Chapter 13- Endocrine System

Paracrine

Secrete near

endocrine glands

ductless cells, tissues , and organs that secrete hormones through the bloodstream to a target cell

exocrine glands

glands that secrete into ducts or tubes that lead outside the body

Hormones

biochemical messengers secreted by endocrine glands through the bloodstream to a target cell

major endocrine glands

hypothalamus

pituitary

thyroid

adrenal

pancreas

Hormones exert effects by altering ______ ________ like enzyme activity and rate of membrane transport

metabolic processes

steroid hormones have ___ water solubility

poor

steroid hormones ___ diffuse through the lipid bilayer

can

steroid hormones are produced from:

cholesterol

steroid hormones include:

sex hormones

adrenal cortex hormones

non steroid hormones _____ penetrate the lipid bilayer

cannot

first non-steroid hormone messenger

hormone

second non-steroid hormone messenger

chemical

non steroid hormones include:

amines, proteins, peptides, glycoproteins

what are most hormones ?

non-steroid hormones

amines

derived from tyrosine

proteins

long chains of amino acids

peptides

short chains of amino acids

glycoproteins

carbohydrates joined to proteins

upregulation

increase in # of receptors on target cell in response to a decrease in hormone level

downregulation

decrease in # of receptors on a target cell due to an increase in hormone level

hormone secretion is mainly controlled by

negative feedback mechanisms

how long do effects from hormone secretion last

from a few minutes to a few days

how are hormones excreted

urine

hormones can be broken down by enzymes, primarily from the _____ to stop their effects

liver

tropic hormones

hormones that act on other glands to regulate their hormone secretion

the nervous system controls hormone secretions by

stimulating some glands to secrete their hormones

how does changing internal environment effect hormone secretions

changing substance levels in the blood stimulates the secretion of hormones

steroid abuse

increase muscle strength

steroid side effects

decreasing natural testosterone, stunting growth, breast development in males, male sexual characteristics in females kidney , liver , and heart damage, increased cholesterol, psychiatric problems

growth hormone abuse

enlarges muscles

eryhthropoietin abuse

increases number of blood cells and oxygen in muscles

erythropoietin side effects

can lead to heart attack and death

hypopituitary dwarfism

deficiency in GH during childhood leading to short stature but normal proportions and mental development

gigantism

oversecretion of GH during childhood leading to increased height often caused by a pituitary tumor

acromegaly

oversecretion of GH as an adult after epiphyseal ossification leading to thickened bones

How does the hypothalamus control hormones from peripheral endocrine glands

it releases hormones that act on specific hormone secreting cells in the APG. The APG hormone then stimulates cells in a peripheral endocrine gland to stimulate secretion

Pituitary Gland

major endocrine at base of the brain attached to and controlled by the hypothalamus by the pituitary stalk

The anterior lobe of the pituitary gland is made of:

glandular epithelium

How is the anterior lobe of the pituitary gland regulated?

The hypothalamus releases hormones through the Hypophyseal Portal System to stimulate the anterior lobe to release hormones

which lobe produces the growth hormone

anterior

growth hormone

makes cells grow and divide quickly

what doess growth hormone increase?

amino acid, protein, and lipid produc

what does growth hormone decrease?

carbohydrate usage

Prolactin (PRL)

promotes lactation

Thyroid stimilating hormone

stimulates thyroid

Follicle Stimulating Hormones (FSH)

Growth and development of ovarian follicles in females, sperm production in males

Lutenizing Hormones (LH)

Ovulation in females, sex hormone production in males

Adrenocorticotropic Hormone (ACTH)

cortisol sectrion from adrenal cortex

which lobe produces prolactin

anterior

which lobe produces thyroid stimulating hormone

anterior

which lobe produces follicle stimulating hormone

anterior

which lobe produces lutenizing hormone

anterior

which lobe produces adrenocorticotropic hormone

anterior

the posterior lobe of the pituitary gland is made of

nerve fibers

how is the posterior lobe of the pituitary gland regulated

nerve impulses from hypothalamus travel through the infundilum and stimulates nerve endings to release hormones

which lobe produces the antidiuretic hormone

posterior

antidiuretic hormone (ADH)

decreases urine production and causes vasoconstriction to increase blood pressure

oxytocin

muscle contraction during childbirth and with ejection during lactation

What is the thyroid gland

an endocrine gland with two lobes connected by an isthmus located just below the larynx

the thyroid gland removes _____ from the blood

iodine

the thyroid gland is made of

follicles each surrounded by one layer of follicular cells. Colloid fills follicle cavities

T4 (Thyrosine) increases

carbohydrate energy and protein synthesis

T4 (thyrosine) accelerates

growth

T4 (thyrosine) stimulates

nervous system activity

T3 (triiodothyronine) has the same effects as ______ but is 5x more potent

T4 (thyrosine)

Calcitonin

lowers blood calcium and phosphate ions

T4 is secreted by the

thyroid

T3 is secreted by the

thyroid

Calcitonin is secreted by the

thyroid

Hyperthyroidism causes:

high metabolism

heat sensitivity

restlessness

hyperactivity

weight loss

goiters

Graves disease

overstimulation of thyroid from autoantibodies binding to TSH receptors

Hashimoto

autoantibodies destroy thyroid cells

Infantile Hypothyroidism causes:

stunted growth

abnormal bone formation

intellectual disability

Adult Hypothyroidism causes:

low metabolic rate

cold sensitivity

poor appetite

swollen tissues

Parathyroid glands

4 glands located on posterior surface of thyroid glands that secrete parathyroid hormone

How does the parathyroid hormone work

it increases level of blood Ca+2 and decreases level of blood PO4-2 by acting on bones, kidneys, and intestines

The parathyroid hormone acts on kidneys to cause final step of _____ _ ______ which indirectly stimulates absorption of ___

Vitamin D Production

Ca+2

Adrenal Glands

Endocrine glands that sit on top of each kidney

Adrenal Cortex

Outer portion of adrenal glands

Adrenal Medulla

central portion of adrenal glands

Where is epinephrine secreted from

Adrenal medulla

Epinephrine increases:

heart rate

metabolic rate

force of contractions

vasodilation

cardiac output

Epinephrine causes airway

dilation

epinephrine activates _____ _____ of brainstem

reticular formation

epinephrine promotes breakdown of _____ __ _____ increasing blood sugar

glycogen to glucose

Norepinephrine is secreted by the

adrenal medulla

Norepinephrine increases

heart rate

metabolic rate

force of contractions

vasoconstriction

Aldosterone is secreted by the

adrenal cortex

aldosterone

regulates concentration of extracellular electrolytes through the sodium-potassium pump

Cortisol is secreted by the

adrenal cortex

Cortisol decreases

protein synthesis

Cortisol increases

fatty acid release

Cortisol stimulates

glucose synthesis from non carbohydrates

Adrenal androgens are secreted from the

adrenal cortex

Adrenal angrogens

supplements sex hormones from gonads

Adrenal androgens may be converted into

estrogens

zona glomerulosa

outer zone of adrenal cortex that produces aldosterone

zona fasciculata

middle zone of adrenal cortex that produces cortisol

zona reticularis

inner zone of adrenal cortex that produces male sex hormones