MET2 Revision2 Flashcards
What are the anterior and posterior lobes of the pituitary gland AKA? [2]
Anterior pituitary: Adenohypophysis
Postierior pituitary: Neurohypophysis
Where are the cell bodies of posterior lobe and where are the axons? [2]
Cell bodies: hypothalamus
Axons: extend down posterior pit
Describe the Posterior Pituitary-neural connection and how oxytocin / ADH are released?
Which nuclei are ADH / oxytocin from/ [2]
ADH released from cell bodies in supraoptic nuclei
Oxytocin releaesd rfom paraventricular nuclei
Axons transport Oxytocin/ADH
Hormones secreted directly into capillary bed
Where do each of the following work their magic?
Adrenocorticotrophic hormone (ACTH) [1]
Thyroid-stimulating hormone (TSH)
[1]
Luteinising hormone (LH) & Follicle-stimulating hormone (FSH) [1]
Prolactin (PRL) [1]
Growth hormone (GH) [1]
Adrenocorticotrophic hormone (ACTH)
Adrenal glands
Thyroid-stimulating hormone (TSH)
Thyroid gland
Luteinising hormone (LH) & Follicle-stimulating hormone (FSH)
Reproductive organs
Prolactin (PRL)
Lactation
Growth hormone (GH)
Metabolism and growth
What would be the visual defect as a result of a pituitary adenoma?
Bitemporal hemianopia
How do you remove pituitary gland ademonas? [1]
Go into via sphenoid air sinus and remove
What are Cushing syndrome caused by? [1]
What are symptoms?
Cushing’s syndrome is a condition caused by having too much cortisol in body
Common symptoms of Cushing’s syndrome include more body fat on your chest, tummy, neck or shoulders. Your face may also be red and puffy
Which hormones are usually effected in pituitary ademona? [4]
GH, TSH, ACTH or Prolactin
What are results of overproduction of each of the following?
- Adrenocorticotrophic hormone (ACTH) [1]
- Thyroid-stimulating hormone (TSH) [1]
- Luteinising hormone (LH) & Follicle-stimulating hormone (FSH) [1]
- Prolactin (PRL) [1]
- Growth hormone (GH) [1]
- Adrenocorticotrophic hormone (ACTH): XS cortisol: Cushing’s sydnrome
- Thyroid-stimulating hormone (TSH): Hyperthyroidism, weight loss, rapid HR, tremors
- Luteinising hormone (LH) & Follicle-stimulating hormone (FSH): irregular menstrual periods, decreased interest in sex
- Prolactin (PRL): irregular menstrual periods, abnormal milk producton
- Growth hormone (GH): Gigantism in children, acromegaly in adults
Which are the glandular and neural parts of the adrenal glands?
Cortex (outer layer): glandular
Medulla (middle layer): neural part
Describe nervous supply to adrenal glands
Specialised sympathetic ganglion:
preganganglion sympatheric neurons in spinal cord run out of spinal cord and to sympathetic chain and don’t synapse
The chromaffin cells act as enlarged post-ganglionic fibers that release their neurochemicals directly into the blood stream instead of at a neuroeffector junction.
NO SYNPASE IN ADRENAL MEDULLA
NO POST GANGLION: NO POST SYNAPTIC FIBRES
The adrenal glands get their nerve supply from the coeliac ganglion, from the lesser and least splanchnic nerves
‘B’ represents the zona fasiculata, which produces and secretes corticosteroids such as cortisol.
What is the role of:
Testosterone [1]
Cortisol [1]
Aldosterone [1]
Testosterone: sexual characteristics
Cortisol: stress response
Aldosterone: regulation of sodium
Describe the blood supply to the adrenal glands? [3] & sources? [3]
The adrenal glands have a rich blood supply via three main arteries:
Superior adrenal artery – arises from the inferior phrenic artery
Middle adrenal artery – arises from the abdominal aorta.
Inferior adrenal artery – arises from the renal arteries.
Which of the following secretes cortisol?
A
B
C
D
E
Which of the following secretes cortisol?
A
B
C : zona fasciculata
D
E
Lavel A-D
A: Thyrohyoid
B: Sternothyroid
C: Omohyoid
D: Sternohyoid
Which vert. levels does the thryoid gland lie between? [1]
Which cartilage does the thymus sit on? [1]
C5-T1
Sits on Cricoid cartilage
Label the nerve supply in A-D
A: Vagus nerve
B: Superior laryngeal nerve
C: Internal branch, superior laryngeal nerve
D: External branch, superior laryngeal nerve
Which two structures are closely related in the thryoid area? [2]
Superior thryoid artery is close to the external laryngeal nerve at its origin: have to ligate superior thyroid artery near superior pole of thyroid
Which structures are found in the carotid sheath? [4]
carotid artery, jugular vein, vagus nerve, and sympathetic plexus.
Why does the pancreas have two blood supplies? [2]
Gets blood from CT and SMA as develops from two parts that fuse together
How can triglycerides be used to produce ATP?
Triglycerides broken down by lipase in fatty acids and glycerol
Fatty acids can make acetyl coA via beta oxidation and therefore ATP
How does body create fuel source at:
a) post absorb. state?
b) when glucose stores are used up?
c) continued fasting
d) further fasting
Post absorbative state:
- Muscle and adipose tissue reduce their glucose utilisation
If glucose stores are used up (24hr store) moves:
- triglyceride stores: fatty acids are used to make ATP via beta oxidation in cartinine shuffle.
- glucose made at the liver via gluconeogensis (using lactate, amino acids or glycerol) to continue a glucose supply
If continued fasting: ketogenesis occurs:
- Brain and RBC use glucose from hepatic and renal gluconeogenesis
- Other tissues use keto molecules as an additional fuel source
Prolonged fasting:
- Brain reduces glucose use; uses some ketone bodies (but glucose is still required)
- RBC use glucose from renal and hepatic GNG
What is refeeding syndrome?
Which deficiences are like to get? [3]
What can it lead to? [2]
Upon refeeding, synthesis of glycogen, triglycerides, proteins
This requires intracellular ions, however these have been depleted throughout starvation. Get transport of ions (particularly K) intracellularly.
Causes a depletion of serum ion levels: can get Hypophosphataemia, hypokalamia, thiamine deficiencies
Leading to congestive heart failure and peripheral oedema
During the fasting state which processes are occurring in
a) muscle
b) liver
c) adipose
Muscle
* Glycogen is broken down (GLYCOGENOLYSIS) to provide ATP
Liver:
* GLYCOGENOLYSIS in liver releases glucose into bloodstream (reserve depleted in 24 h)
* GLYCOLYSIS is inhibited in the liver.
* Liver synthesises new glucose (GLUCONEOGENESIS) from amino acids, lactate, glycerol
Adipose tissue:
* Triglycerides are broken down in adipose tissues (LIPOLYSIS) – to provide glycerol (used in gluconeogenesis) and fatty acids
Explain how insulin works to allow glucose into cell in healthy cells? [5]
- Insulin binds to insulin receptor
- Autophosphorylation of the receptor occurs
- IRS is phosphorylated by the receptor on Tyrosine residues
- Phosphorylated IRS can now bind to PI3K which moves from the cytoplasm
- Causes PIP2 to PIP3
- Causes activation of AKT pathwayand GLUT 4 to move to membrane
GLUT4 transporters are now inserted into the membrane
Glucose can cross the membrane & it can be stored
How can insulin resistance occur? [6]
Decrease in the number of insulin receptor
Decrease in the catalytic activity of the receptor
Increased activity of Tyrosine phosphatases
Decreased levels and function of GLUT4
Increased Ser/Thr phosphorylation of the receptor or of IRS
Decreased PI3K/Akt activity
What physiological responses occur in response to insuline resistance in obesity or pregnancy? [3]
What does this mean physiologically? [1]
New β cells can be generated in response to insulin resistance associated with obesity or pregnancy
Islets increase in both size and number due to Beta cell increase in size and number
Increased β function
THEREFORE Glucose tolerance can be maintained by increased insulin secretion
In which situitations may hypoglycaemia occur in diabetic ptx? [4]
Medications:
* Common complication when using insulin or other insulin secretagogues
* Skipped/postponed meals when taking medications
* Increasing physical activity without adjusting food ingestion/medications
Alcohol excess:
Inhibition of gluconeogenesis
What is an important symptom of mild hypoglycaemia?
Why is recurrent hypoglycaemia dangerous?
Mild hypoglycaemia:
* can lead to several hours of mental and physical recovery and can impact work performance
* can contribute to worry and fear, potentially leading to poor glycaemic control
Recurrent hypoglycaemia can lead to:
* suppression of the normal physiological counter-regulatory response
* development of impaired awareness of hypoglycaemia
Which pathways are activated during hyperglycaemia that can cause damage [3]
- Oxidative stress: get increased expression and activity of vascular NADH oxidase. Leads to ROS accumulation
- Increase in polyol pathway: increased AGE production
- Converted to PKC pathway: creates more ROS
How can oxidative stress induce cellular damage? [3]
- Oxidative damage to macromolecules
- Impairment of NO signalling pathway
- Activation of pro-inflammatory signalling cascades
What are AGE products?
Advanced Glycation End products (AGEs) are proteins or lipids that become glycated
Causes:
Structural modificaiton of proteins: basement membrane thickness, reduced vascular elasticity etc
Interaction with AGE receptors: activation of signalling, gene expression, secretion of pro-inflammatory molecules, increased production of free radicals etc)
What is the name for where the main and accessory pancreatic ducts drain into the duodenum? [2 - two names]
What is the structure that surrounds ^? [1]
Ampulla of vater / pancreatoduodenal ampula
Sphincter of Oddi
The ampulla of vater is formed of formation of which two ducts? [2]
Common bile duct [1]
Main pancreatic duct [1]
Which structures make the porta hepatis? [3]
Pancreatic arterial supply?
pancreatic branches of the splenic artery
superior and inferior pancreaticoduodenal arteries which are branches of the gastroduodenal (from coeliac trunk) and superior mesenteric arteries, respectively.
Label A-C
A: Coronary ligament
B: Falciform ligament
C: Ligamentum teres
What are the lobes of the liver? [4]
Draw them x
Right lobe
Left lobe
Caudate lobe
Quadrate lobe
What is the difference between cystic duct and bile duct?
The cystic duct connects the gallbladder (a small organ that stores bile) to the common bile duct
The common bile duct: passes through the pancreas before it empties into the first part of the small intestine (duodenum).
Which embryological structure is the ligamentum teres a remnant of? [1]
Umbilical vein
Label A & B [2]
A: Isthmus
B: Parathyroid glands
Describe the arterial supply to the thyroid [2]
And their sources [2]
- The superior thyroid artery (STA) arising from the external carotid artery (ECA)
- The inferior thyroid artery (ITA) branching from the thyrocervical trunk
Describe venous drainage & route of the thyroid [5]
The thyroid gland is drained via the superior, middle, and inferior thyroid veins: form a venous plexus around the thyroid gland. [3]
Superior and middle veins drain into the internal jugular vein [1]
Inferior vein: empties into the brachiocephalic vein [1]
What supplies sympathetic [1] & parasympathetic [1] nervous supply to thryoid?
SNS: Cervical ganglion
PNS: Recurrent LN
Describe the blood supply to the adrenal glands? [3] & sources? [3]
The adrenal glands have a rich blood supply via three main arteries:
Superior adrenal artery – arises from the inferior phrenic artery
Middle adrenal artery – arises from the abdominal aorta.
Inferior adrenal artery – arises from the renal arteries.
Describe adrenal venous drainage [2]
Right and left adrenal veins drain the glands.
The right adrenal vein drains into the inferior vena cava
The left adrenal vein drains into the left renal vein.
An increase in which hormone causings this syndrome? [1]
Cortisol (Cushings syndrome)
Label 14, 19, 20, 21, 22 & 23
14 Superior suprarenal artery
19 Right inferior phrenic artery
20 Left inferior phrenic artery
21 Middle suprarenal artery
22 Inferior suprarenal artery
Label 5-10
5 Splenic artery
6 Upper pole of kidney
7 Anterior branch of renal artery
8 Interlobular arteries
9 Left renal artery
10 Lower pole of kidney
Label 1-4
1 Celiac trunk
2 Superior mesenteric artery
3 Middle colic artery
4 Abdominal aorta (with catheter)
Label A-E
A: Internal branch of superior
laryngeal nerve
B: Inferior thyroid artery
C: Superior laryngeal nerve
D: Glossopharyngeal nerve
E: Inferior laryngeal branch of recurrent
laryngeal nerve
Label 40-45
40 Internal carotid artery
41 External carotid artery
42 Superior laryngeal artery
43 Superior thyroid artery
44 Common carotid artery
45 Thyroid ansa of sympathetic
trunk and inferior thyroid artery
