Lecture 13: Endocrine System Part 2 Flashcards
What is the function of the pineal gland?
It produces and releases melatonin hormone in response to darkness. It regulates sleep, circadian rhythms and seasonal mood changes.
What is seasonal affective disorder?
A form of depression that occurs in some individuals during the winter due to reduced exposure to sunlight.
What are some ways in treating sadness?
- Light therapy
- Cognitive behavioral therapy
- Medication (SSRIs)
Which two hormones are released by the thyroid gland?
- Thyroid hormone (regulates metabolic rate).
- Calcitonin (regulates calcium levels in the blood).
Which cells in the thyroid make which hormone?
Follicle cells: Responsible for making thyroid hormone.
Parafollicular cells: In between the follicles which make calcitonin.
What is the function of the thyroid hormone (T3 and T4)?
Regulates our metabolic rate and production of heat.
Make cellular energy in mitochondria and promote protein synthesis within cells.
What is the characteristic of thyroid hormone at a molecular level?
Both T3 and T4 are hydrophobic. Only differ in the number of iodine atoms in the molecule.
What are the disorders caused by abnormal TH levels?
- Hypothyroidism (metabolism too slow)
- Hyperthyroidism (metabolism too fast)
What are some impacts of hypothyroidism?
- Fatigue, memory impairment, depression
- Weight gain, constipation
- Enlarged thyroid gland
What is Hashimoto’s disease?
An autoimmune disorder. Immune system targets and destroys cells in the thyroid gland including T3 and T4 hormones.
(Treatable with Synthroid)
What are some impacts of hyperthyroidism?
- Increased heart rate
- Muscle cramps/weakness
- Warm, moist skin, increased body temperature
What is Grave’s disease?
Antibodies are produced that mimic TSH, they can bind to TSH receptors in the thyroid gland cand cause them to release more TH than is necessary. (autoimmune disorder - hyperthyroidism)
What are the functions of calcitonin hormone?
- Inhibits breakdown of bone matrix (calcium phosphate) by osteoclasts.
- Promotes building up of bone matrix by osteoblasts.
What are the functions of parathyroid glands?
- Stimulate osteoclasts to breakdown calcium phosphate matrix of bone.
- Stimulate intestines to absorb more calcium.
- Stimulates reabsorption of calcium in kidneys from filtrate.
What is the connection of parathyroid hormone and vitamin D?
PTH indirectly promotes calcium intestinal absorption by activating an enzyme in the kidneys that converts inactive vitamin D into its active form calcitriol.
What are the two regions of the adrenal gland and their functions?
- Adrenal cortex: Makes hydrophobic hormones such as male and female sex hormones.
Long term stress response (cortisol) - Adrenal medulla: Short term stress response hormones (epinephrine and norepinephrine)
What are the 3 different classes of steroid hormones made by adrenal cortex?
- Mineralocorticoids
(Maintain blood plasma ion and water balance)
2.Glucocorticoids (Cortisol) release of glucose in the bloodstream - Sex hormones
What is the function of Aldosterone?
Produced in outer adrenal cortex.
Regulates sodium and potassium ion concentrations.
Stimulates Na+ reabsorption back into bloodstream and K+ secreted as urine.
What is the function of cortisol?
Part of long term stress response which diminishes a body’s immune system. Mobilize stored nutrients for the body to use as energy.
(Active in the day.)
What is the function of epinephrine and norepinephrine?
Part of short term response which stimulates sympathetic nervous system.
- Increases heart and respiratory rate
- Increase glucose and oxygen to the brain and muscles.
Which are the two hormones released by the pancreas?
Glucagon: Increases blood glucose levels.
Insulin: Decreases blood glucose levels.
Within the pancreatic islet, what is the function of alpha and beta cells?
Alpha cells: Make and release glucagon
Beta cells: Make and release insulin
What is gluconeogenesis?
Convert stored glycogen into glucose and release it into the blood stream as well as synthesize new glucose molecules from fat and/or amino acid precursors
What is the difference between type 1 and type 2 diabetes?
Type 1 diabetes: An autoimmune disease that destroys the cells in the pancreas that make insulin. Insulin must be taken by injection. (EARLY)
Type 2 diabetes: Later onset (over 45) Body becomes less responsive to insulin. Poor diet, sedentary lifestyle and obesity make an individual more susceptible.
