Chapter 17: Endocrine System

endocrine system

Which body system helps regulate the functioning of the other body systems?

endocrine system

Which body system has the following functions:

• Reproduction

• Growth & development

• Blood levels of electrolytes, H₂O & and nutrients

• Metabolism & energy

• Mobilizing defenses

endocrine system

What body system has...

• Slower (lag time)

• Longer response duration

• Diffuses to the bloodstream

• Long distance

ductless glands

Also known as endocrine glands, they are the glands that release secretions called hormones directly into the bloodstream

hormones, autocrines, paracrines

What are the three chemical messengers of the endocrine system?

hormones

Which chemical messenger, manufactured by the endocrine glands, travels through the bloodstream, and affects other tissues?

hormones

Which chemical messenger(s) travel long distances?

autocrines and paracrines

Which chemical messenger(s) travel short distances?

autocrines

Which endocrine cells release a substance and bind to the receptor on the SAME cells?

paracrines

Which endocrine cells release a substance and bind to the receptor on similar tissue on DIFFERENT cells?

monoamines/biogenic amines, steroids, proteins/(poly)peptides, eicosanoids

What are the chemical classifications of hormones?

monoamines or biogenic amines

What type of hormone is H₂O soluble (except for thyroid hormones) and soluble in blood?

ex.) epinephrine and norepinephrine

thyroid hormones

What is a biogenic amine that is insoluble in water and requires a carrier protein?

epinephrine and norepinephrine

What hormones are also considered neurotransmitters?

proteins/(poly)peptides

What type of hormone is H₂O and blood soluble?

ex.) antidiuretic hormone

steroids

What type of hormone is lipid-soluble and requires carrier proteins in the blood?

ex.) testosterone

steroids

What are the following hormones classified as? They are not water-soluble and require a carrier protein.

cortisol

aldosterone

estrogens

progesterone

testosterone

eicosanoids

What type of hormone is considered "local"?

ex.) prostaglandins, leukotrienes, thromboxanes

prostaglandins

What type of eicosanoid causes the following:

Blood pressure

Uterine contractions

Blood clotting

Fever

Pain

Inflammation

leukotrienes

What type of eicosanoid causes the following:

inflammation

thromboxanes

What type of eicosanoid causes the following:

blood clotting

hormonal, humoral, neural

What are the 3 types of stimuli for hormone release?

humoral stimulation

Classify the stimulus for releasing hormones:

release of a hormone in response to changes in level of nutrient or ion in the blood

humoral stimulation

Classify the stimulus for releasing hormones by the example:

blood Ca²⁺ levels dip and the parathyroid hormone activates

neural stimulation

Classify the stimulus for releasing hormones:

the nervous system stimulates hormone release

neural stimulation

Classify the stimulus for releasing hormones by the example:

sympathetic nervous system & adrenal medulla receives action potentials

hormonal stimulation

Classify the stimulus for releasing hormones:

release of a hormone in response to another hormone

hormonal stimulation

Classify the stimulus for releasing hormones by the example:

releasing hormones from the hypothalamus, acting upon the thyroid gland

# of receptors a hormone has to a target, blood levels of hormone, binding affinity

What determines how a target cell will respond to a hormone?

plasma membrane

If a receptor is H₂O-soluble, it would be located in the...

intracellular

If a receptor is H₂O-insoluble, it would be...

up regulation

What type of regulation is used when receptors are added?

i.e.) someone is low in insulin and needs more

down regulation

What type of regulation is used when receptors are removed?

i.e.) too much insulin in the blood & needs to be cut down

permissiveness, synergism, antagonism

What are the 3 types of hormone interaction?

permissiveness

Define the hormone interaction:

one hormone cannot exert its effects without another hormone being present

permissiveness

Define the hormone interaction based on the example:

The presence of thyroid hormones doesn't affect reproductive hormones in development

synergism

Define the hormone interaction:

effects of 2 or more hormones amplify each other

synergism

Define the hormone interaction based on the example:

Glucagon & epinephrine work together to increase blood glucose levels

antagonism

Define the hormone interaction:

effects of multiple hormones oppose each other

antagonism

Define the hormone interaction based on the example:

Insulin & glucagon work against each other on blood sugar levels

anterior pituitary

What part of the pituitary gland produces and releases hormones?

anterior pituitary

What is the term also known as the adenohypophysis?

anterior pituitary

What part of the pituitary gland consists of glandular tissue?

posterior pituitary

What part of the pituitary gland deals with hormone storage and release, but NOT production?

posterior pituitary

What is the term also known as the neurohypophysis?

posterior pituitary

What part of the pituitary gland consists of neural tissue?

oxytocin (OT) and antidiuretic hormone (ADH)

In terms of neurohypophysis, which hormones are released by the hypothalamus?

oxytocin (OT) and antidiuretic hormone (ADH)

In terms of neurohypophysis, which hormones are stored in the posterior pituitary gland?

oxytocin (OT)

Define the posterior pituitary hormone:

target orgran(s): uterus & mammary glands

actions

• uterine contractions

• milk ejection

• sexual bonding ("cuddle hormone")

oxytocin (OT)

What hormone uses the phospholipase-C 2nd messenger system to induce contractions of the uterus?

antidiuretic hormone (ADH)

Define the posterior pituitary hormone:

target orgran(s):

• kidney tubules

• muscle walls of arterioles

• sweat glands

actions

• ↑ H₂O reabsorption →↓urine output & ↑BP (adds H₂O into blood, decreases urine output, and increases blood pressure)

• Vasoconstriction →↑BP

• ↓Perspiration (inhibits sweat glands to retain H₂O)

hypothalamic-hypophyseal tract

What are the nerve bundles that run through the infundibulum and connect the hypothalamus to the posterior pituitary gland?

hypothalamic-hypophyseal portal system

What connects the blood from the capillary bed in the hypothalamus that flows through the portal vein into the anterior pituitary gland?

infudibulum

The primary plexus of the hypothalamic-hypophyseal portal system is located in the...

anterior pituitary

The secondary plexus of the hypothalamic-hypophyseal portal system is located in the...

5 releasing hormones and 2 inhibiting hormones

In terms of the adenohypophysis, which hormones are involved?

anterior pituitary

What is the master endocrine gland?

tropins

What are the hormones that regulate the secretory action of other endocrine glands?

Growth hormone-releasing hormone (GHRH)

Thyrotropin-releasing hormone (TRH)

Corticotropin-releasing hormone (CRH)

Prolactin-releasing hormone (PRH)

Gonadotropin-releasing hormone (GnRH)

What are the hypothalamic releasing hormones?

Growth hormone-inhibiting hormone (GHIH) (aka somatostatin)

Prolactin-inhibiting hormone (PIH)

What are the hypothalamic inhibiting hormones?

Growth hormone (GH)

Prolactin (PRL)

Thyroid-stimulating hormone (TSH)

Follicle-stimulating hormone (FSH

Luteinizing hormone (LH)

Adrenocorticotropic hormone (ACTH)

What are the peptide/protein hormones?

Thyroid-stimulating hormone (TSH)

Follicle-stimulating hormone (FSH

Luteinizing hormone (LH)

Adrenocorticotropic hormone (ACTH)

What are the tropins in the anterior pituitary system?

growth hormone (GH)

What anterior pituitary hormone has the following direct actions?

• breaks down lipids

• increase blood glucose levels

• decrease glucose metabolism

• increase amino acid cellular uptake

growth hormone (GH)

What anterior pituitary hormone has the following indirect actions?

• increase nutrient uptake

• increase collagen & bone deposition

• increase bone & muscle growth

growth hormone-releasing hormone (GHRH)

What hormone from the hypothalamus increases growth hormone (GH)?

growth hormone-inhibiting hormone (GHIH) (aka somatostatin)

What hormone from the hypothalamus decreases growth hormone (GH)?

gigantism

Define the diagnosis:

Too much growth hormone WHILE the epiphyseal plate is active

Symptoms:

• increased longitudinal bone growth → extreme height

acromegaly

Define the diagnosis:

Too much growth hormone AFTER epiphyseal line forms, so other areas of hyaline cartilage still actively form bone

Symptoms:

• enlarged hands, feet, face, jaw

thyroid-stimulating hormone (TSH)

What anterior pituitary hormone has the following criteria?

Target organ: thyroid gland

Actions:

• thyroid development

- metabolism

- cell growth

- cell differentiation

thyrotropin-releasing hormone (TRH)

What hormone increases thyroid stimulating hormone (TSH)?

adrenocorticotropic hormone (ACTH)

What anterior pituitary hormone has the following criteria?

Target organ: adrenal cortex

Actions:

• increase cortisol levels for stress response

• increase gonadocorticoid levels

corticotropin-releasing hormone (CRH)

What hormone increases adrenocorticotropic hormone (ACTH)?

follicle-stimulating hormone (FSH)

What anterior pituitary hormone has the following criteria?

Target organ: testes & ovaries

Actions:

• ovarian follicle development

• increased estrogen

• sperm production

gonadotropin-releasing hormone (GnRH)

What hormone increases follicle stimulating hormone (FSH)?

gonadotropins

What are the hormones that stimulate the testes or ovaries?

luteinizing hormone (LH)

What anterior pituitary hormone has the following criteria?

Target organs: testes & ovaries

Actions:

• ovulation

• corpus lutem development

• increased testosterone

gonadotropin-releasing hormone (GnRH)

What hormone increases luteinizing hormone (LH)?

prolactin (PRL)

What anterior pituitary hormone has the following criteria?

Target organs: mammary glands

Actions:

• milk productions

prolactin-releasing hormone (PRH)

What hormone increases prolactin (PRL)?

prolactin-inhibiting hormone (PIH)

What hormone decreases prolactin (PRL)?

thyroid

What is the largest pure endocrine gland?

follicular cells

What cells secrete thyroid hormones?

colloid

What serves as thyroid hormone storage?

lumen

What serves as colloid storage?

parafollicular cells

What cells secrete calcitonin?

thyroid hormones (TH)

Identify the hormone:

Consists of T₃ and T₄

Actions

• increases metabolic rate

• increases cell growth

• increased cell differentiation

• increased heat production

thyroxin-binding globulins (TBGs)

What are the carrier proteins for thyroid hormones?

iodine and tyrosine

What are required for thyroid hormone synthesis?

hypothyroidism

Define the diagnosis:

Decreased amount in thyroid hormones

Causes:

inadequate iodine; abnormal pituitary stimulation; thyroid gland destruction

Symptoms:

• Weight gain, lethargy, cold sensitive

• goiter & low T₃ and T₄ blood levels

hyperthyroidism

Define the diagnosis:

Increased amount in thyroid hormones

Causes:

Excess pituitary stimulation (tumor), thyroid hormones supplementation, loss of TH regulation

Symptoms:

• weight loss

• hyperactivity

• heat intolerance

• elevated T₃ and T₄ blood levels

• exophthalmos

Grave's disease

Define the diagnosis:

• an autoimmune disorder that is caused by hyperthyroidism and is characterized by goiter and/or exophthalmos

• antibodies mimic TSH

Symptoms: exophthalmos

calcitonin

Identify the hormone:

Target organ: bone

Action: lowers blood Ca²⁺ levels

• decrease osteoclast activity → decrease bone resorption (doesn’t get released into bloodstream)

• increase uptake of Ca²⁺ by bone

• increase Ca²⁺ secretion by kidneys

parathyroid hormone (PTH)

Identify the hormone:

Target organ: bone

Action: increases blood Ca²⁺ levels

• increase osteoclast activity → increase bone reabsorption (return to bloodstream)

• activation of vitamin D → increase Ca²⁺ intestinal absorption

mineralcorticoids, glucocorticoids, and gonadocorticoids

What are the adrenal cortex corticosteroids?

aldosterone, cortisol, testosterone precursors

What are some examples of adrenal cortex hormones?

aldosterone (ALD)

What adrenal cortex hormone is a mineralocorticoid?

aldosterone (ALD)

Identify the adrenal cortex hormone:

Target organ(s): kidneys

Actions:

• increased Na+ reabsorption

• increased K+ secretion

• renin-angiotensin-aldosterone system (RAAS)

- blood pressure regulation

- blood volume regulation

cortisol

What adrenal cortex hormone is a glucocorticoids?

cortisol

Identify the adrenal cortex hormone: stress hormone

Actions:

• increases nutrients (glucose, fatty acids, and amino acids) into the bloodstream

• gluconeogenesis

• lipolysis

testosterone precursors

What adrenal cortex hormone is a gonadocorticoids?