Endocrinology

What do cells secrete for cell-cell communication?

Chemical signals or hormones.

How are hydrophilic hormones released from cells?

Via exocytosis.

What is paracrine signaling?

Hormone released into interstitial fluid to stimulate nearby cells.

What type of signaling involves mutual binding between two membranes?

Contact dependent signaling.

What is synaptic transmission?

A nerve cell conveys neurotransmitter to a postsynaptic cell.

What do pheromones do in cell signaling?

They are secreted into the external environment to target cells in other organisms of the same species.

What is direct coupling in cell communication?

Cytoplasm of adjacent cells are connected for hormone diffusion.

What type of tissue is the posterior pituitary considered?

Nerve tissue.

What do the two types of nerve cells in the hypothalamus secrete?

One secretes ADH/AVP and the other releases oxytocin.

What is the role of oxytocin during childbirth?

Stimulates the muscles of the uterus for contractions.

What initiates the positive feedback loop in breastfeeding?

A hungry baby stimulates breastfeeding.

What role does estrogen play in mammary gland development?

Causes growth of mammary gland tissue.

How many hormones does the anterior pituitary release?

Eight hormones.

What are tropic hormones?

Hormones that affect endocrine organs that secrete other hormones.

What hormones are considered tropic hormones?

FSH, LH, TSH, ACTH, GH.

What triggers the release of FSH and LH from the anterior pituitary?

GnRH (gonadotropin releasing hormone) from the hypothalamus.

What do gonads produce?

Gametes and endocrine hormones.

What is the primary function of FSH in males?

Promotes spermatogenesis.

How does testosterone affect the anterior pituitary?

It inhibits the release of LH.

What hormone does the corpus luteum secrete?

Estrogen and progesterone.

What occurs if fertilization does not happen?

The corpus luteum degenerates to scar tissue after ~10 days.

What characterizes the follicle maturation process?

Primary follicles maturing into secondary follicles.

What is ovulation?

The rupture of the follicle, releasing the oocyte.

What triggers the LH surge during the menstrual cycle?

Estrogen surge from the growing follicle.

What is the role of hCG in pregnancy?

It mimics LH to save the corpus luteum and maintain hormone production.

What hormone stimulates the thyroid gland?

TSH (Thyroid Stimulating Hormone).

What are the effects of hyperthyroidism?

High temperature, sweating, irritability.

What causes hypothyroidism in infants?

Congenital iodine deficiency syndrome.

What regulates ACTH release?

CRH (corticotropin releasing hormone).

What hormones are released from the adrenal cortex?

Mineralocorticoids, glucocorticoids, and sex steroids.

What is the main glucocorticoid in humans?

Cortisol.

What does cortisol do during stress?

Promotes gluconeogenesis and muscle catabolism.

What is the primary role of GH (Growth Hormone)?

Stimulates growth in muscles and bones.

What is the effect of prolactin?

Stimulates growth of mammary glands and secretion of milk.

What does MSH (Melanocyte Stimulating Hormone) do?

Disperses pigment in melanocytes.

What are endorphins?

Naturally occurring opiates that inhibit pain and induce euphoria.

What triggers the release of IGFs from the liver?

Growth Hormone (GH).

What is the role of inhibin in male reproductive function?

It inhibits FSH release from the anterior pituitary.

How many endocrine cell types does the anterior pituitary have?

Seven endocrine cell types.

What does the theca cell in the ovary secrete?

Testosterone.

What does FSH stimulate in females?

Follicle growth and maturation.

What effect does estrogen have during the menstrual cycle?

Inhibits FSH and LH release.

What triggers ovulation around day 14 of the cycle?

LH surge.

What happens to the endometrium if there is no fertilization?

It undergoes necrosis and menstruation begins.

What hormone is responsible for maintaining the endometrium during pregnancy?

Progesterone.

What is the primary effect of aldosterone?

Sodium ion and water reabsorption.

What are the symptoms of adrenal gland disorders?

Hypertension, fatigue, and metabolic issues.

How does cortisol affect immune function?

It acts as an immunosuppressant.

What happens during puberty regarding GnRH?

GnRH production begins.

Which hormones regulate the menstrual cycle?

Estrogen and progesterone.

What does the hypothalamus control in relation to the pituitary gland?

It controls the release of hormones through releasing and inhibiting hormones.

What are the effects of cortisol on glucose metabolism?

It ensures glucose is available by stimulating gluconeogenesis.

What is the result of elevated levels of GH during childhood?

Gigantism.

What is the result of excess GH in adults?

Acromegaly.

What does the anterior pituitary secrete in response to hypothalamic hormones?

Tropic and non-tropic hormones.

What is a common treatment for adrenal insufficiency?

Glucocorticoid therapy.

What cellular process does insulin-like growth factor (IGF) promote?

Cell division and protein synthesis.

What receptor does testosterone bind to in target cells?

Androgen receptor.

What characterizes the corpus luteum?

It is a temporary endocrine organ.

What negative feedback mechanism exists in testosterone regulation?

Testosterone inhibits LH and GnRH release.

What does the ovaries' granulosa cell do?

Surrounds and nourishes the developing gamete.

What is the result of endorphin release during pain?

Pain inhibition and euphoria induction.

How are thyroid hormones synthesized?

From tyrosine in thyroglobin molecules.

What happens to FSH and LH levels during the mid-cycle surge?

They increase leading to ovulation.

What role does estrogen play in the feedback loop on the pituitary?

It inhibits FSH and LH release.

What stimulates mammary gland growth during pregnancy?

Prolactin and estrogen.

Which cells in the testes produce testosterone?

Leydig cells.

How is spermatogenesis promoted in the testes?

By FSH binding to Sertoli cells.

When does the menstrual cycle begin?

At the onset of menstruation.

What connects the hypothalamus to the anterior pituitary?

The portal vein system.

What is the response of the body to prolonged stress?

Increased cortisol production.

What enables gap junctions for direct coupling?

The cytoplasm of adjacent cells being connected.

Which hormone is released in response to stress?

Epinephrine.

What stimulates the production of causing milk letdown?

Oxytocin.

What do the remnants of the follicle after ovulation become?

The corpus luteum.

How does estrogen affect LH and FSH secretion during the late cycle?

Estrogen inhibits their release.

What is the lifespan of the corpus luteum if fertilization does not occur?

~10 days before degeneration.

What signals the secretion of glucagon?

Low blood glucose levels.

What hormone maintains the endometrium in pregnancy?

Progesterone.

Why does the female cycle have phases?

To prepare for possible fertilization.

What does high levels of progesterone do to the menstrual cycle?

It prevents ovulation during pregnancy.