Unit 11: Endocrine System

What is the system?

1. Made up of glands that produce and secrete hormones,

chemical messengers

2. Regulation of growth, metabolism, sexual development

3. Responses to stress and injury

4. Maintains homeostasis

Glands are found in different areas of the body.BIG IDEA:

HORMONES are chemical MESSENGERS

that act on target cellsMajor Structures of the Endocrine System

Write a short description of where each gland is located.

Pineal

Pituitary

Pineal

Hypothalamus

Pituitary

Brain

Thyroid

Thyroid

Parathyroid

Throat

Thymus

Thymus Above heart

Adrenal

Adrenal Above kidneys

Pancreas

Pancreas Under stomach

Ovary

Ovary / Testes Lower abdomen / Groin

TesteEndocrine – secretions inside the body

Exocrine – secretions outside the body (sweat)

Saliva

Breast Milk

SweatControl of Hormones

Negative feedback system

When the levels go above or below a SET POINT, the

endocrine system secretes hormones to lower or raise the

level.

thermostat Think of it like the

of your house.Example of Negative Feedback

When glucose levels rise -

insulin released by pancreas

causes uptake by blood

When glucose levels fall -

glucagon released from liver,

raising blood sugarPositive Feedback System - contractions during labor

When contractions push

the baby against the

cervix, the brain

releases the hormone

oxytocin which

strengthens

contractions.Pituitary Gland

- located below brain, attached to the hypothalamusThe pituitary is often called the

“master gland” because it controls all

of the other glands.

hypothalamus Its actions are controlled by the

in the brain.Anterior Pituitary Hormones

Prolactin or PRL - PRL stimulates milk production from a woman's

breasts after childbirth

Thyrotropin-releasing hormone

What effect does dopamine have on milk production?Growth hormone or GH -

- GH stimulates growth in

childhood

- important for maintaining a

healthy body composition.

- also important for

maintaining muscle mass

and bone mass.

What does declining HGH mean for a person as they age?Myostatin inhibits muscle growth

Myostatin inhibitor drugs

are being developed to treat

muscle-wasting diseases like

muscular dystrophy in

humans.

Question: Is this a negative or positive feedback system (myostatin and growth

hormones)? Is there a disadvantage to growing muscles this quickly?Problems with growth hormones can result in dwarfism or gigantism

Achondroplasia is the most

common type of dwarfism.

“The Alton Giant”, Robert

Wadlow. Robert was 8’11”Adrenocorticotropin or ACTH - ACTH stimulates

by the adrenal glands.

production of cortisol Cortisol, a so-called "stress hormone," is vital to survival.

It helps maintain blood pressure and glucose levels.

Many diet aids claim that they block

cortisol levels. Cortisol from stress may

lead to fat deposits in the belly.Thyroid-stimulating hormone or TSH - TSH stimulates

the thyroid gland to make thyroid hormones, which, in turn,

control (regulate) the body's metabolism, energy, growth

and development, and nervous system activity.Luteinizing hormone or

LH - regulates

testosterone estrogen in men and

in women.

(gonadotropin)Follicle-stimulating hormone or FSH - FSH promotes sperm

production in men and stimulates the ovaries to release eggs (ovulate) in

women. LH and FSH work together to allow normal function of the

ovaries or testes. (gonadotropin)*What happens to sex

hormone production as

you age?Posterior Pituitary Hormones

Oxytocin - Oxytocin causes milk letdown in nursing

mothers and contractions during childbirth.Antidiuretic hormone or ADH - ADH, also called

vasopressin, is stored in the back part of the pituitary

gland and regulates water balance.

Too much urination can lead

to dehydration. When the

body is dehydrated, ADH

will cause the kidneys to

conserve water.Diuretics – increase urine production

Many common foods and drinks contain chemicals

that are diuretics (alcohol)

Midol relieves symptoms of bloating

because it contains a diuretic that will

make you urinate more

Active Ingredients: (in each caplet):

Acetaminophen (500 mg) (Pain Reliever), Caffeine

(60mg) (Diuretic, Stimulant), Pyrilamine Maleate (15

mg) (Diuretic)

Inactive Ingredients: Carnauba Wax, Croscarmellose Sodium, FD&C Blue 2,

Hypromellose, Magnesium Stearate, Microcrystalline Cellulose, Pregelatinized Starch,

Propylene Glycol, Shellac, Titanium Dioxide, TriacetinHormones in Action

Why do you feel

thirsty?

Is this positive or

negative feedback?Anterior

Pituitary Hormones

PosteriorTHYROID GLAND

The thyroid hormones

control your metabolism,

which is the body's ability

to break down food and

store it as energy and

release of energy

TED-Ed Video on the ThyroidTHYROID HORMONES

Thyroxine (T4) & Triiodothyronine (T3)

- both increase the rate at which cells

release energy from carbohydrates

Calcitonin – regulates the blood

concentration of calcium

BMR – basal metabolic rate : how many

calories the body must consume to

maintain life ( BMR Calculator )Goiter - enlargement of the thyroid

Most cases are caused

by an iodine deficiency.

Iodine is added to salt to

add this essential

element to food.Hyperthyroidism (Grave’s Disease)

The thyroid gland

makes too much

thyroid hormone.

- weight loss

- hand tremors

- irregular heart rate

- bulging eyes

- cold sensitivityHypothyroidism

Before and after treatment with thyroid hormone

The thyroid gland

makes too little

thyroid hormone.

- weight gain

- fatigue

- hair loss

- slow heart rateParathyroid Glands

Located behind the

thyroid, four tiny glands

Parathyroid Hormone

(PTH) - takes calcium

from the bones to make it

available in the bloodAdrenal Glands

Located at the top of the kidneys

Adrenal Cortex - outer Adrenal Medulla - inner area

area

Adrenal Glands produce adrenaline

(epinephrine)Epinephrine (Adrenalin)

secreted from the adrenal

medulla

– increased heart rate

- increased breathing rate

- “fight or flight”

- response to stress People with severe life threatening

allergies often carry injectorsAdrenal Cortex

Aldosterone – helps

kidneys conserve sodium

and excrete potassium,

maintaining blood

pressureAdrenal Cortex

glucose Cortisol – keeps blood

levels stable,

response to stress

Adrenal Sex Hormones -

androgens (male) and

estrogens (female)Adrenal Gland Disorders

Cushing’s Disease Hyperadrenocorticism

● Increased thirst and

urination

● Increased hunger

● Increased panting

● Pot-bellied abdomen

● Obesity

● Loss of hair

Cushing's syndrome happens when the

adrenal glands makes too much cortisol.This is Suki

In 2015, she was diagnosed with

Cushing’s Disease

One month later, she was

diagnosed with diabetes.

While her condition was managed

with medication, though she

became blind. RIP 10/2018

*Cushings occurs more frequently in

certain breeds, like pugs and dachsundsAddison’s disease

○ Hyposecretion of cortisol

○ Low blood pressure

○ Increased pigmentation

corticotropin

-releasing hormone

adrenocorticotropin

-releasing hormonePancreas

The pancreas is a large gland behind the stomach that helps

the body to maintain healthy blood sugar (glucose) levels.

Pancreas in cat dissectionGlucagon – stimulates the

liver to break down glycogen,

raises blood sugar

the uptake Insulin – decreases blood

sugar concentrations, affects

of glucose by cells

*Both hormones work together to

maintain a balance in the blood sugarDiabetes – results from an insulin deficiency, blood

sugar rises (hyperglycemia) and excess is excreted in the urine.

Type I - juvenile onset diabetes,

often caused by immune disorder

that destroys pancreatic cells

Type II – mature onset diabetes,

often individuals are overweight,

may be controlled with diet

Insulin injections are used to treat diabetes

Hypoglycemia = low blood sugarDiabetic neuropathies

People with diabetes can develop nerve

damage throughout the body. Symptoms

include pain, tingling, or numbness-loss of

feeling-in the hands, arms, feet, and legs.

This can result in wounds that are slow to

heal.Diabetes Insipidus

- an uncommon condition that occurs

when the kidneys are unable to

conserve water

The amount of water conserved is

controlled by antidiuretic hormone

(ADH)

Symptoms

- Excessive thirst

- Excessive urine volumeOther Endocrine Glands

Pineal Gland –

- secretes melatonin,

- maintains Circadian rhythms

(light and dark activity)Thymus Gland – large in young children, gradually shrinks

with age, secretes thymosins, important to immune function

Located above heartReproductive Glands – testes and ovaries

– testosterone, progesterone, estrogen

GONADOTROPINS - include any hormone that affect the gonads