BL2 Flashcards
What is a organ defined as?
Two types of tissue
How are cells held together? 3
Tight junctions
Desmosomes
Gap junctions
What do tight junctions do?
Form a seal
Function of a desmosomes?
Strengthens
Stops stretching
Function of a gap junction?
Communication
How do cells anchor on the basement membrane? Give examples of where these are found?
Hemidesmosomes
Found in abrasive tissue such as skin epithelium of oral cavity
What’s a focal adhesion?
Attaches cells to basement membrane using their intracellular actin filaments
What’s the structure that the focal adhesion uses to bind to the basement membrane?
Integrins
What’s in integrin?
2 functions
Transmembrane protein that attaches a cells cytoskeleton to the extra cellular matrix
Two main functions are:
Attachment
Signal transduction
To get a tissue culture, how would you separate the cells?
Collagenases
Microdissection
Name the 6 types of cell communication.
Direct contact (gap junctions Autocrine Paracrine Endocrine Synaptic communication Neurocrine
What are the four basic types of tissue?
Epithelial
Muscle
Nerve
Connective tissue
Give four examples of specialised connective tissue?
Adipose Lymphatic Blood Haemopoietic Cartilage Bone
What is an epithelioid ?
Cells that don’t have a surface (epithelial)
Leydig cells in testes
Lutein in ovary
Islets of langerhans
Parenchyma of the adrenal gland
Three specialisations of the apical domain in an epithelial cell?
Microvilli
Stereocilia (sensory hairs and epididymis)
Cilia
Six functions of connective tissue?
1) Connects (duh)
2) Transportation (provides a medium for transportation)
3) Protection (cushions and sheaths)
4) storage
5) Defence
6) Wound healing
What is connective tissue made up of? 3
Cells
Fibres
Ground substances
Types of fibres in connective tissue. 3
Bonus points for function
Collagen - flexible high tensile strength
Elastin- allows stretch and recoil
Reticular - provide a supporting framework/sponge
What’s the ground substance composed of in connective tissue?
Water
Proteoglycans (macromolecule consisting of a core protein to which glycosaminoglycans GAGs are covalently bonded)
A unique GAG is hyaluronic acid
What is hyaluronic acid?
It’s a unique GAG. That binds the proteoglycans together to form a gigantic hydrophilic macromolecule
A GAG is a long chain polysaccharide that covelently binds to a core protein making a proteoglycan
Proteoglycans and water make up the ground substance in connective tissue
What’s makes up the extra cellular matrix?
Ground substance and fibres
What are the two types of connective tissue proper?
Loose
- many cells, spared collagen fibres, abundant ground substance, important role in transport
Dense
- few cells (nearly all fibroblasts)
- many collagen fibres
- little ground substance
Where is loose connective tissue usually found?
Beneath epithelial tissue
Around small blood vessels
Associated with epithelium of glands
What can dense connective tissue be broken down into?
Describe the structures
Composition
Effect on stress
Where is it found
Regular
- parallel bundles of collagen fibres
- designed to withstand stress in a single direction
E.g. found in tendons ligaments and aponeuroses
Irregular
- collagen fibres in different directions
- designed to withstand stress from different directions
E.g. Submucosa of intestines and deep layer of demis
Tendons and ligaments are types of what connective tissue?
Dense regular connective tissue
What do ligaments connect?
Bone to bone
Cells of connective tissue. Fixed or free?
The different types?
Both
Fixed - fibroblasts, melanocytes, mast cells, macrophages, adipocytes, mesenchymal stem cells
Wandering cells
Leucocytes, plasma cells, monocytes, eosinophils, basophils
What do fibroblasts produce?
Fibres and ground substance
Myofibroblasts are modified fibroblasts that contain actin. Responsible for contraction in wound healing
What’s a mast cell?
Function
Structure
Contains multiple granules
- histamine
- heparin
- substances that attract eosinophils and neutrophils
Secretion to substances to attract other cells/reactions
How many types of collagen are there?
Type 1? %? Present in?
Type 2? present in?
Type 3? Know as?
28
Type one. 90%. Fibres arranged into fibres and bundles. Tendons, organ capsules, skin dermis
Type 2. Fibrils not fibres. Hyaline and elastic cartilage
Type 3. Form fibres round muscle, nerve and lymphatic tissues and organs. Known as reticulate
Collagens structure is ?
How is it produced?
Triple helix of alpha chains
Procollagen is produced inside the cell and assembled outside. Vitamin C is needed for production of procollagen - scurvy
What’s Marfan syndrome?
- > type of disease
- > Pathophys
- > Side effects
Autosomal dominant disorder
Fibrillin gel is abnormal-> elastic tissue is abnormal. = more elastic tissue
Sufferers are tall, joint dislocations , and risk of catastrophic aortic rupture(aneurysm)
What ghrelin do?
Leptin?
Ghrelin = appetite stimulator. Age gender and blood glucose affect ghrelin and is used to stimulate hunger
Leptin is stored and secreted by fat when you eat a meal. It tells the brain you are full
What are the three general types of CT?
1) CT proper (loose and dense)
2) Specialised CT (blood&Lymph)
3) Supporting CT (cartilage,bones, bone marrow)
CTs are made up of cells. Name 3 of the 5 cell types which are fixed.
- Fibroblasts
- Fixed macrophages
- Mast Cells
- Adipose cells
- MELANOCYTES
What are the 3 types of fibres in CTs?
Reticular
Collagen
Elastic
What is senescence?
The process of age deterioration
What is apoptosis?
Programmed cell death
What is necrosis?
Un-planned cell death
Why do necrotic cells swell and burst?
Failure of the Na/K ATPase
What are the limits of pH?
6.8 to 7.8
What organs are usually effected first due to pH changes
lungs
kidneys
liver
What is shock?
Global cellular and tissue hypoxia/ reduced o2 delivery
If a compartment has a high osmolarity… what does that mean?
It has a high conc of SOLUTES and PROTEINS
just proteins is called oncotic pressure
What protein is the most abundant in the body?
HARD- where is it made?
Albumin
Liver
/\ in liver cirrhosis. Less albumin in blood -> fluid build up in interstitial space
Whats the difference between collagen fibres and reticular fibres?
Collagen - FLEXIBLE with high TENSILE STRENGTH
Reticular - SUPPORTING FRAMEWORK
How do you identify between loose and dense connective tissue? )break it down(
Loose - more cells, sparse collagen fibres, lots of ground substance
Dense - few cells (fibroblasts), many collagen fibres, not much ground substance
What CT is an aponeurosis made up of?
Dense Regular CT
What is Fibrillin?
Componant that is needed to for elastin
Produced by fibroblasts
