L10 Endocrine System Flashcards
The endocrine system is a widely distributed group of glands that secrete hormones to do what?
Maintain homeostasis
All of the glands are called?
“Ductless”
- they don’t have to be specifically attached to a duct as they secrete their hormones directly into the blood
- there are target tissues around the body that receive these hormones
- the hormones directly attach to receptors on the target tissue to have an effect
What are the 3 glands in the “cranial cavity”?
- hypothalamus
- pineal gland
- pituitary gland
The hypothalamus is really part of the nervous system, but it controls what gland?
Pituitary gland, which is part of the endocrine system
Where is the hypothalamus located?
In the diencephalon of the brain
- the pituitary gland is below the hypothalamus
How many lobes does the pituitary gland have?
- anterior lobe in the front
- posterior lobe in the back
Where is the pituitary gland located?
In boney landmark called sella turcica in the sphenoid bone
- the gland is well protected inside the base of the skull by bone
How many hormones does the anterior lobe of the pituitary gland release?
6
What are the 6 hormones that the anterior lobe in the pituitary gland release?
- GH (growth hormone, aka somatotropin)
- TSH (thyroid stimulating hormone)
- ACTH (adrenocorticotropic hormone)
- FSH (follicle stimulating hormone)
- LH (luteinizing hormone)
- PRL (prolactin)
What does the GH (growth hormone, aka somatotropin) do? (anterior)
Promotes growth of all body tissues
What does the TSH (thyroid-stimulating hormone) do? (anterior)
Stimulates thyroid gland to produce thyroid hormones
What does the ACTH (adrenocorticotropic hormone) do? (anterior)
Stimulates adrenal cortex to produce cortical hormones; aids in protecting body in stress situations (injury, pain)
What does the FSH (follicle-stimulating hormone) do? (anterior)
Stimulates growth and hormonal activity of ovarian follicles; stimulates growth of testes; promotes sperm cell development
- anterior pit gland
What does the LH (luteinizing hormone) do? (anterior)
Causes development of corpus luteum at the site of ruptured ovarian follicle in female; stimulates testosterone secretion in male
What does the PRL (prolactin) hormone do? (anterior)
Stimulates milk secretion by mammary glands
What does the ‘ADH’ hormone do? (posterior)
Promotes water reabsorption in kidneys tubules; causes blood vessels to constrict
What does the ‘oxytocin’ hormone do? (posterior)
Causes uterine construction; causes milk ejection from mammary glands
The ‘T3’ and the ‘T4’ do? (thyroid)
Increase metabolic rate and heat production, influencing both physical and mental activities; required for formal growth
What does the ‘PTH (parathyroid hormone)’ do? (parathyroid)
Regulates calcium exchange between blood and bones; increases blood calcium level
What does the ‘cortisol’ hormone do? (adrenal cortex)
Aids in metabolism of carbohydrates, proteins, and fats; active during stress
What does the ‘aldosterone’ hormone do? (adrenal cortex)
Aids in regulating electrolytes and water balance
What does the ‘epinephrine’ hormone do? (adrenal medulla)
Response to stress; increases respiration; blood pressure, and heart rate
What does the ‘insulin’ hormone do? (pancreatic islet)
Aids glucose transport into cells; required for cellular metabolism of nutrients, especially glucose; decreases blood glucose levels
What does the ‘glucagon’ hormone do? (pancreatic islet)
Stimulates liver to release glucose, thereby increasing blood glucose levels
What does the ‘melatonin’ hormone do? (pineal gland)
Regulates mood, sexual development, and daily cycles in response to environmental light
What does the ‘testosterone’ hormone do? (testis gland)
Stimulates growth and development of sexual organs plus development of secondary sexual characteristics; stimulates maturation of sperm cells
What does the ‘estrogen’ hormone do? (ovary gland)
Stimulates growth of primary sexual organs and development of secondary sexual characteristics
What does the ‘progesterone’ hormone do? (ovary gland)
Prepares uterine lining for implantation of fertilized ovum; aids in maintaining pregnancy; stimulates development of mammary gland’ secretory tissue
How many hormones does the posterior lobe of the pituitary gland release?
2
What are the 2 hormones that the posterior lobe in the pituitary gland release?
- Antidiuretic hormone (ADH)
- Oxytocin
What does the ‘antidiuretic hormone’ do?
Helps with water conservation by kidneys and vasoconstriction of blood vessels
When ADH is released, it causes the kidneys to conserve water, which happens through vasoconstriction of blood vessels in the area.
What does the ‘oxytocin hormone’ do?
Primarily a hormone that acts on the female reproductive system
Oxytocin stimulates uterine contractions, which initiates labor.
After the baby’s born, oxytocin promotes “milk let down” by the breasts.
Milk letdown is when the hormone kicks into gear and the mammary glands in the ducts in your breast, relax, to let down milk for feeding
Where is the “pineal gland” located?
Brain
What hormone does the pineal gland secrete?
Melatonin
- regulates sleep cycle or the circadian rhythm
How many glands are located in the anterior neck “cervical regions”?
2
What are the 2 glands located in the anterior neck cervical regions?
- thyroid
- parathyroid
What does the “thyroid gland” primarily release?
- triiodothyronine (T3)
- thyroxine (T4)
Both T3 and T4 contain iodine which is bound to proteins in the blood via TBG (thyroxine-binding globulin). Both of these contain iodine which is important for iodine metabolism.
What does the “parathyroid gland” primarily release?
Parathyroid hormone (PTH)
- located posterior to the thyroid gland
What does the ‘parathyroid hormone’ do?
Helps with calcium metabolism by increasing blood calcium levels
- when released it increases calcium levels in the blood by pulling the calcium from the bones and putting it directly into the bloodstream
True or False:
These glands are not palpable even if they’re enlarged. These are paired glands. Viewing these glands in ultrasound or an MRI you would expect to see the same number on the right and the left and most people have 4-6 glands.
True
What do the thyroid and parathyroid work together to do?
- regulate calcitonin
- calcium metabolism
In the “thorax region”, what gland is present?
Thymus
- at the top of the heart right behind the breastbone
What hormone does the ‘thymus gland’ secrete?
Thymosin
- has more of an immune system function than anything else
In the “epigastric region”, what gland is present?
Pancreas
- posterior to the stomach
What 2 hormones do the ‘pancreas’ secrete?
- Glucagon
- Insulin
What does ‘glucagon’ and ‘insulin’ do for the body?
Regulate glucose metabolism in the body
In the “lumbar region” in the retroperitoneal cavity, what glands is present?
Adrenal glands
- on top of the kidneys
What do the ‘adrenal glands’ secrete?
- Cortisol
- Aldosterone
- Norepinephrine
- Epinephrine
- adrenal glands are typically secreted during a stressful situation (fight or flight response)
In the female reproductive system, located in the right and left inguinal regions are the ‘ovaries’. What do they produce?
- estrogen
- progesterone
In the male reproductive system, located in the scrotum, are testes which produce?
Testosterone
The outer cortex secretes 3 hormones called …
- Cortisol
- Aldosterone
- Testosterone
What does ‘cortisol’ do?
- Decreases inflammation
- Increases fats and carbohydrates in the blood
What does ‘aldosterone’ do?
Responsible for water and sodium conservation
- helps the kidneys conserve sodium and eliminate potassium
The cardiovascular system runs on a sodium-potassium pump, so a lot of times if the kidneys or adrenal glands are malfunctioning, that may have a direct real relationship to the heart.
What does ‘testosterone’ do?
Responsible for the development of secondary male sex characteristics such as muscle hypertrophy, voice deepening, gonads development, sperm production, and an increase in hair in the face/neck, the axillary region, the inguinal region, and other parts of the body
The inner medulla secretes 2 hormones called …
- epinephrine
- norepinephrine
What does ‘epinephrine’ do?
Hormone that during a stressful situation, increases your blood pressure, increases your heart rate, and increases your respiratory rate
- Helps to pull blood from the inside of the body, and it pulls that blood towards your skeletal muscles
- rush of adrenaline
What does ‘norepinephrine’ do?
Increases the stress response and can be produced by exercise, adequate sleep, and higher protein diets (beans, bananas, oatmeal, fish, and red meat)
- exercise is good for stress
Hormone levels in the blood can signal that homeostasis is disrupted.
Since hormones signal a specific endocrine gland to release that hormone, there could also be a problem with the gland.
Hormones also act on target tissue to affect growth, metabolism, behavior, and reproduction.