Block 15 Flashcards
(32 cards)
What are the main causes of cirrhosis of the liver?
Steatosis –> hepatitis –> cirrhosis
Causes of steatosis = alcoholic fatty liver disease + non-alcoholic fatty liver disease
Causes of hepatitis = viral (A, B, C, EBV, HSV, VZV), autoimmune (3 main diseases), metabolic (Wilson’s, haemochromotosis)
What are the main autoimmune diseases of the liver that can cause cirrhosis?
Autoimmune hepatitis
Primary sclerosis cholangitis (autoimmune disease of the bile ducts both intra-hepatic and post-hepatic)
Primary biliary sclerosis (autoimmune disease of the small bile canuliculi)
What are the two main features of liver cirrhosis?
Fibrosis (usually encircling the lobule)
Nodules (formed from hyperplasia of hepatocytes within the boundaries of fibrosing strictures)
What is a keiser-fletcher ring?
A ‘golden halo’ found within the iris of patients with Wilson’s disease, caused by large deposits of copper
What are the major proteins found within the blood?
Albumin
Globulin
Fibrinogen
What are the major tests that are part of the liver function panel?
Bilirubin Albumin Total protein Aspartine aminotransferase Alanine aminotransferase Gamma-glutamyltransferase Alkaline phosphatase
What do raised AST or ALT mean?
AST = non liver specific and found in cardiac and skeletal muscle. ALT = is liver specific
The ratio of ALT to AST can provide insight but complex.
A very high level of these enzymes suggest: drug induced hepatitis, viral hepatitis, ischaemia or autoimmune hepatitis.
Why is albumin not useful as an indicator for acute liver diseases?
Has a half life of ~ 20 days
What does a raised GGT suggest?
Related to the bile ducts - cholecystitis
What does raised ALP suggest?
Comes from the cells lining the bile ducts. Raised with GGT in cholecystitis and other inflammatory diseases of the gall bladder.
What is the relative incidence and death rate of bowel cancer?
4th most common cancer (after breast, prostate and lung)
2nd most common cause of cancer death (after lung)
What are the causes of acute pancreatitis?
Idiopathic Gall stones Ethanol Trauma Steroids Mumps Autoimmune Scorpion bites Hyperlipidaemia ERCP Drugs
What are the 3 main results of septic shock - caused by microbial constituents or inflammatory mediators?
Hyper-coagulability
Vasodilation
Increased vascular permeability
What hormones are produced from the anterior pituitary?
Thyroid stimulating hormone Adrenocorticotropic hormone Leutinizing hormone Follicle stimulating hormone Prolactin Growth hormone
What hormones are secreted from the posterior pituitary?
Oxytocin
Anti-diuretic hormone
What is the action of thyroid stimulating hormone?
What is its control?
To promote release of T3 and T4 from the thyroid gland
Increases iodine uptake by the thyroid gland
Controlled by thyrotropin releasing hormone from the hypothalamus. Secretion of TRH is controlled by stress/cold by the CNS.
Inhibited by T3 and T4 levels in the blood
What is the action and control of adrenocorticotropic hormone?
Acts to release cortisol from the adrenal cortex.
(Celaved from melanocytic hormone and can cause skin pigmentation).
Controlled by CRH from the hypothalamus
Secretion has a diurnal rhythm
CRH is inhibited by negative feedback from blood glucocorticoids.
What is the action of LH and FSH?
How are they controlled?
Released by the anterior pituitary in response to GnRH from the hypothalamus. GnRH production is regulated by levels of LH and FSH in the blood. However, in females, oestrogen levels cause switch to +ve feedback and sudden rise in LH/FSH to cause ovulation once a month.
Female:
LH = stimulation of ovulation, supports the theca cells to produce testosterone, helps support corpus luteum for first 2 weeks before implantation.
FSH = stimulates granulose cells to produce oestrogen from testosterone.
Male:
LH = acts on the interstitial cells of leydig in the testes to produce testosterone
FSH = acts on the sertoli cells to promote the stimulation of sperm cells.
What is the action of prolactin and how is it controlled?
Acts on the glandular tissue (lactocytes) of the breast to stimulate milk production.
Also released during pregnancy to help development of the acinar structure of the brest
Stimulated by nervous impulses from suckling at the nipple.
What is the action of growth hormone and how is it control eld?
Acts on the long bones and soft tissue to cause growth via the release of insulin like growth factors (IGFs).
Essential for growth but growth only occurs if both growth hormone and sufficient nutrients are available.
Insulin like action to promote metabolism and uptake/storage of proteins and fats.
Released from the anterior pituitary in response to GHRH from the hypothalamus. GHRH stimulated by stress and exercise. Particularly released after just after birth and during puberty.
What are the two hormones released from the posterior pituitary?
Oxytocin
ADH
What is the function of oxytocin and how is it controlled?
Acts on the uterine myometrium to cause contraction in childbirth
Acts on the myoepithelial cells of the breast to cause ejection of milk.
Stimulated by nervous impulses from both vaginal stretch and nipple suckling.
What is the function of ADH and how is it controlled?
Acts on the distal convoluted tubule and collecting ducts of the nephron to increase water reabsorption by action on aquaporin 2.
Controlled by blood osmotic pressure via osmoreceptors in the hypothalamus.
What are the possible consequences of a pituitary adenoma?
Increased growth hormone release
Increased ACTH release
Increased LH/FSH release
Increased TSH release
