Liver Flashcards
What is a portal system?
Two capillary systems in series
What are the two portal systems in humans?
Hepatic portal system
Hypothalamo-hypophyseal portal system
Where is the hypothalamo-hypophyseal portal system?
blood supply to the anterior pituitary
Where does the hepatic portal system pass through?
stomach and intestines and then the liver
Whats travelling in the portal vein?
Water, vitamins, electrolytes, carbohydrates, proteins, interstinal hormones, toxins
What occurs in the liver only?
complete urea cycle (krebs)
What are toxins?
chemical, bacteria, viruses, protozoa, nematodes, chested, trematodes
What does not travel in the portal vein?
Lipids- travel in lymphatics as chylomicrons
Fat soluble vitamins
What are lacteals?
specialised lymphatic vessels on the surface of the call intestine
What are the functions of the liver?
Metabolism
Storage- carbs, fat, protein, iron, vitamins, glycogen
Detoxification
Bile production
What is produced in the liver?
Albumin, glycogen, coagulation factors, haematopoiesis
What is broken down in the liver?
Drugs, hormones, haemoglobin, poison, old blood cells if splenectomy
What is critical to the filtering function of the kidney?
Macrophages (kuppfer cells)
What is the exocrine function of the liver?
Bile secretion
What is the endocrine function of the liver?
produces hormones e.g. angiotensinogen
modifies vitamin d and thyroxine to active forms
Breaks down insulin, glucagon, oestrogen and progesterone
What is a hepatocte?
80% of liver cells, regenerates, lots of mitochondria, peroxisomes, free ribosomes, lots of RER, golgi and SER, glycogen deposits
What is a sinusoid?
Irregular tubular space for the passage of blood
Where do the lymphatics arise and drain in the liver?
Arise- periportal space of mall
drain- liver hilium
What is a bile canaliculus?
Hepatocytes create bile and put them in the bile canaliculus to the bile duct
What are kuppfer cells?
macrophages that form part of the sinusoid
recycle old blood cells and ingest pathogens
What are stellate cells?
Cytoplasmic vaculoles which contain vitamin A
In liver cirrhosis they stop storing liver and differentiate into myofibroblasts which synthesise collagen which constricts the central vein causing portal hypertension
