W10 - The Endocrine System Flashcards
What manufactures specific hormones?
Specialised epithelial secretory cells
What are the different ways in which hormones can communicate?
Endocrine
Autocrine
Paracrine
Juxtacrine
What do hormones ultimately do?
Reg cell function
Metabolism
Homeostasis via their effects on enzyme
What are the 2 main categories of hormones?
Steroid
Non-steroid
What are the lipid soluble steroid hormone synthesised from?
Cholesterol
How do the steroid hormones circulate in the blood?
Bound to a carrier protein i.e albumin
What are the steroid hormones bound to binding proteins called?
Inactive
How do steroid hormones transport/function?
Diff into cell
Specific receptor located in cytoplasm or nucleus,
Hormone-receptor complex activates gene expression
Protein synthesis is induced
Are non-steroid hormones water or fat soluble?
Water
Can non-steroid hormones diffuse across cell membranes?
NO
Give examples of steroid hormones
Glucocorticoids
Aldosterone
Sex hormones
What happens in a -ive feedback loop?
Stimulus activates endocrine gland.
Gland secretes hormone
Target cells respond to hormone - reducing original stimulus
Switches off further hormone prod by gland
What is the pituitary gland often termed?
Master regulator
How is the pituitary gland divided?
Anterior lobe
Posterior lobe
What are the lobes of the pituitary gland under direct control from?
Hypothalamic hormones
Posterior lobe of the pituitary gland stores hormones made by what and release into where?
Made by hypothalamic neurones
Releases into circulation
Where does the anterior lobe of the pituitary gland receive hormones via?
Via vessels
= Stimulating further hormone release by pituitary.
What 2 hormones does the posterior pituitary lobe secrete?
ADH
Oxytocin
What is oxytocin responsible for?
Uterus contraction
Milk ejection during lactation
What does the pineal gland produce?
Melatonin (derivative of serotonin)
- Released in rhythmic fashion
What is the pineal gland suppressed by?
Light
= Most active at night.
What does the pineal gland do?
Modulates sleep patterns in circadian rhythms.
What 2 hormones does the thyroid gland secrete?
Thryoxine
Triiodthyronine
What is the thyroid gland involved in?
Tissue development
Macronutrient metabolism
What does the parathyroid gland produce?
Parathyroid hormone (PTH)
What are the dual functions of the pancreas?
Exocrine function
Endocrine function
What are the endocrine parts of the pancreas called?
Islets of Langerhans
What are the 4 types of cells in the pancreas?
Alpha cells
Beta cells
Delta cells
F cells
What is the primary role of the endocrine pancreas?
Reg blood glucose levels
What cells in the pancreas secrete glucagon?
Alpha cells
What cells in the pancreas secrete insulin?
Beta cells
What does each adrenal gland consist of?
Outer adrenal cortex
Inner adrenal medulla
What are the 3 main endocrine dysfunctions?
Abnormal hormone receptor function/levels
Altered intracellular response to hormone-receptor complex
Hyper/hypo secretion of hormones by glands
What can stimulate GLUT4 recruitment to the cell surface?
Insulin + exercise
What does diabetes mellitus type 1 result from?
Bodys failure to produce insulin
Onset typically in early childhood
What does diabetes mellitus type 2 result from?
Insulin resistance - cells fail to use insulin properly
Onset typically in adulthood
Type 1 Diabetes Mellitus (T1DM)
What % of what must be destroyed for hyperglycaemia to occur?
80-90% of beta cells
How is glucose supply during exercise maintained?
Mobilisation of glucose from liver glycogen stores
Mobilisation of FFA from adipose tissue
Gluconeogenesis from aa, LA + glycerol.
