Glands Flashcards
What is an exocrine gland?
-A gland which secretes to the outside of the body via ducts
Define glandular tissue
-Type of epithelia cell (an aggregation of cells) which are specialised for secretion
What is an endocrine gland?
A ductless gland which secretes into the bloodstream
What type of glandular structures are there?
- Unicellular/multicellular
- Simple/compound
- Acinar/tubular
- Coiled/branched
Where do unicellular gland secrete onto?
Epithelial cells
What is endocytosis?
- Cell makes contact with extracellular material
- Cell surrounds material
What is transepithelial transport?
- 1)Endocytosis at one membrane
2) Transport vesicle
3) secretion/exocytosis at opposite membrane
Describe the secretions of serous glands
- Watery and free of mucus
- Often contain enzymes
- Stain eosinophilic with H+E
Which epithelia cells continually regenerate?
- Respiratory
- Digestive
- Urinary
- Skin
Describe merocrine secretion
- Membrane bound vesicle approaches cell surface
- Fuses with plasma membrane
- Contents released into extracellular space
- PM transiently larger
- Membrane retrieved
Describe apocrine secretions
- Non-membrane bound structures approach pm
- contacts apical membrane and pushes up
- membrane surrounds droplet and pinches off
- membrane added to regain size
Describe holocrine secretion
-The cell disintegrates and releases the whole cell contents
What are the three salivary glands and what are their secretion types?
- Parotid ->serous
- Sublingual ->mucus
- Submandibular ->both (mucus pushes serous to edge of cell forming a cresent)
What is an adenocarcinoma?
-Malignant neoplasm from glandular epithelial cells
Why is glycosylation of proteins important and where does it occur?
- Adds biochemical specificity to the protein
- Occurs in the golgi
How do proteins migrate through the cisternae of the golgi?
- Swelling at the ends of the cisternae
- Buds off into vesicles
- Join the next membrane disc
What is the fate of the vesicles produced from the golgi?
- Enter regulatory secretory pathway
- Enter constitutive pathway
- Remain in the cell as lysosomes
- Enter the glycocalyx of the pm
What does the glycocalyx of the pm do?
- Adds biological specificity
- Adherence of cell
- Communication
- Protection - lubrication
- Division
What is the purpose of secretion and how is secretion controlled?
- Communication
- Regulation of pathways
- Lubrication
- Protection
- Nervous and endocrine hormonal control
