week 9- endocrine

Question 1

endocrine system

Answer 1

Glands scattered throughout body that produce & secrete hormones regulating cellular/organ activity.

Question 2

pituitary gland- and what can go wrong?

Answer 2

Anterior pituitary gland: regulates growth, maturation, & reproduction
Posterior pituitary gland: secretes oxytocin & ADH
Most common dysfunction caused by tumour.
- may cause secretion failure (partial or total secretion failure)
-this can cause metabolic dysfunction, sexual immaturity, & growth retardation
-also Pituitary gland is highly vascular so extremely vulnerable to ischaemia & infarction from tumor

Question 3

thyroid hormone- and what can go wrong?

Answer 3

• Secretes two thyroid hormones in response to hypothalamic-pituitary secretion of thyroid-stimulating hormone
• Goitre and Hyperthyroidism

Question 4

Goitre

Answer 4

Enlargement of thyroid gland

Caused by hypo & hyperthyroidism conditions

Question 5

Hyperthyroidism

Answer 5

-Metabolic imbalance due to increased secretion of T4, T3
-graves is most common form- gravs is an increase in T4 production, manifesting as:
Hyper-metabolism
Toxic goitre
Exophthalmos – eye muscles swell, pushing globe outwards

Question 6

Thyroid Storm (Thyrotoxic Crisis)

Answer 6

is an extreme version of graves disease
Life threatening because of resultant:
Hyperthermia: 41°C or higher 
Tachycardia
Heart failure
Delirium or coma

Question 7

Hypothyroidism

Answer 7

Hypothalamic, pituitary, or thyroid insufficiency/resistance to thyroid hormone
Most common disorder of thyroid; more prevalent in women
-chronic includes myxedema and cretinism

Question 8

Hypothyroidism- Myxedema:

Answer 8

non-pitting oedema seen in facial puffiness & thick tongue

Question 9

adrenal cortex

Answer 9

-Small bilateral structures, lie on apex of each kidney
-Medulla secretes epinephrine & norepinephrine
-Cortex responsible for secreting 3 types of hormones:
Glucocorticoids, including cortisol
Mineralcorticoids, including aldosterone
Adrenal androgens
-issues include Cushing’s Syndrome, Addison’s Disease

Question 10

Cushing’s Syndrome

Answer 10

Excessive glucocorticoids (E.g. hydrocortisone or cortisol)
Due to tumour or large amounts of glucocorticoids administered
-gives moon face and makes skin weak

Question 11

Addison’s Disease

Answer 11

Deficiency of adrenocortical secretions
causes-Decreased BGL
Poor stress response
Weight loss, fatigue
Anorexia, nausea, diarrhoea

Question 12

regulation of BGL

Answer 12

insulin-secreted by beta cells (islet of langerhan)
-direct effect lowering BGL
-Promotes glucose uptake by target cells & glucose storage
-Prevents fat & glycogen breakdown
glucagon-secreted by alpha cells
-maintains BGL between meals/fasting
-Exerts main action in liver
-Increases plasma glucose via glycogenolysis & gluconeogenesis

Question 13

type 1 diabetes

Answer 13

-complete destruction of the pancreatic beta cells.
-hyperglycaemia (in the blood) due to lack of insulin, lack of insulin effect, or both.
Typically, genetically susceptible to type 1 diabetes undergoing a triggering event.
-may be in the form of a bad infection, or huge physiological stress causing auto-antibodies to be produced, which destroy beta cells, resulting in lack of insulin secretion.

Question 14

diabetic ketoacidosis

Answer 14

-DKA occurs in type 1 diabetics where there is no glucose available to the cells, as there is no release of insulin.
-insulin stops breakdown of fats (lipolysis) for energy, and instead uses glucose as fuel instead.
-however due to no insulin, glucose remains in the blood stream, causing hyperglycaemia and body doesnt have energy source.
So uses breakdown of fats (lipolysis) instead, these fats must be converted into ketones to be used for energy, moving the body into a state of ketosis.
Ketones have a fruity smell about them, patients in DKA will smell fruity.
- state of ketosis, acid is being produced, resulting in metabolic acidosis. In order to combat this, bicarbonate is used to buffer the acid: To remove the carbon dioxide, the body increases the respirations, resulting in ‘Kussmaul’ respirations – of increased rate and depth.

Question 15

type 2 diabetes

Answer 15

• Type 2 diabetes- most common, results in hyperglycaemia due to insulin resistance.
• However, there is NO autoimmune-mediated destruction of the beta cells.
• caused by impaired insulin production, inappropriate liver glucose production, and/or peripheral insulin receptor insensitivity.

Question 16

Gestational diabetes

Answer 16

Gestational diabetes describes glucose intolerance during pregnancy in women with no history of diabetes. It is thought that the placental hormones counteract insulin, resulting in insulin resistance. It is associated with larger babies (>4kg). Normally, this disappears when the pregnancy is over, but these women are now at higher risk of type 2 diabetes in later life.

Question 17

HHS or hyperglycaemia non-ketoacidosis (HONK)

Answer 17

HHS or hyperglycaemia non-ketoacidosis (HONK) occurs in type 2 diabetics.

• Impaired insulin production, inappropriate liver glucose production, and/or peripheral insulin receptor insensitivity results in lesser entry of glucose to the cells, meaning it remains in the vascular (blood) system. Because type 2 diabetes is a slower onset disease, these patients are used to regularly having periods of hyperglycaemia. As such, their BGL may be incredibly high (>30mmol/L).
• Glucose has a large effect on water molecules, causing it to be pulled from any cells it can (generic tissues and the brain). Because of this hyperosmolarity, HHS patients become acutely dehydrated. When water is pulled from the brain, the patient may also begin to suffer neurological symptoms (hemiparesis, seizures, coma).

Question 18

clinical manisfestations of diabetes

Answer 18

Polyphagia: excessive hunger
Polydipsia: excessive thirst
Polyuria: excessive urination

Abdominal pain: typical first time child presentation
Nausea & vomiting
Weight loss
Lethargy
Blurred vision
Frequent infections: slow healing sores, thrush or urinary tract infections