7) Exocrine Glands Flashcards
Name 2 exocrine glands
Liver
Salivary glands
What do parotid glands secrete?
serous secretions
mucus secretions
Where is the parotid gland located?
Next to the ear
Where is the parotid gland in relation to different surfaces?
On the mastoid surface
2cm below the angle of mandible
On the head of the mandible
In the middle of the masseter muscle
Which glands produce saliva?
Parotid gland
Submandibular gland
Sublingual gland
Where are the submandibular glands located?
Under the mandible
What is the structure of the submandibular gland?
Split into 2 parts:
Superficial surface - muscus
Internal surface - serous
Which nervous system controls serous secretion?
parasympathetic
Which nervous systerm controls mucous secretion?
sympathetic
Which nervous systerm controls mucous secretion?
sympathetic
Name the 2 bloody supplies to the liver
hepatic portal vein
hepatic artery
What is the structure of the hepatic portal vein blood supply?
capillaries in stomach and intestine, hepatic portal vein, sinusoids in liver
How does blood travel to the liver from the hepatic artery blood supply?
aorta, hepatic artery, liver
OR
aorta, splenic artery, spleen, hepatic vein, liver
What are the 3 types of vessels in the body?
Continuous
Fenesrated
Sinusoid
Where are continuous vessles found in the body?
Brain - prevents haematoma
Where are fenestrated vessels found in the body?
Small intestine, kidney - allow small molecules to quickly pass through
Where are sinusoid vessels found in the body?
Spleen - large molecules AND cells can get through
What is the structure of a sinusoid vessel?
Endothelial layer and basment membrane both have large holes in them
Why does the liver appear red in H&E staining?
Eosin stains proteins and the liver lobule makes lots of proteins
What are the cells of the liver called?
Hepatocytes
What is the shape of a liver lobule?
Hexagonal, each point has the portal triad (bile duct, portal vein and hepatic artery). Hepatocytes have a sinusoidal surface between them that connects to the central vein
Where are Kupffer cells located?
Within the sinsoid of the hepatocytes and can move into the Spcae of Disse
What is the role of Kupffer cells?
Acts as a specialised macrophage. Traps and phagocytoses any damaged or aged erythrocytes mised by the spleen
What is the Space of Disse?
The serum like space between the hepatocytes and the sinusoid which contains stellate cells and dendritic cells
What is the role of stellate cells?
To pick up lipid in the form of vitamin A, absorb the vitamin A and insert itself between hepatocytes to become Ito cells
What is the assumed job of dendritic cells?
To pick up bacteria or fungi and present it to B cells and T cells
Where are pit cells located?
In the sinusoid attached to endothelial cells
What is the role of pit cells?
To detect cancer cells in the sinusoid and kill them
How can you identify liver damage?
Bilirubin processed by the liver will appear yellow
What is liver cirrhosis?
When stellite cells lose their ability to store vitamin A and differentiate into myofibroblasts
What is the function of the liver?
Storage:
iron, Vitamin A, B12, D K, Copper, Glycogen
Anabolism (production):
proteins
enzymes
Catabolism (destruction): hormones haemaglobin RBCs toxins
other functions:
exocrine - bile production
endocrine - hormones/growth factors
What is autocrine signalling?
Signal is released by hepatocytes and acts on its own receptors
What is paracrine signalling?
Acts on adjacent hepatocytes causing them to proliferate
What is intracrine signalling?
hormones produced or stored in the cell have an automatic effect on gene synthesis
What is endocrine signalling?
Hormone secretion into the blood via an endocrine gland
What is consitutive secretion?
Scretion that continuously occurs regardless of external factors
