Hormone Basics
Identify the solubility of steroid and peptide hormones.
Steroid: lipid soluble/non-water soluble
Peptide: non-lipid soluble/water soluble
The pineal gland secretes this hormone that regulates sleep cycles.
Melatonin
This type of feedback loop maintains homeostasis by reversing a change.
Negative feedback loop
This hormone stimulates uterine contractions during childbirth.
Oxytocin
This disorder is caused by a lack of or a resistance to insulin.
Diabetes mellitus
Identify which type of molecule and steroid and peptide hormones are derived from.
Steroid- cholesterol
Peptide- amino acids
The thyroid gland secretes these hormones.
T3, T4, Calcitonin
Describe the differences between negative and positive feedback loops and give an example for each in the endocrine system.
Negative- change triggers a response that counters the initial change, maintaining homeostasis (ex. insulin/glucagon release to regulate blood glucose)
Positive- change triggers a response that amplifies the change (ex. oxytocin during labor and breastfeeding).
These hormones increase blood flow to muscles and the heart, dilates airways, and are released by a neural response.
Epinephrine/norepinephrine
Fatigue, cold intolerance, and weight gain can indicate this disorder.
Hypothyroidism
Identify the location of receptors for both steroid and peptide hormones
Steroid- inside cell (nucleus or cytoplasm)
Peptide- cell membrane (membrane receptors)
Name the hormones secreted by both the anterior and posterior pituitary.
Anterior- FSH, LH, ACTH, GH, PRL, TSH
Posterior- Oxytocin, ADH
In the HPT axis, the thyroid gland produces T3 and T4 in response to this pituitary hormone.
Thyroid-stimulating hormone (TSH)
Identify which pancreatic hormone is released after you eat a meal. What is its function and which cells secrete it?
Insulin- decreases blood glucose, beta cells
Bulging eyes, weight loss, and heat intolerance are symptoms of this disorder.
Hyperthyroidism
Name two ways hormone effectiveness can be influenced in the body.
Hormone concentration and presence of other hormones
List and describe the hormones released by the adrenal gland. Include which part of the adrenal gland they are released from.
Epi/Norepi: short-term stress (fight-or-flight response), adrenal medulla
Cortisol: long-term stress, zona fasciculata
Aldosterone: Na+ reabsorption in kidneys, zona glomerulosa
Androgens: secondary sex characteristics, zona reticularis
Identify and describe the three types of stimuli that trigger hormone release.
Humoral: changes in blood levels of ions or nutrients
Hormonal: one hormone causes another hormone to be release
Neural: nerve impulses from the nervous system
Describe the effects of anti-diuretic hormone (ADH).
Increases water reabsorption in the kidneys, maintains blood pressure and blood volume in kidneys.
Describe the 3 growth hormone pathologies.
Dwarfism- hyposecretion BEFORE growth plates fuse
Gigantism- hypersecretion BEFORE growth plates fuse
Acromegaly- hypersecretion AFTER growth plates fuse
Explain why peptide hormones act faster than steroid hormones.
They activate second messenger systems rather than altering gene transcription.
The thymus secretes hormones that help regulate this system.
Immune system
Explain the positive feedback loop involved in childbirth.
Uterine contractions-->oxytocin release-->stronger contractions-->more oxytocin until delivery
Describe the function of the parathyroid hormone and how it does its job.
Increases calcium levels by stimulating osteoclast activity
Explain the cortisol pathologies and the symptoms involved.
Addison's disease- hyposecretion: low blood pressure, fatigue, hyperpigmentation of skin, weight loss
Cushing's syndrome- hypersecretion: "moon-face," high bp, hyperglycemia, weak bones and immune system