Endocrine system full review

Adenohypophysis

Hypothalamus - anterior pituitary

Neurohypophysis

Hypothalamus - posterior pituitary

Autocrine messengers…

self secrete, and act on the cell that secretes the substance

Paracrine messengers…

secrete substances that act on nearby cells

Hormones…

release substances into the blood stream to act far away from their secretion site

Peptide hormones

made of amino acids

hydrophillic

travel freely in blood

fast effects but rapidly degrade

Steroid hormones

Made of cholesterol

hydrophobic

need a protein carrier

slow to take effect but long-lasting

Peptide hormones bond to ________ receptors because….

extracellular (outside of cell), they are hydrophilic, and cannot diffuse through the cell membrane.

Steroid hormones bind to _________ receptors because….

Intracellular (inside of cell), they are hydrophobic, and can diffuse past the cell membrane.

Monoanime hormones

exibit properties of both peptide or steroid hormones.

Up-regulation

Cells create more hormone receptors in response to a reduced hormone concentration in the blood

Down-regulation

Cells create less hormone receptors in response to elevated hormone concentration in the blood

Synergist hormones

hormones that work together to produce a greater effect

Permissive hormones

a first hormone allows the action of a second hormone

Antagonist hormones

one hormone causes the opposite effect of another hormone.

Neurones transmit signals from the hypothalamus directly to the __________

posterior pituitary (neurohypophysis)

Oxytocin (OT) and Antidiuretic hormone (ADH) are stored and released by…

The neurohypophysis

Oxytocin function

uterine contraction

promotes lactation

sexual hormone

Antidiuretic hormone function (ADH)

decrease urine production

stimulate thirst

constrict blood vessels

Hypothalamo-hypophyseal portal system of blood vessels carry….

releasing hormones from the hypothalamus to the anterior pituitary (adenohypophysis)

GH and IGF1 are…

effector hormones

GH and IGF1 function

increases blood glucose

muscle growth

bone elongation at epiphyseal plates

GH deficiency (pituitary dwarfism)

inadequate GH production. short stature and low blood sugar

Pituitary gigantism

too much GH. excessive growth.

Acromegaly

excessive GH in adults. enlargement of bones or face, hands and feet.

Follicular cells

produce and release TH hormone (thyroid).

cuboidal epithelial cells that surround a central lumen

Parafollicular cells

cells around follicular cells that make calcitonin

decreases blood calcium levels

Thyroid hormone effects

regulates the body’s metabolism, energy usage, and ensure organs work correctly

Hyperthyroidism (Graves disease)

excessive TH in the body. increased metabolic rate, weight loss, and heat intolerance.

Hypothyroidism

decreased TH in the body. Low metabolic rate, weight gain, cold intolerance and weight gain. caused by decreased iodine intake.

Goiter

enlargement of the thyroid due to insufficient iodine intake in diet.

Cortisol hormone function

regulates the body’s stress

Cortisol is released by the

Zona fasiculata of the adrenal gland

Hypocorticisteroidism

low levels of cortisol secretion.

causes low blood sugar, low glucose, anxiety and fatigue.

Hypercorticosteroidism (cushings disease)

high levels of cortisol secretion.

causes immune suppression, high glucose, blood pressure

and redistribution/accumulation of fat.

Adrenogenital syndrome

High ACTH levels masculinize newborn babies.

adrenocorticotropic hormone stimulates the adrenal glands to produce..

cortisol

Prolactin is secreted by the

mammary glands

milk production

The pancreas releases

insulin

Aldosterone is secreted by…

The zona glomerulosa of the adrenal cortex

Androgens are secreted by the

zona reticularis of the adrenal cortex

The Gonadotropin pathway is an _________ pathway

adenophypophysis

Melatonin _____ go through the hypothalamus

does not

Melatonin is secreted by _________ at night

the pineal gland

Parathyroid glands

small structures on the back of the thyroid gland

Parathyroid function

increases blood calcium by stimulating osteoclasts

Thymic hormones

maturation site for T-lymphocyte white blood cells

Atrial natriueric peptide

lowers blood pressure

erythropoietin

causes increased red blood cell production

angiotensinogen

helps raise blood pressure when its about to fall

Gastrin

increases secretion and mobility in stomach for digestion

Humoral stimulation

stimulates blood/ion nutrients level

the adrenal medulla produces

nor/epinephrine