Kaplan Biology 5: Endocrine System

what does endocrine system consist of

glands that secrete hormones

what are hormones

signaling molecules that are secreted in bloodstream

• bind to receptor and induce change

what are the 3 types of hormones

• peptide

• amino acid derivative

• steroid

describe peptide hormones

• peptide chain cut off from larger proteins

  • created in endoplasmic reticulum

  • modified in golgi apparatus

• polar

  • cannot pass through membrane

  • must use receptor on membrane

• travels freely in bloodstream

describe the mechanism in which peptide hormones use

• first messenger

  • hormone that binds to receptor

• secondary messenger

  • molecule that is activated by the first messenger inside the cell

describe steroid amino acid

• hormones derived from cholesterol

  • can easily cross membrane

  • bind to intracellular receptor

  • creation of hormone-receptor complex

  • receptor binds directly to DNA

• Nonpolar

  • must be carried by proteins in the bloodstream

Describe the G-protein coupled receptor mechanism as it pertains to adenylate cyclase

• hormone binds to receptor

• receptor activates adenylate cyclase

• cAMP levels increase

• cAMP binds to protein kinase

• protein kinase phosphorylates transcription factors

Describe direct hormones

• secreted and directly act on target organs

  • insulin directly causes glucose uptake

describe tropic hormones (indirect)

• hormones that require intermediate to act

  • GnRH requires LH and FSH for estrogen and testosterone production in gonads

• usually originate in brain

Describe all the endocrine organs (9)

• in the brain

  • hypothalamus

  • pineal gland

  • pituitary gland (anterior and posterior)

• in the throat

  • thyroid gland

  • parathyroid gland

• under the chest

  • pancreas

  • adrenal gland

• gonads

  • testes

  • ovaries

describe the hypothalamus

regulates and interacts with the pituitary gland

describe how the hypothalamus interacts with the anterior gland

• hypophyseal portal system

  • blood vesicles

describe how hypothalamus interacts with posterior gland

using axons in pituitary stalk

describe the hormones released by the posterior pituitary gland via the pituitary gland

• oxytocin

• antidiuretic hormone

describe oxytocin hormone and where it is found

• responsible for

  • activating muscles required for lactation

• found in

  • posterior pituitary gland

describe antidiuretic hormone (ADH) and where it is found

• responsible for

  • increased water reabsorption that raised blood volume and pressure

• found in

  • posterior pituitary gland

Describe the GnRH protein from hypothalamus and anterior pituitary gland response

• hypothalamus

  • GnRH

• anterior posterior gland

  • LH

  • FSH

What type of hormone is LH and FSH

“FLAT PEG”

• tropic hormones

Describe corticotropin releasing factor (CHF) from hypothalamus and response from anterior pituitary gland

• hypothalamus

  • corticotropin releasing factor

• anterior pituitary gland

  • adrenocorticotropic hormone (ACTH)

describe adrenocorticotropic hormone

• found in

  • anterior pituitary gland

• tropic hormone

  • acts on adrenal cortex

    • releases cortisol

describe thyroid stimulating hormone from hypothalamus and the anterior pituitary gland response

• hypothalamus

  • thyroid-releasing hormone (TRH)

• anterior pituitary gland

  • thyroid-stimulating hormone (TSH)

describe thyroid-stimulating hormone

• found in

  • anterior pituitary gland

• tropic hormone

  • acts on thyroid

    • stabilized metabolic rate

    • calcium homeostasis

describe cortisol

• fight or flight hormone released during stress

• increases glucose in blood

  • gluconeogenesis

describe the growth-releasing hormone and its response to anterior pituitary gland-

• hypothalamus

  • growth hormone releasing hormone (GHRH)

• anterior pituitary gland

  • growth hormone

describe the growth hormone

• direct hormone

  • works directly on bone and muscle

• responsible for

  • growth of bone and muscle

• found in

  • anterior pituitary gland

describe endorphins

• responsible for

  • pain relief

• found in

  • anterior pituitary gland

• direct hormone

  • works directly on organs

describe prolactin-inhibiting factor released from hypothalamus and response from anterior pituitary gland

• hypothalamus

  • prolactin inhibiting factor

• anterior posterior gland

  • inhibits prolactin

describe prolactin inhibiting factor

• inhibits prolactin

• prolactin

  • responsible for milk production

describe prolactin

• stimulates milk production

  • stimulates mammary glands

• increases when

  • placenta drops

  • estrogen and progesterone levels drop

Describe the mnemonic for direct and tropic hormones in the anterior pituitary gland

“FLAT PEG”

• tropic

  • FSH

  • LH

  • Adrenocorticotropic hormone

  • thyroid-stimulating hormone

• direct

  • prolactin

  • endorphin

  • growth-stimulating hormone

how does milk ejection work

• nipple stimulation activates hypothalamus

  • oxytocin is released

    • from posterior pituitary gland

    • contracts smooth muscle of breast

  • prolactin is released

    • stimulates milk production

describe the antidiuretic hormone

• secreted from

  • posterior pituitary gland

• responsible for

  • increasing blood volume

  • increases water reabsorption

describe oxytocin

• secreted from

  • posterior pituitary gland

• responsible for

  • contracting breast uterine smooth muscle

describe how the thyroid gland works

• stabilizes basal metabolic rate

  • releases T3 and T4

• calcium homeostasis

  • C-cells in thyroid produce calcitonin

Describe T3 and T4

• tyrosine amino acid that’s iodized

  • T3 has 3 iodine atoms attached

  • T4 has 4 iodine atoms attaches

• produced by follicular cells

Describe calcitonin

• produced by C-cells

  • regulates calcium levels

  • decreases blood calcium concentration

Describe hormone produced by parathyroid gland

parathyroid hormone (PTH)

Describe parathyroid hormone (PTH)

• works against calcitonin

• raises calcium blood levels

Describe the 2 parts of the adrenal gland

• adrenal cortex

• adrenal medulla

Describe the 3 hormones found in the adrenal cortex

• glucocorticoid

• mineralocorticoid

• cortical sex hormone

describe glucocorticoid

• steroid hormones that regulate glucose hormones

  • increase glucose levels via gluconeogenesis

• example

  • cortisol

  • cortisone

• produced from

  • adrenal cortex from adrenal gland

describe mineralocorticoid

• hormones that increase sodium reabsorption

  • water follows salt into blood and increases blood volume and pressure

• example

  • aldosterone

• produced from

  • adrenal cortex from adrenal gland

describe cortical sex hormones

• produced from

  • adrenal cortex from adrenal gland

• example

  • androgens

  • estrogen

  • testosterone

describe hormones produced by adrenal medulla

• responsible for fight or flight hormones

  • increase glucose concentrations

    • vasoconstriction

      • decreased blood flow to gut, kidneys, skin

    • vasodilation

      • increased blood to heart, muscle, lungs, brain

• example

  • epinephrine

what are type of sympathetic hormones

• epinephrine

• cortisol

Describe the types of cells in the pancreas

• alpha

  • glucagon

• beta

  • insulin

• delta

  • somatostatin

describe alpha cells from pancreas

• release glucagon

  • hormone that raises blood sugar levels

  • used to treat low blood sugar

describe beta cells from pancrease

• release insulin

  • hormone that lowers blood sugar levels

  • induces increased uptake of glucose

describe diabetes

• type 1

  • autoimmune system attacks B-cells in pancreas

    • genetic

• type 2

  • development of insulin resistance

    • bad lifestyle

Describe the hormone produced in the pineal gland

melatonin

ADH

Antidiuretic hormone

FSH

Follicle stimulating hormone

LH

Luteinizing hormone

ACTH

Adrenocorticotropic hormone

TSH

Thyroid stimulating hormone

PTH

Parathyroid hormone