Tissues & Integumentary System Flashcards
histology
study of tissues
tissues
cluster of cells similar to each other & work together to perform function
name the 4 types of cells
epithelial, connective, muscle, nervous
how many different types of cells in body
200
somatic cell
all body cells except sex cells
histology
microscopic study of tissue appearance, organization, function
epithelial tissue function/place
sheets of cells cover exterior surface, internal cavities, forms certain glands
connective tissue function
binds cells & organs & functions in protection, support, integration of all body parts
muscle tissue function; name the 3 different types
responds to stimulation & contracting to provide movement; skeletal (voluntary), smooth, cardiac
nervous tissue
excitable, allows electrochemical signals as nerve impulses that communicates w/rest of body
zygote
fertilized egg
totipotent
each embryonic cell has capacity to to divide, differentiate, develop into new organism
ectoderm function
“outer”; epidermis, glands on skin, some cranial bones, pituitary & adrenal medulla, nervous system, mouth, anus
mesoderm
“middle”; connective tissue, bone, cartilage, blood, endothelium of blood vessels, muscle, synovial membranes, serous membranes lining body cavities, kidneys, lining of gonads
endoderm
“inner”; lining of airways/digestive system except mouth & rectum/anus, glands
tissue membranes
thin layer of sheet of cells that cover outside of body; connective & epithelial
connective tissue membrane
encapsulate organs & line movable joints
synovial membrane
connective tissue that lines freely movable joint so they can be lubricated & move freely
what attaches to connective tissue?
serous & mucous membranes (types of epithelial membranes)
examples of synovial membranes
shoulders, elbow, knee
synovial membranes release what type of fluid to be a natural lubricant
hyaluronan `
serous membrane
epithelial membrane; line cavities not open to outside, cover organs
cutaneous membrane (cutaneous membrane)
squamous epithelial membrane on top of connective tissue, dead keratinized cells are on top of this
basal lamina
mix of glycoproteins & collagen; attachment site for epithelium & connective tissue
reticular lamina
secreted from connective tissue; basal lamina attaches to this and forms basement membrane
epithelial characteristics:
highly cellular, avascular (must get nutrients from diffusion/absorption), capable of secretion
name the 3 ways epithelia is connected
tight junction, anchoring junction, gap junction
tight junction
no extracellular space between them, which means they are selective barrier since no substance can move between them
anchoring junction
3 types; desmosomes, hemidesmosomes, adherens. these junctions influence shape/folding of epithelial tissue
gap junction
intercellular passageway between membranes of adjacent cells to facilitate movement of small molecules; allows electrical & metabolic coupling of cells
name the 3 cell shapes
squamous (flat/thin), cuboidal (wide/tall), columnar (rectangular, taller than wide).
name the 2 descriptive terms for cell layers
simple (1), stratified (multiple)
simple squamous epithelium appearance & example
thin scales; ex. endothelium, alveoli
endothelium
epithelial tissue that lines vessels of lymphatic & cardiovascular system
mesothelium
simple squamous epithelium forms surface layer of serous membrane that lines body cavities & internal organs
simple cuboidal epithelium
active in secretion & absorption of molecules, lining of kidney tubules & ducts of glands
simple columnar epithelium
nucleus elongated; digestive tract & female reproductive
pseudostratified columnar epithelium
single layer of irregularly shaped columnar cells; found in respiratory tract
where is stratified epithelium
epidermis, lining of salivary ducts, male urethra, bladder
whats the most common type of stratified epithelium in the body
stratified squamous
endocrine gland
ductless gland that releases secretions directly into surrounding tissues & fluids; ex. hormones
exocrine gland
secretions leave through a duct that opens directly/indirectly to external environment; ex. mucous, sweat, saliva, breast milk
name the 2 types of exocrine glands
serous (watery, blood-plasma like secretions rich in amylase)
mucous gland (watery rich in glycoprotein mucin)
name the 3 ways a cell releases secretions
merocrine, apocrine, holocrine
merocrine secretions
most common type; secretion enclosed in vesicles that move to surface & released by exocytosis
apocrine secretion
secretion pinches off from cell & release; armpits & genitals release fatty secretions that bacteria breaks down=odor
holocrine secretion
rupture & destruction of entire gland cell; ex. oils on skin & hair
stratum basale
deepest epidermal layer, attaches epidermis to basal lamina
function of connective tissue
support/connect other tissues; transport fluid, nutrients, waste, and chemical messengers
mesenchyme
first connective tissue to develop in embryo
whats the second type of connective tissue to form in embryo
umbilical cord (mucous connective tissue)
what is the most abundant cell in connective tissue proper
fibroblast,
adipocytes
cells that store lipids as droplets that fill most of the cytoplasm; 2 types (white & brown)
mesenchymal cell
multipotent stem cell; can turn into any type of connective tissue
macrophage cell
type of blood cell; immune system & release small proteins that act as chemical messengers
mast cell
contain signals for histamine & heparin
collagen fiber
made from fibrous protein; flexible, strong, give ligaments & tendons resilience
elastic fiber
return to normal size after being stretched & compressed, in skin & vertebral column
reticular fiber
in liver & spleen; anchor & provide support for parenchyma (functional cells, blood vessels, nerves)
what is ground substance & what is it made of?
clear matrix of tissue; polysaccharides & proteins
where is loose connective tissue
between many organs, acts to absorb shock & bind tissues together; allows salts etc to diffuse through to adjacent tissues
adipose tissue
loose connective tissue that stores fat for energy & insulation
areolar tissue
contains all cell types; fills space between muscle fibers, surrounds blood & lymph vessels, supports organs
reticular tissue
mesh-like; supports framework of soft organs such as lymphatic tissue, spleen, liver
dense connective tissues
more collagen fibers than loose connective; two major categories (regular & irregular)
regular connective tissues
run parallel adds strength; ligaments & tendons
irregular connective tissue
direction of fibers is random & adds strength in general but not in one specific direction; dermis of skin is example
what are the 3 main types of cartilage
hyaline, fibrocartilage, elastic
hyaline cartilage
most common; short & dispersed collagen fibers; smooth; found in rib cage & nose
fibrous cartilage
tough & has thick bundles of collagen fibers; menisci in knee
elastic cartilage
contains elastic as well collagen & proteoglycans; gives rigid support; ear lobes
what is the hardest connective tissue
bone; contains mostly collagen fibers
skeletal muscle
long cylindrical fiber, striated; voluntary, produce heat; attached to bones & entrance points of body
cardiac muscle
short, branched, striated; pumps blood
smooth muscle
short, spindle-shaped, no striation; involuntary movement, moves food/respirations/secretions; walls of major organs/passageways
how much of your body is made up of skeletal muscle
40%
nervous tissue
excitable & capable of sending & receiving electrochemical signals that provide body w/info
what are the 2 classes of nervous tissue
neuron & neuroglia
intercalated discs anchor cells
cardiomyocytes
astrocytes
regulation of ion concentration; uptake/breakdown of neurotransmitters & formation of blood-brain barrier
microglia cells
protect nervous system against infection; related to macrophages
oligodendrocyte
produce myelin in CNS
Schwann cell
produces myelin in PNS
which proteins are responsible for muscular contraction
actin & myosin
what is the cell body of a neuron
soma
function of myelin
insulate axons & increase action potential speed
angiogenesis
growth of new blood vessels results in vascularization of the new tissue know as granulation tissue
NSAIDS work to reduce pain by inhibiting synthesis of what pain causing hormone
prostaglandins
what are the 5 layers of the epidermis
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
dermal papilla
superficial portion of the dermis; strengthen connection between dermis & epidermis
basal cell
cuboidal-shaped stem cell
merkel cell
function as receptor; stimulates sensory nerves that brain perceives as touch
melanocyte
produces melanin
stratum spinosum
spiny; protruding cell processes that join cells via desmosome (strengthens cell bonds)
langerhans cell
functions as macrophage
stratum granulosum
grainy appearance due to keratinocytes
which two proteins make up stratum granulosum
keratin, keratohyalin
stratum lucidum
smooth, translucent layer of epidermis; only in palms, soles, digits; keratinocytes in this layer are dead/flat; contain eleiden (protein rich in lipids, provides barrier to warer)
stratum corneum
most superficial layer of epidermis; 15-30 layers of dead cells; protection; replaced by cells from stratum granulosum during 4 week periods
dermis
contains blood & lymph vessels, nerves, hair follicles, sweat glands; made of 2 layers produced by fibroblasts
papillary layer
loose, areolar connective tissue; collagen & elastin fibers form loose mesh; projects into stratum basale of epidermis
reticular layer
dense, irregular connective tissue; well vascularized & nerves
elastin fibers
provide elasticity to skin
collagen fibers
bind to water to strengthen skin
hypodermis
connect skin to underlying fascia of bones & muscles; well vascularized, loose, areolar connective tissue & adipose tissues; fat storage & insulation & cushioning
how does the skin function as part of the immune system
by removing bacteria by continuously replacing epidermal cells
name of gland that produces sweat
sudoriferous gland
eccrine gland
produces hypotonic sweat for thermoregulation; coiled glands deep in the dermis; exocytosis release
sebaceous gland
oil gland; found mostly w hair follicles; generate sebum (mix of lipids) to lubricate dead/dry layer of keratinized cells; also antibacterial; stimulated by hormones
epidermal hairs are controlled internally by
arrector pili muscles
meissner corpuscle
responds to light touch
pacinian corpuscle
responds to vibration
basal cell carcinoma
affects mitotically active stem cells in stratum basale of epidermis; most common on head, neck, arms, back;
squamous cell carcinoma
affects keratinocytes of stratum spinosum & presents as lesions on scalp, ears, hands; second most common;
melanoma
uncontrolled growth of melanocytes; mole; most fatal
