Diversity of Cells Flashcards
What must tissue be impregnated with and why?
A support material such as wax to maintain structure of cells in thin slice
Unnecessary for cell smears
Why must tissue be sliced thinly to view under microscope?
To allow light to penetrate tissue
How is tissue treated with wax?
First dehydrated, put in organic solvent, and placed in hot wax for several hours
How are thin tissue sections cut?
Using a microtome
Explain process to prepare tissue for viewing
Thin sections put on slides, wax washed away and tissue is rehydrated
What are artifacts?
Small changes in the tissue caused by the preparation process
What is haematoxylin?
A basic dye which binds to acidic molecules and stains them purple
eg. the nucleus
What is eosin?
An acidic dye which binds to basic molecules and stains them pink
eg. proteins in cytoplasm
Why are epithelial cells suited to lining body cavities?
Form sheets of cells due to binding of cells together with little space between them
What is the basal lamina?
Layer of extracellular matrix components to which all of the epithelial cells are attached
Are epithelial cells non-vascular?
Yes
Oxygen and nutrients must diffuse across basal lamina
Are epithelial cells polarised?
Yes
The apical and basal ends are different
Give an example of an organ made of solid epithelial cells
the liver
List 7 different functions of epithelial tissues
Mechanical barrier (skin)
Chemical barrier (stomach lining)
Absorption (intestine lining)
Secretion (salivary gland)
Containment (urinary bladder lining)
Locomotion by movement of cilia (oviduct)
Minor localised functions (sensation eg neuroepithelium which makes up taste buds and contractility eg myoepithelial cells)
List the three shapes of epithelial cells
Squamous (flat)
Cuboidal (cube)
Columnar (column)
What does a simple layer of epithelial cells mean?
Layer only one cell thick
What does it mean if an epithelial tissue is stratified?
Layer is two or more cells thick
What does it mean if an epithelial tissue is pseudostratified?
Seems as if tissue has multiple layer but all cells are directly connected to basal lamina
What do glandular epithelial cells make?
Secretory products eg. sweat, hormones, mucous
Whats the difference between an endocrine gland and an exocrine gland?
Endocrine gland - product secreted from basal end of cell and released into vascular system (ductless glands)
Exocrine gland - product secreted from apical end of cell into lumen of internal space, duct, or body surface (ducted gland)
Name the three types of connective tissue
Soft connective tissue - tendons, ligaments, dermis of skin
Hard connective tissue - bone and cartilage
Blood and lymph
What makes up the extracellular matrix?
Fibres - collagen, reticular, and elastic fibres
Ground substance - unbranched polysaccharide molecules called GAGs
Tissue fluid
What are the cells in the connective tissue?
Fibroblasts - produce and maintain extracellular matrix
Adipose cells
Osteocytes - bone cells
Chondrocytes - cartilage cells
Name the three types of cartilage
Hyaline
Elastic
Fibrocartilage
Recognisable from extracellular matrix
Where is Hyaline cartilage found?
articular surfaces
tracheal rings
epiphyseal growth plates
costal cartilage
What is cortical bone and where is it found?
Dense outer cortex of bone
What is cancellous/trabecular bone and where is it found?
Meshlike bone filled with pockets found inside bones
Name the three types of muscle tissue
Smooth
Skeletal
Cardiac
Describe Smooth muscle tissue
Often found in organs, not consciously controlled, no visible striations
Individual fibre long, cigar shaped nuclei
Describe Skeletal muscle
Consciously controlled, visibly striated
There are exceptions to both
Contain more than one nucleus located at periphery of cell, long
Membrane called sarcolemma
Does cardiac muscle have striations?
Yes, but fainter than in skeletal muscle
Describe cardiac muscle
Shorter fibres than skeletal muscle, form complex network, single nucleus at centre, intercalated discs present where cells meet
What makes up nervous tissue?
Neurons and glia (support cells)
Are there more neurons or glia in CNS?
Glia
What tissue protects neurons in CNS?
Meninges
What tissue protects axons in PNS?
Epineurium
What is a multipolar neuron?
A neuron with many dendrites and one axon
What is a bipolar neuron?
Neuron with one dendrite and one axon
What is a pseudounipolar neuron?
Neuron with an axon which has split in two, extending towards spinal cord and peripheral nervous system
What is an astrocyte?
a glial cell which supports neurons, transports ions, and induces blood brain barrier
What is an oligodenrocyte?
A glial cell which produces myelin in CNS
What are microglia?
Cells which provide immune surveillance
What do a schwann cell do?
Produce myelin and support axons of PNS neurons
