Hormones and Endocrine Signaling

what are the two hormones secreted by the posterior pitutitary glad?

oxytocin and vasopressin (ADH antidiuretic hormone)

how are hormones distributed within the posterior pituitary?

cell bodies of the neurons are located in the hypothalamus → the neurosecretory cells’ axons (the tube-like portion of the neuron) extend down the pituitary stalk into the posterior pituitary gland→ blood capillaries are attached to the neuron terminal and circulate to the rest of the body

the hormones flow through this outlined path from the hypothalamus to the pituitary stalk to the posterior pituitary gland until they are dispersed through the body.

what is the purpose of the oxytocin hormone?

• stimulates breast milk flow after pregnancy

• stimulates uterine contractions during birth

what is the purpose of the ADH (aka Vasopressin) hormone?

• increases water conservation by kidneys

• constricts blood vessels

how are hormones distributed within the anterior pituitary?

cell bodies AND axons of hypothalamic neurosecretory cells are located in the hypothalamus → their axons extend to the top of the pituitary stalk → the axons release hormones to be received by a blood capillary system → the blood capillary system goes from the top of the pituitary stalk to the anterior pituitary gland → once the hormones are transferred via the blood capillary system and arrive in the anterior pituitary gland, they exit the capillaries and surround a group of endocrine cells (cells that release hormones into the blood)→ hormones are released into the blood by non-neural endocrine cells in the anterior pituitary

what is the difference between endocrine cells and nerve cells?

endocrine cells release hormones into the blood and nerve cells are involved in electrical signaling

what are releasing hormones

they are hormones released by the neurosecretory cells in the hypothalamus

what is the function of releasing hormones?

they trigger the release of other hormones by endocrine cells in the anterior pituitary

what are tropic hormones

• they are a subset of hormones secreted by the anterior pituitary cells

what are the four tropic hormones?

• Follicle stimulating hormone (FSH)

• Luteinizing hormone (LH)

• Adrenocorticotropic hormone (ACTH)

• Thyroid stimulating hormone (TSH)

what is the purpose of the FSH (follicle stimulating hormone) in the anterior pituitary gland?

• growth of follicles (sacs of fluid in ovaries containing developing egg) in females

• sperm production in males

what is the purpose of the LH (luteinizing hormone) in the anterior pituitary gland?

controls the menstrual cycle and causes ovulation

what is the purpose of the ACTH (adrenocorticotropic hormone) in the anterior pituitary?

it stimulates the release of adrenaline (fight or flight hormone) from the adrenal gland (in the kidneys)

what is the purpose of the TSHormone

it stimulates release of thyroid hormone from the thyroid gland

what does FLAT stand for?

• the four tropic hormones released within the anterior pituitary gland

Follicle stimulating hormone (FSH)

Luteinizing hormone (LH)

Adrenocorticotropic hormone (ACTH)

Thyroid stimulating hormone

what is the order of flow for the different types of hormones within the hypothalamus?

hypothalamus releases “releasing hormones” → releasing hormones are accepted by the anterior pituitary → endocrine non-neural cells in anterior pituitary release tropic hormone → tropic hormone is released into the bloodstream and binds to any cells that have receptors for that protein (called a peripheral endocrine gland) → gland then secretes its own hormone