Endocrine System Flashcards
What is an exocrine gland?
A gland which secretes into DUCTS, which empty into body cavities or body surfaces
What is an endocrine gland?
A gland which secretes products directly into interstitial fluid (blood) - DUCTLESS
What type of gland is the panceas?
They have both exocrine and endocrine functions
What type of gland is Pituitary gland?
Endocrine
What type of gland are salivary glands?
Exocrine
What type of gland is the thyroid gland?
Endocrine
What type of gland is the pineal gland?
Endocrine
What type ofg land are sweat glands?
Exocrine
What type of gland are adrenal glands?
Endocrine
What is the definition of a hormone?
Chemical substances secreted by cells into extracellular fluid, in order to alter cell activity
What is an endocrine/circulating hormone?
Hormones that travel in blood, and act on distant target cells
What is a local hormone?
Hormones that act locally, without entering the bloodstream
What is a paracrine?
A local hormone that acts on a neighbouring cell
What is an autocrine?
A local hormone that act on the same cell that secreted them
What type of feedback system are blood hormone levels controlled by?
Negative
Hormones are synthesised and released from endocrine in response to the following stimuli:
1.
2.
3.
- Humoral
- Neural
- Hormonal
How is the pancreas connected to the duodenum?
Via the pancreatic duct and the accessory duct
What duct does the pancreatic duct fuse with going into the duodenum?
Common bile duct
True or false: if the sphincter of the main pancreatic duct is closed, no pancreatic juices will be able to enter the duodenum.
False - pancreatic juices will enter (at a smaller rate) through the accessory duct
What is the hepatopancreatic apulla?
The point of dilation where the pancreatic duct and common bile duct join together
What is the hepatopancreatic spchinter?
The sphincter between the duodenum and the pancreatic duct
What are pancreatic islets / islets of langerhans?
Irregular clusters of endocrine cells scattered throughout the tissue of the pancreas which secrete:
Glucogen from alpha cells
Insulin from beta cells
What do alpha endocrine cells secrete?
Glucagon
What do beta endocrine cells secrete?
Insulin
Where are alpha and beta cells located?
In the Pancreatic Islets / Islets of Langerhans
What is the major target organ of Glucagon?
The Liver
What functions does Glucagon promote in the liver?
Glycogenolysis
Gluconeogenesis
The release of glucose from the liver
What is Glycogenolysis?
The breaking down of glycogen into glucose
What is Gluconeogenesis?
The creation of glucose from fats and proteins
True or false: Glucagon has a negative effect on blood glucose levels.
False - glucagon increased blood glucose levels
What is the function of insulin?
- Enhances the transport of glucose into body cells
- Counters metabolic activity which would increase blood glucose levels
True or false: Insulin secretion leads to decreased blood glucose levels
True
What causes type 1 diabetes?
Hypoactivity or Hyposecretion of insulin
What causes type 2 diabetes?
Defective insulin receptors
(AKA insulin independent diabetes)
What causes gestational diabetes?
Pregnancy hormones making the body insulin-resistant
What are the three signs of diabetes?
- Polyuria (excessive urination)
- Polydipsia (excessive thirst)
- Polyphagia (excessive hunger)
What causes Diabetes insipidus?
Hyposecretion of Antidiuretic Hormone (ADH) due to hypothalumus or posterior pituitary gland damage
