Histology: Diversity of Cells and Their Functions Flashcards
how is a tissue fixed and preserved
a chemical that cross-links proteins i.e. formalin is used
describe the process of creating a tissue slide
- tissue is thinly sliced
- tissue dehydrated and put in organic solvent and hot wax
- microtome cuts thin slices
- tissue put on slides, wax is washed out, tissue rehydrated and stains are put in
what are artefacts
distortions/changes from original tissue
what are the most common stains
Haematoxylin and Eosin (H and E)
Haematoxylin is _ and stains _ molecule turning them _
basic, acidic, blueish-purple
Eosin is _ and stains _ molecules turning them _
acidic, basic, pinkish-red
what usually stains with eosin
cytoplasm
what are the 4 basic tissue types
- epithelium
- muscle
- connective
- nervous
what do epithelial cells do
cover body surfaces/line hollow organs and form many glands
what are the roles of connective tissue
- development, growth and homeostasis of tissues
- energy storage (i.e. fat)
what is the role of muscle cells
generate force by contracting
what does nervous tissue consist of
neurons and supporting cells
what is the role of nervous tissue
control function and allow rapid communication wihtin the body
what is a basal lamina
layer of extracellular matrix components that epithelial cells are attached to
are epithelial cells vascular or non-vascular
non-vascular
where do epithelial cells get their nutrients
from capillaries in underlying tissues - nutrients diffuse across basal lamina
what are the functions of epithelial cells (8)
- chemical barrier
- locomotion
- absorption
- secretion.
- mechanical barroer
- containment
minor - sensation and contractility
what are the 3 epithelial cell shapes
- columnar
- squamous
- cuboidal
how many layers of epithelial cells in a:
- simple
- stratified
- pseudostratified epithelium
- simple - 1
- stratified - 2+
- pseudostratified - looks like multiple but all cells are in contact with basal lamina
what are the 3 specialisations of epithelium
- keratinised
- villi
- microvilli (brush border)
what specialised cell may appear in epithelium and what is its function
- goblet cell - single cell, mucous gland
what does glandular epithelium do
produce secretions i.e. milk, mucous, hormones, enzymes, oil
describe an endocrine gland
- product secreted towards basal end of the cell
- ductless
- product distributed in vascular system
describe an expcrine gland
- product secreted towards apical end of cell
- into lumen of an internal space, a duct or a body surface
- ducted
what are the 2/3 types of connective tissue and examples of each
- soft - dermis of skin, tendons, ligaments, mesentry
- hard - bone and cartilage
- lymph and blood - specialised form
what does connective tissue consist of (2)
- cells
- extracellular matrix
what is the extracellular matrix of connective tissues made of
- fibres
- ground substance
- tissue fluid
describe ground substance
jelly like substance with no particular shape containing glycosaminoglycosides (GAGs) - most are bound to protein cores making glycoproteins
what types of cells may be a part of connective tissue
- osteocytes
- adipose
- fibroblasts
- chondrocytes
where would you find
- adipose cells
- chondrocytes
- osteocytes
- adipose cells - in many tissues particularly adipose
- chondrocytes - cartilage
- osteocytes - bone
what is the type of connective tissue determined by
type and amount of the two components (cells and extracellular matrix)
what are the two types of soft connective tissue
loose and dense
describe loose connective tissue
loosely packed fibres seperated by lots of ground substance with many cells
decsribe dense connective tissue
densely packed collagen bundles, can be regular (fibres run the same way) or irregular (fibres run opposite ways)
what are the 2 types of hard connective tissue
- cartilage
- bone
desrcibe cartilage
- strong, flexible, compressible, semi-rigid as highly hydrated with ground substance
- non-vascular, gets nutrients from adjacent tisses, diffuse through matrix
what are the 3 types of cartilage
- hyaline
- elastic
- fibrocartilage
where is hyaline cartilage found
- articular surfaces
- tracheal rings
- costal cartilages
- epiphyseal growth plates
what are the 2 types of bone
- outer shell
- ends
describe the outer shell of bones
dense cortical bone, makes diaphysis
describe the epiphysis of bones
cancellous with trabecular - fine meshwork or red bone marrow with supporting rods
what are haversan canals
penetrate bone for blood vessels and nerves
what are the 3 types of muscle tissue
- smooth
- skeletal
- cardiac
describe smooth muscle
involuntary/non-striated, mainly found in organs, elingated and spindle shaped fibres with a cigar shaped nucleus
describe skeletal muscle
voluntary/striated, giant, multinucleated - elongated and at periphery, cylindrical,
what is the cell memebrane of a muscle cell called
sarcolemma
describe cardiac muscle
less prominent striations, form majority of heart chamber walls, branch to form networks, single nucleus at centre, shorter than skeletal, contain intercalated discs
what are intercalated discs and why does cardiac muscle contain many
- sites of attachment between adjacent cells
- many for mechanical integrity
what is nervous tissue surrounded by and what is this called in the
- CNS
- PNS
connective tissue coat
- CNS - meninges
- PNS - epineurium
what are the 3 types of neurons
- multipolar
- bipolar
- pseudounipolar
describe a multipolar neurone
one axon, many dendrites
describe a bipolar neruone
one axon, one dendrite
describe a pseudounipolar neurone
short process with and axon in both directions
what glial cells are in the CNS
- astrocytes
- oligodendocytes
- microglia
what glial cells are in the PNS
- schwann cells
what are astrocytes function
support, allow ion movement, induce BBB
function of oligodendrocytes
produce myelin in the brain and spinal cord
function of microglia
immune surveillance
function of schwann cells
produce myelin and support axons
