AP Biology Endocrine System (Gland & Hormones)

Gland:

Function:

Hormones:

Location:

Thyroid

1. regulate the body’s metabolism

2. regulates growth and development

-thyroxin: controls the rate at which your body metabolizes glucose

-triiodothyronine: similar to thyroxin but more potent; used in the treatment of hypothyroidism (abnormally low activity of thyroid gland, resulting in retardation of growth and mental development

-lower, front part of neck

Parathyroid

control the body’s calcium levels

-parathyroid hormone (PTH): raises blood calcium levels

-two pairs of small glands embedded in the surface of the thyroid gland

Hypothalamus

1. initiates an endocrine response receives from NS

-releasing hormones: stimulates the pituitary gland to release hormones (CRH, GHRH, TRH, PRH)

-inhibiting hormones: inhibits the release of hormones in the pituitary (dopamine inhibits the release of prolactin)

-below the thalamus, just above the brain stem 

Pituitary

-“master gland”

1. regulates bodily functions

Anterior Lobe

-growth hormone: hormone targeting bones and muscles to drive growth and development

-somatotropin: promote growth in children (HGH)

-thyroid-stimulating (TSH): stimulates thyroid to release hormones (thyroxine & Calitonin)

-adrenocorticotropin (ACTH): stimulates the adrenal gland (in the adrenal cortex) to release adrenal steroid hormones

-luteinizing hormone (LH): sexual development

-follicle-stimulating hormone (FSH): sexual development / stimulate follicular growth

-prolactin: milk production/secretion

Posterior Lobe

-antidiuretic hormone (vasopressin): promotes retention of water by the kidneys (osmoregulation)

-oxytocin: regulates milk secretion by the mammary glands & stimulates contraction of the uterus

-base of the brain; below the hypothalamus

Adrenal

1. regulate metabolism and blood pressure in response to stress

Adrenal Cortex

-steroid hormones: bind to intracellular receptors to alter gene expressions

• cortisol: aka hydrocortisone; steroid hormone that regulates carbohydrate (i.e. glucose) metabolism and maintains blood pressure

• aldosterone: steroid hormone that regulates the salt and water balance in the body; causes kidneys to conserve sodium

Adrenal Medulla

-catecholamines: help the body cope with physical and emotional stress by increasing the heart rate and blood pressure; flight or fight response

• adrenaline: 

• noradrenaline: 

-two triangular-shaped glands located on top of each kidney

Pineal

1. regulate circadian rhythm

2. receive information about light and dark cycle

-melatonin: released in periods of darkness. Binds to receptors in the brain to reduce nerve function

-middle of the brain

Testis

-androgen: a male sex hormone that promotes the development and maintenance of the male sex characteristics; sperm production

• testosterone: regulate fertility

-in the scrotum

Ovaries

-estrogen: promotes development and maintenance of female secondary sex characteristics

-progesterone: supports pregnancy

-on both sides of the uterus

Pancreas

1. regulates blood sugar

2. produces enzymes to aid digestion

Exocrine Pancreas

-digestive hormones: essential for processing foods and digestion

Endocrine Pancreas

-insulin: decreases blood sugar

-glucagon: increases blood sugar

Briefly explain feedback btwn

-insulin & glucagon: work in a negative feedback loop to maintain stable blood sugar levels

-elongated organ located toward the back of the abdomen behind the stomach

Thymus

-produces lymphocytes

-aids in producing immunity

-atrophies with age

-thymosin: stimulate production of T Cells

-lies underneath the top of the breast bone; upper chest cavity