Chapter 19 Alvins Notes Flashcards
What is the primary difference between endocrine and exocrine glands?
Endocrine glands secrete hormones directly into the bloodstream (no ducts), while exocrine glands use ducts to secrete substances like sweat or oil to specific locations.
Name two examples of exocrine glands and their functions.
Sweat glands (secrete sweat to cool the body) and oil glands (secrete sebum to moisturize and protect the skin).
How do endocrine glands deliver hormones to target organs?
They release hormones into the bloodstream, which travel to target organs.
Which part of the pituitary gland is controlled by the hypothalamus through releasing and inhibiting hormones?
The anterior pituitary (adenohypophysis).
What is the role of growth hormone-releasing hormone (GHRH)?
It stimulates the anterior pituitary to release growth hormone, which affects the entire body.
What hormones are stored in the posterior pituitary, and where are they produced?
Oxytocin and antidiuretic hormone (ADH) are stored in the posterior pituitary but produced in the hypothalamus.
Describe the functions of oxytocin.
Oxytocin stimulates uterine contractions during labor, milk ejection during breastfeeding, stops uterine bleeding post-delivery, and promotes parental bonding.
What is the synthetic version of oxytocin called?
Pitocin.
What are the two primary hormones secreted by the thyroid gland, and what is their function?
Tetraiodothyronine (T4) and triiodothyronine (T3) increase metabolism in the body.
Which thyroid hormone reduces blood calcium levels?
Calcitonin.
What is the role of calcitonin in calcium regulation?
It reduces blood calcium levels by opposing the action of parathyroid hormone.
What are the three main categories of hormones secreted by the adrenal cortex?
Mineralocorticoids (e.g., aldosterone), glucocorticoids (e.g., cortisol), and androgens (sex hormones).
What is the function of aldosterone, and what conditions can result from its overproduction?
Aldosterone conserves sodium, excretes potassium, and retains water, increasing blood volume and pressure. Overproduction can lead to hypernatremia (high sodium) and hypokalemia (low potassium), as seen in Cushing’s syndrome.
What is cortisol commonly referred to as, and what is its role in the body?
Cortisol is the primary stress hormone and helps with glucose synthesis, glycogen formation, and raising blood glucose levels.
Which hormones are released by the adrenal medulla, and what is their role in the sympathetic response?
Epinephrine (adrenaline) and norepinephrine (noradrenaline) increase heart rate, blood glucose usage, and prepare the body for a “fight or flight” response.
What hormone does the pineal gland secrete, and what is its function?
Melatonin, which regulates sleep-wake cycles.
What hormone does the thymus secrete, and what is its role in the immune system?
Thymosin, which matures T-cells (a type of white blood cell critical for immune response).
Where do white blood cells mature before they move to the thymus?
In the red bone marrow.
What is the role of insulin, and how does it lower blood sugar levels?
Insulin helps glucose enter cells, reducing blood sugar levels.
How does type 1 diabetes differ from type 2 diabetes in terms of insulin production and function?
Type 1 diabetes involves destruction of beta cells, resulting in no insulin production. Type 2 diabetes involves defective insulin receptors, so cells cannot properly use insulin.
Which pancreatic cells secrete glucagon, and what is its function?
Alpha cells secrete glucagon, which raises blood sugar levels by stimulating glycogen breakdown in the liver.
What hormones are secreted by the ovaries, and what are their primary roles?
Estrogen and progesterone regulate the menstrual cycle and support pregnancy.
What hormone is secreted by the testes, and what is its function?
Testosterone, which develops male secondary sexual characteristics and aids in sperm production.
Trace the pathway of air from the nasal concha to the alveoli.
Nasal concha → pharynx → larynx → trachea → bronchi → bronchioles → alveoli.
What is the primary function of alveoli in the respiratory system?
The alveoli facilitate gas exchange by allowing oxygen to enter the bloodstream and carbon dioxide to exit.
