Endocrine System Flashcards
(24 cards)
Question: What is the primary means of communication for the nervous system?
Answer: Electrical impulses and neurotransmitters.
Question: How do hormones communicate in the endocrine system?
Answer: Hormones communicate through the bloodstream.
Question: What is the typical response time for the nervous system?
Answer: The nervous system reacts quickly, usually within 1-10 minutes.
Question: Describe the type of effect caused by the endocrine system.
Answer: The effect is widespread and general, reacting slowly from seconds to days and continuing even after the stimulus ends.
Question: What are steroid hormones derived from, and where are they secreted?
Answer: Steroid hormones are lipid-derived from cholesterol and are secreted by the gonads and adrenal cortex.
Question: Give two examples of peptide/protein hormones.
Answer: Insulin and glucagon.
Question: What type of hormones are derived from specific amino acids, and can you name an example?
Answer: Biogenic amines; an example is epinephrine.
Question: List three functions of hormones.
Answer: Regulate growth and development, control functions of various tissues, and support reproductive functions.
Question: How do steroid hormones initiate their actions in target cells?
Answer: Steroid hormones directly enter cells and affect gene activation.
Question: Which type of hormones use second messengers for their action?
Answer: Amine and Peptide hormones.
Question: What is the primary purpose of negative feedback in the endocrine system?
Negative feedback reverses changes caused by stimuli to maintain homeostasis.
Question: Provide an example of positive feedback.
Answer: Oxytocin release during childbirth.
Question: What is the function of the hypothalamus in the endocrine system?
Answer: The hypothalamus serves as the master control for involuntary body functions and hormone regulation.
Question: Name one hormone produced by the posterior lobe of the pituitary gland.
Answer: Oxytocin or Antidiuretic hormone (ADH).
Question: What is the role of insulin produced by the pancreas?
Answer: Insulin lowers blood glucose levels.
Answer: Insulin lowers blood glucose levels.
Question: Which hormone does the pineal gland secrete, and what does it regulate?
Answer: The pineal gland secretes melatonin, which regulates the sleep cycle and circadian rhythms.
Question: What hormone does the thymus produce and what is its role?
Answer: The thymus regulates lymphocytes.
Question: What is the function of leptin, and where is it produced?
Answer: Leptin regulates appetite and is produced from adipose tissue.
What are the main differences between the nervous system and the endocrine system?
The nervous system coordinates rapid and precise responses to stimuli using action potentials, while the endocrine system regulates body functions, maintains homeostasis, and provides long-term control using chemical signals (hormones). The nervous system uses electrical impulses and neurotransmitters for communication, whereas the endocrine system uses hormones. The effects of the nervous system are relatively local and specific, reacting quickly to stimuli, while the endocrine system has widespread and general effects, reacting more slowly to stimuli. [page 6-7]
What are the three classes of hormones?
The three classes of hormones are: 1) Steroids, which are lipids derived from cholesterol and can be taken orally. Examples include estrogen, progesterone, testosterone, and adrenal cortex hormones. 2) Protein/Peptide hormones, which are short or long chains of amino acids, secreted by glands like the pituitary and parathyroid. Examples include FSH, LH, ADH, oxytocin, insulin, glucagon, and growth hormone. 3) Biogenic amines, which are small molecules synthesized by altering the structure of a specific amino acid. Examples include thyroxine, epinephrine, and prostaglandin.
How are hormones transported in the body?
Most hormones are directly released into the bloodstream and circulate in very low concentrations. Some require a carrier substance, like a protein molecule, to act as a hormone reservoir for constant level and protection from chemical breakdown. There are specific carrier proteins that bind one particular hormone, such as Cortisol binding globulin, Thyroxine binding globulin, and Sex hormone binding globulin. General carrier proteins like Albumin and Transthyretin bind hormones generally.
What is the role of the hypothalamus in the endocrine system?
The hypothalamus serves as a regulator of the endocrine system that controls the pituitary gland. It is connected to the pituitary gland by the pituitary stalk and carries out its function by secreting regulatory hormones that influence the secretory function of the anterior pituitary, synthesizing Oxytocin and Antidiuretic hormone (ADH) which are stored in the posterior pituitary, and overseeing the hormonal activity of the adrenal medulla.
What are the functions of insulin secreted by the pancreas?
Insulin exerts its effect by binding to specific receptors on the surface of target cells. It has a continuous basal level of secretion throughout 24 hours, independent of food intake. Insulin increases hepatic glycogen stores, inhibits glycogenolysis and gluconeogenesis in the liver, stimulates glycogen synthesis and glycolysis, increases glucose uptake in muscle, inhibits lipolysis, increases lipogenesis, and stimulates the uptake of amino acids in muscle, increasing protein synthesis.
What are the effects of epinephrine and norepinephrine secreted by the adrenal medulla?
Epinephrine and norepinephrine are released during “fight & flight” situations to increase the body’s capability for vigorous muscle activity. They increase heart rate, contractions, and cardiac output, cause vasodilation in skeletal muscles and lung airways, vasoconstriction in internal organs and skin, increase mental alertness, glycogenolysis in liver and muscle, lipolysis in adipose tissue, decrease insulin secretion, and increase glucagon secretion.
