Exocrine And Specialised Glands- Lec 7 Flashcards
Where is the parotid gland found?
In front of the lower ear
Give 2 examples of where exocrine and endocrine glands coexist
Liver and Pancreas
Describe the parotid gland
An entirely serous exocrine gland of the acinar type.
Where is the sublingual gland and what does it secrete?
Under the tongue. Secretes almost complete mucous
Where is the submandibular gland found and what does it secrete?
Under jaw. Secretes mostly serous and some mucous
What’s the difference between Exocrine and Endocrine glands?
Exocrine are ducted and usually secrete enzymes or lubricants
Endocrine are non- ducted and secrete directly into the blood stream. They usually secrete hormones.
What is the difference between a simple and a compound gland?
Simple glands contain a straight unbranded duct.
Compound glands have ducts that branch repeatedly.
What type of saliva does the Parasympathetic nervous stimulus produce?
Large vol. of watery saliva rich in enzymes
What type of saliva does the sympathetic nervous stimulus produce?
Small thick secretion of saliva rich in mucous
What type of stimulus controls saliva secretion
Neural stimulus
Why does the liver stain very red in the H and E stain?
Eosin is responsible for staining proteins red therefore the liver makes lots of proteins
Name the 3 types of vessels
Continuous
Fenestrated
Sinusoid
Describe briefly the structure of a continuous vessel and where it is found
Made up of an endothelial layer wrapped in a basement membrane layer. The basement membrane prevents leakage of blood so this type of vessel is often found in the brain and most of the body.
Describe briefly the structure of fenestrated vessel and where it is typically found.
Endothelial layer with fenestrations (lots of tiny wholes) which allow small molecules eg fluid and electrolytes across the membrane. It is wrapped in a basement layer. They are typically found in pituitary/kidneys/small intestine/ some endocrine glands
Describe briefly the structure of a sinusoid vessel and where it is typically found.
Both the endothelial layer and the basement membrane surrounding it have large wholes which allow larger molecules eg proteins to pass through. They are typically found where cells are made to allow the cell back into the blood stream eg bone marrow/ spleen/ liver/ lymph nodes
How is the location of specialisations different in hepatocytes to normal cells?
Specialisations are usually on the apical surface whereas in hepatocytes the specialisations are on the basal sides. Also cells usually only have one apical surface however hepatocytes have 2 apical surfaces
Where are Kupffer cells only found?
The liver
What are Kupffer cells?
Kupffer cells are specialised macrophages that form part of the sinusoidal lining.
What is the function of Kupffer cells?
Phagocytose any remaining aged/ damaged erythrocytes missed by the spleen. After splenectomy these cells take over the role of aged erythrocytes.
What is bilirubin?
Bilirubin is a brownish yellow substance found in bile. It is produced when the liver breaks down old RBC. It is then removed from the body in stool, and gives stool its normal brown colour.
What is the function of Ito cells?
Adds lipid droplets to vitamin A (vit. A is lipid soluble)
What happens to the liver in liver cirrhosis?
Hepatic stellate cells (Ito cells) lose their vitamin A storage ability and differentiate into myofibroblasts ( mix between muscle cell and cell which lays down fibre.) These cells synthesis and deposit collagen into the space of disse (perisinusoidal space) which causes liver fibrosis(excess connective tissue aka scarring)
One function of the liver is storage. Name 4 things the liver stores.
Iron, Copper, Glycogen and Vitamins A,B,K, D
One function of the liver is anabolism (production). Name
It’s worth noting the liver makes around 60% of all the body’s proteins.
Mayor plasma proteins eg Albumin (transport protein in serum)
Enzymes
Lipid Carrier proteins
Amino acid synthesis
Haemopoiesis (in the fetus)
One function of the liver is catabolism (destruction). Give 4 examples.
Drugs
Hormones eg insulin
Poisons/ toxins
Haemoglobin
Where is bile produced?
The Liver
What is the jejunum?
Part of the small intestine found between the duodenum and the ileum.
What type of response is the sympathetic nervous system responsible for?
Sympathetic Nervous system = fight or flight response eg causes muscle to contract and heart rate to increase
What type of response is the parasympathetic nervous system responsible for?
Parasympathetic = rest and digest response eg lowers heart rate and causes muscles to relax
