Lecture 4 Flashcards
Why in the respiratory canal does rings of cartilage become c shapes cartilage?
To allow easier movement of the neck
Give an example of a tissue artefact?
Shrinkage during tissue processing
Dust particles introduced during staining process
What are the surfaces of serous membranes called?
Visceral on the inside and parietal on the outside
What are epithelia?
Sheets of contiguous cels, of varied embryonic origin that line all external surfaces of the body and MST internal surfaces.
What is another name for the basement membrane?
Basal lamina
Where d we find simple squamous epithelia?
In the vascuature, Newman’s capsule etc
Where doo we find simple cuboidal epithelia?
Collecting ducts of kidney, pancreatic duct
Where d we find pseudostratified epithelia
Upper respiratory tract
Pseudostratified epithelia function?
Mucus secretin, particle trapping and removal
What does a vascular mean?
It contains no blood vessels
What is dermis?
Dense irregular connective tissue made from collagen and elastin
What are keratinocytes?
Cells found in stratified squamous keratinised epithelium that produce keratin.
What causes psoriasis?
Transit time of keratinocytes from basal layer to stratum corneum reduced from 28-40 days to 2-4 days. resuts in formation of silvery scales as a result of too much stratum corneum
What are melanocytes?
Cells in epidermis that produce melanin. They’re absence results in albinism.
What are langerhans cells
Antigen presenting cells in epidermis responsible for allergic contact dermatitis. They mediate immune responses.
Function of transitional epithelium?
Distensibility and protection of underlying tissue from toxic chemicals.
Function of Clara cells?
Protect bronchioles and act as stem cells for respiratory epithelium.have cytochrome p450 enzymes for detoxification.
What are microfold cells?
Found only in small intestine. They present pathogens to underlying dendritic cells. Can act as a point of weakness for pathogens to enter. E.g salmonella
Cystic fibrosis cause?
Impaired chloride ion transport resulting in no water with mucus from goblet cells.
What does cystic fibrosis affect?
Airways, liver, pancreas, small intestine, vas deferents (infertility), skin (sweat glands)
Function of stereocilia?
Mechanosensing organelles in ear which respond to fluid motion for hearing and balance
How does smoking affect the lungs?
In the early stage mucus layer thickens and cilia die off but these can regenerate in a few days.
At chronic stage goblet cells proliferate to deal with dust in lungs as cilia can no longer do it. Clara cells die and carcinogens induce mutations and malignancy. Fibroblasts lay down scar tissue.
Other cell types regenerate with time but Clara cells never do.
When many cells die underlying carcinogenic tissue can invade.
What is copd?
A combination of acute bronchitis where the airways are chronically inflamed with excess mucus and cough and emphysema where the elasticity of the alveolar sacs is destroyed and they exhaling becomes difficult.
Difference between epidermis and dermis?
Epidermis is the epithelial cells and their basement membrane while dermis is the dense irregular connective tissue underneath. Epidermis is avascular
What are pneumocystis?
Extremely thin alveolar cells for gaseous exchange
Chronic bronchitis?
2 episodes lasting 3 months or more in a two year period
