Lecture 16 - Endocrine 2 Flashcards
Thyroid Gland function
Regulates metabolism
Structure of thyroid gland
Follicular cells and colloid
Colloid cell function
Stores a mixture of the thyroid hormones for longterm
Thyroid Hormone Synthesis
- Begins with tyrosine
- Monoiodotyrosine (gains 1 iodine), and diiodotyrosine (2 iodines)
- Combines to form Triiodothyronine (t3)
- Tetraiodothyronine (T4)
Which form of hormone is active?
T3
Sections of the Adrenal cortex
Zona glomerulosa
Zona fasciculata
Zona reticularis
Effect of cortisol on the body
Increase blood glucose
Increase blood amino acids
Increase blood fatty acids
Epinephrine
reinforces the sympathetic nervous system to prepare the body for fight or flight
- Mobilizes carbohydrate and fat energy stores, increases blood glucose and fatty acids
CRH-ACTH-cortisol
Mobilizes energy stores and metabolic building blocks for use as needed
- increases blood glucose, amino acids and fatty acids
Glucagon
Increases blood glucose and blood fatty acids
Insulin
Decrease blood glucose and blood fatty acids
Renin-angiotensin-aldosterone
Conserve salt and water to expand plasma volume
- help sustain BP when acute loss of plasma volume occurs
Vasopressin
Cause arteriolar vasoconstriction to increase BP
Anterior Pituitary Growth Hormone
indirect action through IGF-1
- metabolizes fat sources as energy to preserve glucose for the brain directly
How is growth hormone regulated?
Through GHIH and GHRH
Insulin Structure
C peptide- connecting chain
A chain - disulfide bonds gives insulin its shape
Factors that increase blood glucose
- Glucose absorption from digestive tract
- Hepatic glucose production
Factors that decrease blood glucose
Transport of glucose into cells for energy production and storage
- Urinary excretion of glucose
What cells produce glucagon
Alpha cells of the pancreas
What cells produce insulin
Beta cells of the pancreas
What occurs with an increase in blood glucose
insulin increased, glucagon decreased
- decreased blood to normal levels
What occurs with a decrease in blood glucose
Decreased insulin, increased glucagon, increase blood glucose to normal
