ENDOCRINE SYSTEM Session 9 Flashcards
What does the adrenocorticotropic hormone stimulate ?
- Adrenal cortex to produce cortisol
What are examples of gonadotropic hormones and what do they stimulate ?
- Follicle stimulating hormone (FSH) and luteinizing hormone (LH) stimulate the gonads to produce gametes and sex hormones
What does the thyroid stimulating hormone do ?
- Stimulates the thyroid to make thyroid hormones.
What does prolactin do ?
- Causes mammary glands to produce milk after childbirth
What does growth hormone do ?
- Somatoropic hormone , promotes skeletal and muscular growth
What is Pituitary dwarfism , gigantism and acromegaly ?
- Pituitary dwarfism : too little GH in children
- Gigantism : too much GH in children
- Acromegaly : too much GH in adults
What does the thyroid gland regulate ?
- regulates the metabolic rate of the body , plays a role in calcium homeostasis
What is the thyroid gland composed of ?
- Composed of follicles with triiodothyronine (T3) and thyroxine which contains 4
how does calcitonin get controlled ?
- It is secrete by the parafollicular of thyroid gland
When are parathyroid hormones released and what does it promote ?
- It is released when there is low blood calcium levels
- Promotes the activity of osteoclasts , which remove calcium from bones (increasing blood calcium levels)
- Activates vitamin D which then promotes calcium reabsorption by the kidneys and stimulate absorption of calcium ions from food
What does the adrenal gland consist of ?
- An inner portion called the adrenal medulla
- An outer portion called the adrenal cortex
How does the hypothalamus signal the adrenal medulla to release its hormones ?
- It sends nervous signals that travel through preganglionic sympathetic nerve fibres to the adrenal medulla to stimulate it to secrete its hormones
What are examples of hormones that the adrenal medulla releases ?
- Epinephrine
- Norepinephrine
What are the three regions that the adrenal cortex is divided into ?
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
What are examples of major types of hormones that are produced ebb the adrenal cortex ?
- Glucocorticoids
- Mineralocorticoids
Where are Glucocorticoids produced in the adrenal cortex and what do they regulate and how is the secretion controlled ?
- produced in both the zone fasciculate and zone reticularis
- secretion is controlled by ACTH
- Regulates carbohydrates , protein and fat metabolism
In what two ways do glucocorticoids raise the blood glucose level ?
- Promotes the breakdown of muscle proteins in amino acids which are taken up by the liver
- Promotes the metabolism of fatty acids rather than carbohydrates ; this spares glucose
Where are mineralocorticoids produced in the adrenal cortex and what do they regulate ?
- Produced by the zone glomerulosa of the adrenal cortex
- regulates ion balance in the body
Where are sex steroids produced in the adrenal cortex ?
- in the Zone fasciculata and the zone reticularis
What is another name of sex steroids ?
-Gonadocorticoids
What does the exocrine and endocrine sections of the Pancreas secrete ?
- Exocrine tissue secretes digestive enzymes
- Endocrine tissue is located within pancreatic islets :
A cells = secrete glucagon
B cells = secrete insulin
D cells = secrete somatostatin
When are Glucagon A cells secreted and what does it stimulate ?-
- Secreted when blood glucose levels are low
- Stimulates the liver to break down glycogen to glucose
When are Insulin B cells secreted and what does it stimulate ?
- Secreted when blood glucose levels are high
- Stimulates the uptake of glucose by cells , especially liver cells muscle cells and adipose cells
What is diabetes mellitus and how does it effect the body ?
- its when there is an excess of glucose in the blood
- but when blood glucose levels rise , glucose with water is excreted in the urine
What are the two types of diabetes and explain each of them ?
- Type 1 : sometimes called juvenile diabetes or insulin dependent diabetes
- Type 2 : also known as adult onset diabetes or non insulin dependent diabetes mellitus ( insulin resistant )
How does type 1 diabetes occur and what does it cause ?
- its when pancreas does not produce enough insulin
- Caused by exposure to an environmental agent , most likely a virus
What must you do daily if you have type 1 diabetes?
- Inject insulin daily
What are the blood sugar level that an individual with type 1diabetes could swing in and what are the treatments for each of them?
- hypoglycaemia ( low blood glucose ) : ingesting sugar
- Hyperglycemia ( high blood glucose ) : treatment is insulin
