Biology Chapter 7: The Endocrine System Flashcards
Chemoreceptors
including those of the taste buds in the tongue, olfactory receptors in the nose, carotid and aortic bodies, and chemoreceptor trigger zone of the medulla, are neurons involved in sensing molecules dissolved in gasses or liquids.
Nociceptors
mediates the perception of pain.
are a subclass of mechanoreceptors located in the walls of blood vessels, as well as the atrial and ventricular walls of the right side of the heart. They detect stretch, signaling changes in luminal pressure.
Baroreceptors
Mechanoreceptors
neurons that respond to mechanical pressure or distortion. Cutaneous mechanoreceptors are responsible for somatosensation, while those embedded in muscles and ligaments are responsible for sensing muscular stretch and load, including in the afferent arm of a number of reflex arcs.
How do steroid hormones regulate gene expression?
bind with nuclear receptors that regulate expression through transcription factors
Oligodendrocytes
principal myelinating cells in the CNS
Schwann cells
principal myelinating cells in the PNS
Aldosterones effect on potassium
while K+ is technically a salt, aldosterone’s effect is to increase sodium reabsorption and enhance potassium excretion, altering the relative levels of these salts in the bloodstream
What happens when sensitivity of insulin decreases
Insulin resistance. Need MORE insulin for glucose uptake (like in the case of diabetes)
What happens when sensitivity of insulin increases
Don’t need a ton of insulin for glucose uptake (like in the case of trained endurance athletes)
is the anterior or posterior pituitary gland directly connected to the hypothalamus?
posterior.
The hypothalamus produces hormones that are stored and released by the posterior pituitary.
These hormones travel down axons of neurosecretory cells from the hypothalamus into the posterior pituitary.
How does the hypothalamus communicate with the anterior pituitary gland?
t communicates with the anterior pituitary through the hypophyseal portal system, which is a network of blood vessels.
True or False: The posterior pituitary (neurohypophysis) does NOT produce hormones
TRUE
The posterior pituitary (neurohypophysis) does NOT produce hormones, because hormones released from the posterior pituitary are actually produced by the hypothalamus.
True or false: The posterior pituitary only stores and secretes hormones that were produced by the hypothalamus.
TRUE
Hormones secreted and stored by Posterior pituitary gland
Hormones produced and secreted from anterior pituitary gland
Hormones produced and secreted from hypothalamus
these hormones are synthesized in the hypothalamus, and either act on the anterior pituitary or are transported to the posterior pituitary for storage and release.
Calcitonin is a peptide hormone secreted by the
thyroid gland
Cortisol release pathway
Hypothalamus (CRH) ➡️ anterior pituary gland (ATCH) ➡️ adrenal cortex (cortisol)
Reproductive Axis pathway
Shows the Two Major Ovarian Functions:
Follicular Phase:
FSH stimulates follicle growth.
Follicle produces estrogen (estradiol).
Estrogen provides positive feedback (+) on the hypothalamus (only during the mid-cycle surge for ovulation).
Luteal Phase:
After ovulation, the follicle transforms into the corpus luteum, which secretes progesterone.
Progesterone provides negative feedback (-) on the hypothalamus and pituitary to regulate hormone levels.
Shows Both Positive and Negative Feedback Loops:
Estrogen → Positive Feedback (+) on GnRH & LH (during ovulation).
Progesterone → Negative Feedback (-) on GnRH & LH (to prevent another ovulation in the same cycle).
This dynamic control is essential for menstrual cycle regulation.
Difference between GnRH and GHRH
GnRH (Gonadotropin-releasing hormone) stimulates the release of LH and FSH for reproductive function, while GHRH (Growth hormone-releasing hormone) stimulates the release of GH for growth and metabolism. 🚀
