Body Log Flashcards
How do you prepare light microscopy?
Preserve in formalin
Used melted paraffin/wax to make it hard
Cut slices with a microtome
Stain with haemotoxylin and eosin
What is a cryasection?
A frozen sample made using a crystal
What is polarised light microscopy?
Shows crystals like in gout- can show difference between gout and pseudo gout
What is autoradiography?
Photograph taken to see molecules with a radioactive marker
TEM
Uses an electron beam generated in a vacuum Looks at dead tissue Passes through tissue Very small wavelength X 250000 microscopy
SEM
Electrons are reflected to give a 3D image
Freeze fracture
Freeze tissue to -160 and hit with knife edge
Immunohistochemistry
Determines protein or epitope is present on the cell surface
Indirect affects antibody attaching to the epitope
Immunofluorescence attaches antibody tag
What is an ultrasound?
High frequency ultrasound wave = low wave length = good resolution
Low freq= high wave length= low resolution
Types of cell junction
Tight junction Desomosomes Gap junction Hemidesomosomes Focal adhesions Integrins
Tight junctions
Tightly connected to adjacent cells via lateral domain
For a seal to stop molecules passing through, molecules must pass through the cell so forms a partially permeable barrier
Desomosomes
Cadherins interlock and connect cells
Intermediate fibres are also found on inside to keep the cells together and prevent stretching
Gap junctions
Allow cell communication, connexons form channels for molecules to go through
Hemidesomosomes
Half a desomosome
Found in cells/ tissues subject to abrasion links the cell to basal lamina
Focal adhesions
Anchor intracellular actin filaments to the basement membrane uses integrins as transmembrane proteins
Focal adhesions
Anchor intracellular actin filaments to basement membranes
Integrins
Attach to cell and extracellular matrix
What is the basement membrane?
Layer between epithelial cells and connective tissue and consists of basal lamina and reticular fibrils
Types of cell to cell communication
Autocrine
Paracrine
Endocrine
Neurocrine
What is autocrine communication?
Cell molecule releases molecules which bind to receptors on the cells own surface
What is paracrine communication?
Substances are secreted to surrounding cells
What is endocrine communication?
Secrete hormones into the blood
What is neurocrine communication?
Neurone secretes hormones into the blood
Apical domaine
Can be specilaised with microvilli, stereovili and cilia
What is osmolality
Concentration of solutes and proteins per kg
What is osmolarity?
Conc of solutes and proteins per litre of solution
What is oncotic pressure?
Oncotic pressure is conc of proteins only
What is normal osmolaity?
285-295 mOsmol/kg
Hypotonic vs. Isotonic v. Hypertonic
Hypotonic- water moves into the cell
Isotonic- water moves in and out of the cell equally
Hypertonic- water moves out of the cells
Limits of survival pH
6.8-7.8
Water in 70 kg human
42 litres
Extracellular water in 70kg human
14 litres
Intracellular water in 70kg human
28 litres
Volume of blood
5l
3 layers of mucous membranes
Epithelium
Lamina propria
Muscularis mucosae
Examples of serous membranes
Peritoneum
Pleural cavity
Pericardium
What is the skin made of?
Stratum cornermen
Granular layer
Prickle layer
Basal layer
Skin functions
Protection Sensation Thermoregulation Excretion and secretion Immunity Endocrine- produce vitamin C Growth
Common skin conditions
Acne
Psoriasis
Eczema
What is acne?
Inflammation of pilosebacous follicles with hormonal causes- black and white heads
Can be inflammatory
Due to bacterium and sebum production
What is psoriasis?
Hyperproliferation of keratinocytes- genetic and environmental cause- stress and drugs. Can be inflammatory. Due to bacteria and sebum production
What is eczema?
Itchy, dry scaly skin. Itching leads to scratching which leads to thickness of skin . Use antihistamines and steroids
Simple squamous epithelium
Thin flat cells
Called endothelium lining blood vessels and mesothelioma when part of serous membrane
What are the four basic tissue types?
Epithelial
Muscle
Nerve
Connective tissue
Functions of connective tissue
Connects Transports Protects Storage Defence Wound healing
Specilaised connective tissues examples
Blood Bone Haemopoetic Cartilage Lymphatic Adipose
Type 1 collagen
Gives CT the strength and forms fibrils
Fibroblasts secrete procollagen
Reticticular fibres
Type iii collagen
Gives a supporting framework and in lymphatic vessels and tissues
Elastic fibres
Allow tissues to stretch and recoil. Elastic fibres are surrounded by microfilaments called fibrillin
Cells in CT proper
Fixed -Fibroblasts- synthesis and secrete ground substance, mast cells melanocytes, mesenchymal stem cells
Wandering- leukocytes, plasma cells, eosinophils, basophils and monocytes
Loose CT proper
Abundant cells and watery ground substance, sparse collagen fibres, found beneath the epithelia around small blood vessels. Superficial layer of dermis.
Dense CT proper
Few cells, lots of fibroblasts, lots of collagen fibres densely packed. Regular is where collagen fibres are arranged in parallel bundles to withstand stress in one direction. Irregular is when collagen fibres are arranged in various directions
Ground substance
Viscous, clear substance with high water content and made of proteoglycans . Proteoglycans are large macromoleculeswith core glycosaminoglycans attached via .
