collagen.
Main Cell Types: Osteoblasts and osteoclasts.
Where Found: Bones.
what are muscle tissues?
moving skeleton, creating force and movement
three types:
-cardiac
-smooth eg. gut anyplace where there is muscle you do not control
-skeletal (diaphragm, biceps, leg muscles)
what is skeletal muscle tissues?
voluntary muscle- moves skeleton
-striated pattern or banding pattern
what is cardiac muscle tissue ?
heart- pacemaker controlled
-involuntary we do not control it
- but structure similar like skeletal muscle tissue
what is smooth muscle tissue?
-involuntary do not control
eg. gut, blood vessels
what is nervous tissues?
signal transmission
-brain
-nerves
what happens if we need to repair a tissue?
regeneration : you can replace damage with same type of tissue
fibrosis: build of of collagen fibers eg. picking at a scar, putting extra connective tissue for protection
- clot is replaced by granulation tissue then eventually scar tissue
what are good or excellent regeneration tissues?
epithelial tissue (skin), bone connective tissue (break arm cast for few weeks), areolar connective tissue, dense irregular connective tissue (within skin), blood forming connective tissue
what are some moderate regeneration tissues?
smooth muscles
eg. damage to the gut
what are weak regeneration tissues?
skeletal muscle tissue (inter-cellularly we can repair actin and mysoin quickly but to the tissue the connective tissue around the muscle it is a weak repair, third degree muscle tear), cartilage, dense regular ct NO blood supply
what is an example of no or almost none regeneration of tissue?
cardiac muscle tissue , nervous tissue (particularly the central nervous system)
what happens with age to our tissues?
- epithelia thin
-collagen decreases
-bones, muscles (after 80 loose most muscle mass), and nervous tissue begin to atrophy - poor nutrition and poor circulation lead to poor health of tissues
-decreased healing
