lab 6 Flashcards
what is a tissue?
groups of similar cells that preform a common function.
what are the 4 tissue types?
epithelial, muscle, nervous, and connective tissue
what is histology?
the microscopic study of tissues and organs through sectioning, staining, and examining those sections under a microscope
what are the 3 primary germ layers?
ectoderm, endoderm, and mesoderm. they give rise to different tissues.
what is the ectoderm?
outer layer that gives rise to the outer most layer of skin and the nervous system.
what is the mesoderm?
gives rise to mesenchyme (gelatinous tissue) which in turn gives rise to muscle, blood vessels and CT.
what is the endoderm
gives rise to the mucous membranes in digestive, respiratory, and urinary tracts.
what is epithelial tissue?
forms barriers between things like skin and digestive organs, covers the body (epidermis), lines body cavities, forms glands
what is connective tissue?
supports, protects, and binds tissues or organs together, includes CT proper, cartilage, bone, and blood
what is muscle tissue
contractile tissue to cause movement, lines walls of hollow organs
what is nervous tissue?
found in brain, spinal chord, and nerves. initiates and conducts electrochemical impulses.
what is the two criteria used to classify epithelial tissue?
simple, single layer of cells
stratified, several layers of cells that is classified based on apical layer
what is the apical surface?
free surface (top)
what is the basal surface?
bottom surface, closest to basement membrane
what is squamous cells?
flat cells, scale like. does diffusion. lines the heart and blood vessels
what are cuboidal cells?
shaped like cube nucleus in middle, secreate and absorbs. found thyroid glands
what are columnar cells?
tall and column shaped, with nucleus at the bottom of cell for protection. absorption and secretion. found lining the stomach and intestines
what are pseudostratified columnar epithelium?
single layer of columnar cells that vary in shape and height and all contact basement mem. found in nasal cavities. can have cilia and contain goblet cells for protection
what is keratinized stratified squamous epithelium?
several layers of cells, at apical layer is squamous. the basement layer of cells are mitotic and constantly replace the apical layer. keratinized is found in the skin, for protection in dry area. the keratin protects the cells from heat and damage.
what is nonkeratinized stratified squamous epithelium?
forms linings are vagina, anus, and pharynx. provide protection and serve as a lining or covering for moist internal cavities of the body
what is transitional epithelium?
found in the bladder, allows for cells to slide over each other to expand and contract. at resting, multiple layers of cuboidal cells, as urinary fills cells become flat as they slide. allows for urunary to accomidate pressure changes without rupturing the organ.
what is merocrine?
release fluid products by exocytosis. seen in salivary glands and sweat glands.
what is apocrine?
glands that pinch off portions of the cell as part od secretion, found in mammary glands
what is holocrine?
when the whole cell fills with secretion and bursts, sebaceous glands in hair.
what are the 3 structural features common to all connective tissue?
cells, protein fibres, and ground substance.
what do fibres and ground substance do?
togther they form the extracellular matrix of CT
what do cells in CT do?
creates diversity in CT
where is areolar found?
supports and binds, aka lose CT, found all over body, attaches skin to underlying tissue and fill spcaes between organs to hold them in place.
where is reticular CT found?
filtration.found in liver, spleen, and bone marrow. has reticular fibre.
where is adipose tissue found?
synthesis and storage of lipids, provides insulation and protection. nucleus near edge, and lots of fat droplets. found under the skin and around the heart and eyeballs.
where is dense reg CT found?
composes tendons and ligaments. has tightly packed collagen fibres all going in the same direction.
where is dense irreg CT found?
collagen fibres are thicker and go in all diff directions. found in the dermis, kidney, and muscles. allows for things to stretch.
hyaline cartillage
most common. found at ends of long bones and nose. provides support where flexibility is needed.
elastic cartillage.
has elastic fibres. extremely flexible, found in places that need strength and stretch like external ear and epiglottis.
fibrocartillage
lacks perichondrium. supports and withstands heavy pressure, found in the knee and vertebral discs.
what characteristic of bone is provided by the inorganic salts vs. the organic
materials?
inorganic- responsible for the hardness and resistance.
organic- responsible for strength and flexibility
what are the organic compounds of bone?
osteoid, collagen fibres and ground substance. secreted by osteoblasts.
what are the inorganic compounds of bone?
hydroxyapatite, aka mineral salts. consists of tiny calcium phosphate crystals in and around collagen fibres.
