Chapter 5: Histology Flashcards
how many cells are in the human body?
50 trillion
how many cell types are in the human body?
200
what are the four broad categories of tissues?
- epithelial tissue
- connective tissue
- nervous tissue
- muscular tissue
structure with discrete boundaries that is composed of two or more tissue types
organ
study of tissues and how they are arranged into organs
histology
group of similar cells and cell products working together to perform a specific role in an organ
tissue
4 primary tissues differ from each other in
types and functions of cells, characteristics of the matrix (extracellular material), relative amount of space occupied by cells vs. matrix
matrix composed of
fibers, clear gel called ground substances (aka tissue fluid extracellular fluid (ECF), interstitial fluid, tissue gel
how many germ layers do embryonic tissues have?
3
what gives rise to epidermis and nervous system?
ectoderm (outer)
what gives rise to mucous membrane lining digestive and respiratory tracts, digestive glands, among other things?
endoderm (inner)
what becomes gelatinous tissue called mesenchyme?
mesoderm
wispy collagen fibers and fibroblasts in gel matrix; gives rise to cardiac muscle, bone, blood
mesenchyme
what do histologists use to prevent decay and preserve tissue sections?
fixative
tissue cut on its long axis
longitudinal section
tissue cut perpendicular to long axis of organ
cross section/ transverse section
tissue cut at angle between cross and longitudinal sections
oblique
tissue is rubbed across a slide (i.e blood; liquid tissue)
smear
some membranes and cobwebby tissues are laid out on a slide (ex. areolar tissue; soft tissue)
spread
sheets of closely adhering cells; one or more cells thick; cover body surfaces and line body cavities; upper surface usually exposed to the environment or an internal space in the body; constitutes most glands
epithelia
what is the function of epithelial tissue?
protect, produce and release secretions, excrete waste, absorb, filter substances, sense stimuli
what are the 5 distinguishing characteristics of epithelial tissue?
- polarity, 2. specialized contacts, 3. supported by connective tissues, 4. avascular, but innervated, 5. regeneration
what are the two sides of epithelial tissue?
apical surface and basal surface
what does the apical surface face?
upper free side; top; outwards towards surface or cavity
what does the basal surface face?
attached side; bottom; inwards towards body
tight junctions and desmosomes are both?
lateral contacts
does epithelial tissue contain blood vessels?
no
does epithelial tissue contain nerves?
yes
multiple layers of cells ____________
stratified
one layer of cells
simple
flat cells__________
squamous
cube cells_________
cuboidal
cells taller than they are wide_______________
columnar
most diverse and most abundant type of tissue
connective
what are the functions of connective tissue?
supports, connects, and protects organs; binding of organs, physical protection, immune protection, movement, storage, heat production, transport
4 main classes of connective tissues
connective tissue proper, cartilage, bone, blood
all connective tissues have 3 main elements___________________
ground substance, fibers, cells
what makes up the extracellular matrix?
ground substance and fibers
unstructured gel like material that fills space between cells
ground substance
what does ground substance consist of?
glycosaminoglycans (GAGs), long polysaccharides composed of amino sugars, uronic acid, chondroitin sulfate, proteoglycans, adhesive glycoproteins
what are the 3 types of fibers of fibrous connective tissue?
collagenous fibers, reticular fibers, elastic fibers
most abundant of the body’s proteins, tough flexible and stretch resistant, tendons, ligaments and deep layer of the skin are mostly this
collageneous fibers
thin, highly branched collagen fibers coated with glycoprotein, form framework of spleen and lymph nodes
reticular fibers
thinner than collagenous fibers, made of protein called elastin; allows stretch and recoil
elastic fibers
immature form of cell that actively secretes ground substance and ECM fibers
blast cells
mature, less active form of cell that now becomes part of and help maintain health of matrix
cyte cells
where are fibroblasts?
connective tissue proper
where are chondroblasts found?
cartilage
where are osteoblasts found?
bone
where are hematopoietic stem cells found?
bone marrow
phagocytize foreign material and activate immune system when they sense foreign matter
macrophages