Chapter 18: Endocrine System Flashcards
What makes up endocrine system organs?
- Endocrine Glands
- Neuroendrocrine
- Tissues/Cells
What 5 glands make up the endocrine system?
- pituitary gland
- thyroid gland
- parathyroid gland
- adrenal gland
- pineal glands
What tissues and cells are in the endocrine system?
- Pancreas
- Gonads (ovary/testis)
- placenta
What are the two lobes of the pituitary gland?
- Anterior (adenohypophysis)
- Posterior (neuropophysis)
What 7 hormones are released from the anterior pituitary gland?
- Thyroid Stimulating Hormone (TSH)
- Follicular Stimulating Hormone (FSH)
- Leutinizing Hormone (LH)
- Adrencorticotropic Hormone (ACTH)
- Prolactin (PRL)
- Melanocyte Stimulating Hormone (MSH)
- Growth Hormone (GH)
Which 2 hormones are stored in the posterior pituitary?
- Antidiuretic Hormone (ADH)
- Oxytocin (OXT)
How are antidiuretic hormone (ADH) & oxytocin (OXT) released from the posterior pituitary gland?
- action potentials from hypothalamus trigger release of ADH & OXT
- ADH & OXT transported to posterior pituitary through anterograde transportation
Where is the pituitary gland located?
- in sella turcica
- connected to hypothalamus by infundibulum (right above hypothalamus)
What kinds of hormones does the pituitary gland release?
Peptide hormones (9)
Function of hypothalamus in endocrine system
- secrete or inhibit “RH” (releasing) or “IH” (inhibitory) hormones
Function of ADH (antidiuretic hormone)
helps reabsorb and keep water in body
Where is ADH (antidiuretic hormone) released from?
Hypothalamus
What is ADH’s target organ?
Kidneys
When is ADH released?
released in response to decrease in blood volume/blood pressure or an increase in solute in the blood
- more solute in blood, more dehydrated, more water body wants to keep
How does ADH travel through the body?
- osmoreceptors sense osmolarity in hypothalamus
- if solute conc. is too high, release ADH
- ADH travels to kidneys & helps reabsorb water
- makes person thirsty
How does ADH production stop?
- negative feedback loop
1. osmoreceptors sense adequate amt of water
2. signal to hypothalamus
3. hypothalamus ends production of ADH
What is diabetes insipidus?
- large volumes of urine secreted
Due to… - low conc. of ADH (don’t reabsorb H2O)
- ADH does not bind correctly
- not enough receptors
Function of Oxytocin
increases strength of smooth muscle contractions
(positive feedback)
When is oxytocin inhibited?
- when no more pressure
ex. uterus, mammary glands, sperm duct
What are tropic hormones?
affect release of hormones from other glands (help release 2nd hormone)
ex. TSH
Hormones that release a 2nd hormone?
Tropic Hormones
Thyroid Stimulating Hormone (TSH)
- Function?
- Location of Release?
- Hormone that Releases?
- Loop of Release?
- Function: stimulates thyroid gland
- Location of Release: Anterior Pituitary
- Hormone that Releases: TRH (thyroid releasing hormone)
- Loop of release:
- stress causes hypothalamus to release TRH
- TRH travels to anterior pituitary through hypophyseal portal system
- TRH stimulates anterior pituitary to release TSH (thyroid stimulating hormone)
- TSH travels through blood to thyroid gland
- TSH stimulates thyroid gland to secrete T3 & T4
- T3 & T4 are stored in thyroglobulin in thyroid follicles until ready to be secreted
- T3 & T4 are secreted into blood & bind to mitochondria & increase metabolic rate (use more ATP)
- increase heat production
Do kids or adults produce more TSH?
Kids - less cold than adults (warmer due to body burning/using more ATP)
What do the numbers in T3 & T4 means?
the # of iodines attached to the hormone
ex. T3 (3 iodines attached)
T4 (4 iodines attached)