Ch 13: Endocrine Flashcards
Endocrine system functions
-Growth and repair of tissues
-Balance of energy
-Response to stress
-Maintenance of pH levels
-Reproduction
Steroid hormones
-made from cholesterol
-Estrogen and testosterone
-Aldosterone
Nonsteroid hormones
-Protein-based (Made from amino acids)
-Insulin
-Antidiuretic hormone
-Epinephrine and norepinephrine
Connecter of hypothalamus and pituitary gland
Infundibulum
Adenohypophysis
-Anterior pituitary
-Hypothalamus secretes hormones that cause it to either secrete or stop secreting a hormone
-Composed of glandular tissue
Neurohypophysis
-Posterior pituitary
-Hypothalamus produces the hormones that are stored and released here
-Composed of neural tissue
Hormones made by the hypothalamus
-Oxytocin
-Antidiuretic hormone
-Stored in posterior pituitary (neurohypophysis)
Thyroid stimulating hormone (TSH)
-Stimulates the thyroid to secrete it’s hormones
-Anterior pituitary
Prolactin
Stimulates milk production
-Anterior pituitary
Adrenocorticotropic hormone (ACTH)
Stimulates the adrenal cortex to secrete corticosteroids
Growth hormone or somatotropin (GH)
Promotes proteins synthesis, lipid and carbohydrate metabolism, bone and skeleton muscle growth
-Anterior pituitary
Luteinizing hormone (LH)
-Stimulates ovulation and oestrogen and progesterone synthesis in females
-Secretion of testosterone by males
-Anterior pituitary
Follicle stimulating hormone (FSH)
Stimulates the production of eggs in females and sperm in males
Oxytocin
Stimulates contraction of the uterus during childbirth and triggers the release of breast milk
Antidiuretic hormone or vasopressin
Acts on the kidneys to reduce urine volume and prevent dehydration
Pineal gland
-Tiny gland in the centre of the brain
-Produces melatonin
-Melatonin triggers sleepiness
-Melatonin may also be part of the timing of puberty
Thymus produces these two hormones
-Thymosin
-Thymopoietin
-Develops the immune system
Thyroid hormones
Triiodothyronine & thyroxine
-Increase the rate of metabolism
Calcitonin
-Triggers the deposition of calcium in bone in response to rising blood calcium levels
Parathyroid hormone
Causes calcium to be released into the bloodstream
What happens when there is an excess of calcium ions in the blood
Thyroid releases calcitonin
-Calcitonin causes calcium ions to move from the blood to bone, lowering blood calcium levels
What happens when there’s not enough calcium in blood
Parathyroid releases PTH
-PTH causes calcium to move from the bones, kidneys, and intestines into the blood
Two parts of adrenal glands
Medulla and cortex
Adrenal medulla hormones
Epinephrine and norepinephrine
-Augment the fight or flight response
-Prepare the body for physical activity by increasing heart rate and blood pressure etc.
Adrenal cortex hormones
Mineralocorticoids
-Aldosterone, which acts on the kidney to control fluid balance
Pancreas endocrine function
Islets of Langerhans
-Contain alpha beta and Delta cells
Alpha cells
-Secrete glucagon
-Stimulates the liver to start gluconeogenesis releasing glucose into the blood stream between meals
Beta cells
-Secrete insulin
-Stimulates cells to absorb glucose and amino acids after eating
Delta cells
-Secrete somatostatin
-Inhibits the release of both glucagon and insulin when not needed, as well as the release of growth hormone
After eating, This happens to blood glucose levels
-Glucose levels rise
-High glucose levels stimulate beta cells to secrete insulin
Insulin causes two things
-Stimulates cells to take up more glucose
-Causes the liver to take up glucose and store it as glycogen
What happens When blood glucose levels drop below a certain point
-Alpha cells release glucagon into the blood
-Glucagon stimulates the liver to break down stored glycogen into glucose which it releases into the bloodstream
Ovarian follicle secretes
Estrogen
-Promotes the development of female sex characteristics
What is corpus luteum and what does it secrete
Tissue left behind after an ovarian follicle ruptures
-Secretes progesterone
-Works with oestrogen to maintain uterine lining during pregnancy
What are prostaglandins
Lipid molecules that integrate the activities of other cells
How are prostaglandins different from hormones
They are released within the tissue where they are produced so they only influence neighbouring cells, not distant organs
