Ch. 16: The Endocrine System

WHere do endocrine glands secrete their substance

ENDO: directly into the blood

where do exocrine glands secrete their stubstances

EXO: sercrete external secretions into body cavities or onto body surface via ducts (tears, sweat, saliva)

E.

what makes a cell the target of a hormone

target cells have receptors specific for each hormone

memorize ts on notability

what are three most comon types of amino acid based hormones

• proteins (insulin and glucagon)

• peptides (ADH and oxytocin)

• derivatives of amino acids (thyroid hormones)

what are the 4 steps of amino acid based hormones

1. bind to extracellular receptors

2. activate a 2nd messenger such as cAMP

3. cAMP activates kinase enzymes that turn on other enzymes

4. turns on existing proteins and what not

When insulin binds to receptors on its target cells, it quickly turns on glucose transporters. Glucose is taken into the target cells by ___ ___ ___ ___

carrier mediated facilitated diffusion

“Insulin lowers blood glucose levels” means that

_______________.

A. Insulin signals target cells to increase uptake of

glucose molecules from the blood

B. Insulin binds to glucose molecules and removes

them from the blood

C. Insulin transports glucose molecules into cells by

carrier-mediated facilitated diffusion

D. Insulin breaks down glucose molecules by

glycolysis

A. insulin signals target cells to increase uptake of glucose molecules from the blood

steroid hormones are ____ soluble derived from ___

lipid; cholesterol

steroid hormones are synthesized by two things…what are they

• gonads: testosterone, estrogen, progesterone

• adrenal cortex: aldosterone, cortisol, cortisone, etc.

why do steroid hormones and thyroid hormones bind to intracellular receptors

closer to DNA

explain the process of steroid and thyroid hormones

1. hormone forms a complex with the receptor and enters the nucleus

2. receptor hormone complex activates genes in the DNA

3. results in synthesis of new proteins

glucagon _____ blood sugar while insulin ____ levels

glucagon raises levels while insulin lowers levels

Gluvagon and insulin are secreted from Islets of Langerhans cells in the pancreas. Beta and alpha cells secrete what?

Alpha cells secrete gluvagon

beta cells secrete insulin

where would you predict the hormone receptors for insulin and glucagon be located on their target cells…why?

embedded on the cell membrane

Amino Acid hormones do not cross the cell membrane

this molecule is used to store glucose in the liver

glycogen

where is glycogen stored

liver

what is glycogenolysis in the liver

the release of free glucose into the blood to maintain normal blood glucose levels

what is the cause of type 1 diabetes

autoimmune disease. Body creates antibodies that attack the insulin producing beta cells in the pancreas

a person who has type 1 diabetes will not be able to…

produce insulin and is permanent

this type of diabetes…

• autoimmune response(bodys immune system attacks the insulin producing cells of the pancreas)

type 1

this type of diabetes…

• typically 90% of all cases of DM

• typically seen in overweight adults after the age of 40

• strong hereditary link

type 2

what is the cause of type 2

unable to secrete insulin or unable to effectively use insulin

which type of diabetes is this…

• abnormal or missing insulin receptors

• abnormal glucose transporters

• diet and exercise seen to help

• any abnormality that does not allow effective usage of insulin

type 2

what is hyperglycemia and what can cause hyperglycemia

• too much sugar

• cause: type ½ diabetes

what bony feature of the skull encloses and protects the pituitary gland

sella turcica

what are some characteristics of the POSTERIOR pituitary gland and what hormones would be secreted from here?

• neural tissue

• developed from a downward projection of the hypothalamus

• composed of axons and axon terminals

• oxytocin and ADH

what are some characteristics of the ANTERIOR pituitary gland

• developed from an UPWARD projection from the roof of the mouth

the hormones synthesized in the hypothalamus are transported to the posterior pituitary gland by the ___ ___ ___

hypothalamic-hypophyseal tract

what does ADH promote

water conservation by preventing diuresis (large loss of water in the urine)

What does a HYPOsecretion of ADH cause

diabetes insipidus; huge output of dilute urine and intense thirst (different from diabetes mellitus)

explain how adh and dehydration are related

• Dehydration stimulates the hypothalamus to produce antidiuretic hormone (ADH), which is released from the posterior pituitary gland. ADH then acts on the kidneys to increase water reabsorption back into the bloodstream, helping restore fluid balance and reduce dehydration.

how can a head injury cause diabetes insipidus

• head injury may damage the hypothalamic neurons that synthesize ADH or posterior pituitary that secretes ADH

OXYTOCIN and ADH are neurohormones, synthesized by the ____, transported in the ___-___ ___, and is secreted from axon terminals in the ___ ___

synthesized by the hypothalamus; transported in the hypothalamic-hypophyseal tract; secreted from axon terminals in the posterior pituitary

what hormones are secreted by the anterior pituitary gland

GH

PRL

FSH

LH

TSH

ACTH

what 4 hormones secreted by the Anterior pituitary gland are tropic hormones, what does tropic mean

1. FSH (follicle stimulating hormone)

2. LH (luteinizing hormone

3. TSH (thyroid stimulating hormone)

4. ACTH (adrenocorticotropic hormone)

• tropic: a hormone that targets and stimulates other endocrine glands to grow and secrete their own hormones

how do the hormones secreting in th hypothalamus get tp the anterior pituitary gland

hypothalamic hormones travel in blood vessles leading to the anterior pituitary

what hormones secreted by the anterior pituitary gland are NOT tropic hormones

Growth hormone and prolactin

what does the mnemonic device GPA refer to

G: Growth Hormone

P: Prolactin

A: acidophils

• growth hormone and prolactin are produced and secreted by acidophils (they also stain well with acid dyes)

GH secretion is controlled by which two hypothalamic neurohormones

1. GHRH

2. GHIH

what are direct effects of GH

METABOLISM

• makes fuels such as fatty acids and glucose more available for cellular growth

How does GH promote indirect growth

IGF (insulin like growth factor) stimulate body cells to enlarge and divide

long bones grow to adult size by ____ ____

endochondral ossification

Hypersecretion of GH is often caused by an anterior pituitary tumor. What does hypersecretion of GH cause?

CHILDREN

• Gigantism: excessive lengthening of long bones; extreme height (8 feet or more)

ADULTS

• Acromegaly: bones in the face and feet, hands continue to grow.

Hyposecretion of GH causes what?

CHIlDREN

• pituitary dwarfim: abnormally short height (2-4ft) but fairly normal body proportions

ADULTS

• rare, fat mass and decrease in muscle mass, decreased energy and quality of life

what is the function of prolactin

Prolactin is a peptide hormone, primarily produced by the pituitary gland, essential for initiating and maintaining lactation, developing breast tissue, and regulating reproductive functions

why is the anterior pituitary not a master gland

it is under the influence of the hypothalamus, so the hypothalamus should be considered the master gland

what does the mneumonic device BFLAT stand for

Basophils produce and secrete FSH, LH, ACTH, TSH

the tropic hormones are… and they are secreted by…

TSH, ACTH, FSH, LH

secreted by basophils

what teo hormone secreted by the anterior pituitary gand are gonadotropins

• FSH and LH

What hormones are considered to be gonadotropins and what is their function

• FSH and LH

• target the ovaries and testes

• cause secretion of the steroid sex hormones and development of sex cells

this gland…

• H-shaped butterfly located in the anterior aspect of the neck

thyroid gland

In the thyroid gland has lobes which are composed of hollow spherical follicles. What do these