cells to systems 1 Flashcards
(95 cards)
four basic types of tissue
1) nervous tissue
2) connective tissue
3) muscle tissue
4) epithelial tissue
List the 10 body systems and whether generalised or localised
1) musculo-skeletal - G
2) cardiovascular - G
3) immune and lymphatic -G
4) endocrine - L
5) nervous - G
6) integumentary system -G
7) respiratory - L
8) digestive - L
9) renal - L
10) reproductive - L
what is a peroxisome
contain enzymes that detoxify certain toxins
what does the body consists of and what are the percentages
water (60%), protein (17%), lipids (15%), minerals (inorganic acids and electrolytes 5%), nucleic acids (2% ) carbohydrates (1%)
methods of examining tissues
1) fixation (e.g. formalin) - treatment with chemical that stops enzymatic activity, freezes the tissue at state of fixation
2) embedding (e.g. paraffin wax) - put into solid medium so can cut sections of tissues
3) sectioning (~ 5 μm thick) - cut with special scissors
4) staining, e.g. haematoxylin and eosin (H&E) - combination most commonly used stains nucleus and ribosomes - mRNA
5) mounting - put coverslip on it using mounting medium that is glow like substance that is clear and goes hard so get permanent preparation
cells when end in -blast and -cyte what does it mean
- blast - not a fully differentiated cell may have functions of its own but still has potential to further differentiate
- cyte - fully differentiated
what are the two main types of extracellular material (connective tissue) and the subtypes
1) amorphous - shapeless
2) fibrous - 3 types
1. collagen
2. reticular
3. elastic
describe the characteristics of collagen, reticular and elastic fibres how strong, what colour, what colour stain
strong, flexible, white, eosinophilic orange in verhoeffs stain, type 1 but can be varied
ret - fine network, poorly stained H&E back in reticulin stain
elas - stretchable, elastic (elastin), yellow, eosinophilic and black in verhoeffs stain
connective tissue proper functions
- support - in abdomen help gastrointestinal tract, spleen, kidneys
- protection - capsule against mechanical injury for lymph nodes
- connections within locomotor system - tendons connect muscle to bone ligaments connect bone to bone
- holds tissues together - reticulum fibres hold cells together
- energy storage - 2 ways, 1 in elastic tendons and ligaments, 2 in fat tissue
connective tissue proper types
• loose (higher ratio of cells to fibres) • adipose (many fat cells) • dense (lower ratio of cells to fibres) - regularly arranged - irregularly arranged eg - horse skin
list the 8 cells associated with connective tissue
1) mesenchymal cells
2) fibroblast
3) fibrocyte
4) macrophage
5) fat cell - adipocyte
6) mast cell
7) plasma cell
8) melanocyte
where is mesenchymal cells found, their shape and nucleus
- in embryonic tissues and some adult tissues, type of stem cell
- stellate (star-shaped) - many cytoplasmic processes
- oval/round nucleus
fibroblast shape, nucleus, where found and function
- stellate or spindle-shaped
- ovoid nucleus
- abundant basophilic cytoplasm - lots of ribosomes as producing collagen
synthesizes and secretes collagen and other extracellular matrix components - differentiates into fibrocyte
fribrocyte shape, nucleus, cytoplasm, function
- small flattened elongated cell
- elongated nucleus
- very little cytoplasm - hard to distinguish
- less active in secretion than fibroblast as stop synthesising
- Role is to maintain connective tissue structure
mast cell where found, cytoplasm with what within, function
- scattered, in low numbers in most connective tissues (often close to blood vessels)
- cytoplasm filled with granules (basophilic so stain blue) containing heparin (anticoagulant), histamine (increases
blood vessel permeability), serotonin (vasoconstrictor) and proteases - degranulate when tissue damaged promote inflammatory reaction
what are the two types of epithelial tissue and their function
- Layers or sheets - surface covering / lining – barriers / absorption / secretion - single layer simple, multi layers stratified - always a basement membrane, may not always see
- Glands - secretion
what are the 5 types of simple epithelial layers and their shapes and nuclei and example of where found
1) squamous - nuclei squashed, scale or plate like (flat), line duct and capillaries
eg - serous membrane of internal organs
2) cuboidal - cube-shaped cells, nucleus fills up most of the space, appear perpendicular to the surface of epithelium
eg - secretory cells of thyroid glands
3) columnar - tall cells, nucleus tends to be towards the base of teh cell, can be elongated
eg - secretory cells of prostate glands
4) pseudostratified -tall and short cells which rest on basement membrane, nuclei at different levels so looked stratified
eg - in respiratory tract
5) transitional - appears stratified but pseudostratified according to some peeps
eg - urinary bladder
stratified layer of epithelial how named and what are the types
multi layers present so not all cells attach the basement membrane
reference to the shape of the cells located on the surface
1) squamous - may undergo keratinization eg the skin
2) cuboidal
3) columnar
2) & 3) often seen in ducts of glands
what are the 3 surfaces for epithelial cells and list the structural specialisation
1) apical surface
1. cilia
2. microvilli
3. stereocilia
2) lateral
1. interdigitation
2. junctional complex
3) basal
1. basal striations
2. basement membrane
3) hemidesmosomes
what are stereocillia, interdigitation and junctional complex
large microvilli; non-motile; increase surface area for absorption / secretion;
e.g. in epithelial cells of epididymis
interlocking structure
occluding type
- tight junctions (zonula occludens) adhering type - seals them off - waterproofing
- desmosomes (zonula / macula adherens) communicating type - like super glue between cells eg in heart muscle
- gap junctions (nexus) - communication junctions, open channel between cells
what are basal striations and hemidesmosomes
- invaginations or infoldings of basal surface of cells; to increase surface area for active transport of substances into and out of cell
attach cell to extracellular matrix
development of endocrine and exocrine glands
both arise similarly as localised proliferation of epithelial
endocrine - lose connection to surface
exocrine - retain connection to the surface
exocrine glands what comprised of and how they secrete
Exocrine glands comprise one or several secretory units which are connected to a surface(of tissue, duct, lumen etc.) by a system of ducts - thus their secretory product is discharged onto the body surfaces or into visceral lumina. These glands produce enzymes, milk, sweat and other secretions.
morphology of exocrine glands what are the two opposites
simple - one or more secretory units within single unbranched duct
compound - multiple secretory units within system of branched ducts
tubular - secretory unit in shape of tube - cuboidal
alveolar (acinar) - secretory unit in shape of sphere
tubuloalveolar - both types of secretory units present