endcrine im crine sonion ok get into it

homeostasis

the tendency of the body to mainatin relatively constant internal envrionemtn regardless of a changing external environment

what is the endocrine system in charge of

controls the functions of the body through the usage of hormones which travel in the blood

route of hormones

1. hormone gets released from gland into ECF (extracellular fluid)

2. transported via the blood

3. hormone gets attatched to a specific part of the body

2 types of hormone

protein hormone

steroid hormone

protein hormone

• has a target organ

• does NOT enter the cell

• just attatches to the receptors of the cell which causes enzymes to be activated within the cell

• water soluble

example: insuline, growth hormone, adrenaline

steroid hormones

• can cross the cell membrane

• enter the NUCLEUS

• activate certain genes - attatch to CHROMATIN to send messages to the ribosomes to produce specific proteins

• fat soluble

examples: estrogen, testosterone, cortisol

endocrine glands

secrete hormones

exocrine glands

secretes hormones or substances

example: salivary glands, sweat glands

hormone vs nerve impulses

hormone action is much slower than nerve impulses because they have to circulate through the blood stream

the only hormone that is “immediate” is adrenaline (coz we need that to frikin survive baka)

2 types of hormones (based on activation site)

non target hormones

target hormones

non target hormones

affect many sites of the body instead of just one target site

target hormones

affect specific cells or body tissue

homeostasis systems operate on…

negative feedback loops: when you have to fix something, something gets stimulated to bring that something back to normal, but when it goes back to normal, the fixing agent gets stopped!

hypothalamus function

regulated the pituitary gland through nerve stimulation (through the brain) or through the release of hormones

the hypothalamus produces

tropic hormones which travel from the hypothalamus to the pituitary gland to release more hormones

what is a tropic hormone

a hormone that triggers the release of another one

GHRF

growth hormone releasing factor - the tropic hormone in charge of stimulating the pituitary gland to release growth hormone

PRH

prolactin releasing hormone - stimulates the pituitary gland to release prolactin

what are inhibiting hormones

hormones that stop the release of a specific hormone

what is the pituitary gland

it is the “master gland” and controls the other endocrine glands. it has both anterior and posterior lobes

posterior lobe

stores and releases ADH and Oxytocin

hormones are produced in the hypothalamus

where is ADH and oxytocin produced

in the hypothalamus

oxytocin

responsible for uterine contractions during childbirth

ADH (antidiuretic hormone)

acts on the kidneys to increase water reabsorption into the blood

anterior pituitary gland

produces its own hormone and transports it through the blood

hormones released by the anterior pituitary gland

TSH - thyroid stimulating gland

ACTH - adrenocorticotropic hormone

hGH - human growth hormone

TSH

thyroid stimulating hormone stimulates the thyroid to release thyroxine which regulates cell metabolism

ACTH

adrenocorticotropic hormone

stimulates the adrenal gland to produce cortisol

hGH

human growth hormone

promotes growth - usually more active during childhood

inhibited by somatostatin