Anatomy-Endocrine Final SG

True or False: The endocrine system works closely with the nervous system to coordinate body functions?

True

What are the functions of the endocrine system?

• Growth & Development

• Homeostasis

• Metabolism

• Reproduction

• Stress Response

What is the difference between the nervous system and the endocrine system?

Nervous System

• Fast (milliseconds)

• Electrical + neurotransmitters

• Short-lasting, precise

Endocrine System

• Slower

• Hormones via bloodstream

• Long-lasting, widespread effects

What are hormones and what do they do?

• Chemical messengers released into blood

• Only affect target cells with receptors

• Can:

  • Stimulate OR inhibit activity

• Controlled mostly by negative feedback

• Very potent (small amounts = big effects)

What are the two types of hormones?

• Amino Acid–Based (water-soluble)

• Steroid Hormones (lipid-soluble)

What are the unique features of amino acid-based hormones?

• Cannot cross membrane

• Bind to surface receptors

• Water-soluble

• Examples:

  • Peptides (insulin, oxytocin)

  • Monoamines (dopamine, melatonin)

What are the unique features of steroid hormones?

• Derived from cholesterol

• Cross cell membrane

• Act inside cell (nucleus)

• Lipid-soluble

• Examples:

  • Estrogen

  • Cortisol

What are the differences between endocrine vs. exocrine glands?

Endocrine

• Ductless

• Release hormones → blood

• Highly vascular (fenestrated capillaries)

Exocrine

• Have ducts

• Release onto surfaces (skin, GI tract)

What are the functions of the hypothalamus (master control) in regards to the endocrine system?

• Water balance

• Temperature regulation

• Sex drive

• Childbirth

What are the 3 control mechanisms of the hypothalamus?

1. Controls posterior pituitary (ADH, oxytocin)

2. Controls anterior pituitary via releasing hormones

3. Controls adrenal medulla via nerves

What is the pituitary gland known as?

Master Gland

The anterior pituitary gland is also known as...?

Adenohypophysis

The posterior pituitary gland is also known as...?

Neurohypophysis

What is the function of the posterior pituitary gland, and what hormones are involved?

• Stores/releases hypothalamus hormones

• DOES NOT produce hormones

Hormones:

• ADH (antidiuretic hormone)

  • Reduces urine → conserves water

• Oxytocin

  • Labor contractions

  • Milk ejection

What is the function of the anterior pituitary gland, and what hormones are involved?

(Tropic = control other glands)

• TSH → thyroid

• ACTH → adrenal cortex

• GH → growth, metabolism

• PRL → milk production

• FSH → sperm/egg development

• LH → ovulation/testosterone

• MSH → skin pigmentation

What are some pituitary disorders?

• Hypersecretion GH

  • Gigantism (kids)

  • Acromegaly (adults)

• Hyposecretion GH

  • Dwarfism

What function does the thyroid gland play in the endocrine system, and what hormones are involved?

• Located on trachea (butterfly shape)

• Highly vascular

Hormones:

• T3 & T4

  • Increase metabolism

• Calcitonin

  • ↓ blood Ca²⁺ (inhibits osteoclasts)

Regulation:

• Controlled by TSH

What function does the parathyroid gland play in the endocrine system, and what hormones are involved?

• 4 small glands behind thyroid

Hormone:

• PTH (parathyroid hormone)

  • ↑ blood Ca²⁺

  • Stimulates osteoclasts

  • ↓ urinary Ca²⁺ loss

  • ↑ absorption in intestines

👉 Opposite of calcitonin

What is the adrenal glands also known as, and what are the structures?

• “Suprarenal”

• Cortex (outer)

• Medulla (inner)

What do the 3 layers of the adrenal cortex produce?

Produces steroid hormones:

• Aldosterone

  • ↑ blood volume & BP

• Cortisol

  • ↑ glucose, stress response

• Androgens/Estrogens

  • Sex hormones

What is the adrenal medulla part of and what hormones do they produce?

• Part of sympathetic nervous system

Hormones:

• Epinephrine (adrenaline)

• Norepinephrine

👉 “Fight or flight”

• ↑ heart rate

• ↑ BP

• ↑ alertness

What type of gland is the pancreas?

Endocrine + Exocrine glands

What cells are in the pancreatic islets, and what do they produce?

• Alpha cells → glucagon (↑ glucose)

• Beta cells → insulin (↓ glucose)

• Delta cells → somatostatin (slows digestion)

• F cells → pancreatic polypeptide

What is the role of the pineal gland, and what does it produce?

• Produces melatonin

• Controls sleep cycle

• Light ↓ melatonin

• Darkness ↑ melatonin

What are the two types of gonads?

• Testes

• Ovaries

What hormones are involved in the testes, and what do they do?

• Testosterone

  • Sperm production

  • Male traits

• Inhibin

  • Regulates sperm production

What hormones are involved in the ovaries, and what do they do?

• Estrogen (estradiol)

  • Egg development

• Progesterone

  • Prepares uterus

• Inhibin

  • ↓ FSH

How do feedback loops work in the endocrine system?

Type	Description	Example
Negative Feedback	Output reduces stimulus	T3/T4 reduce TSH
Positive Feedback	Output increases stimulus	Oxytocin during labor

What is hyposecretion?

too little hormone

What is hypersecretion?

too much hormone

What are some common endocrine thyroid disorders?

• Hypothyroidism

  • Congenital (cretinism)

  • Myxedema (adult)

• Goiter

  • Enlarged thyroid (iodine deficiency)

• Graves disease

  • Hyperthyroidism (autoimmune)

What are some common endocrine parathyroid disorders?

• Hypoparathyroidism

  • Low Ca²⁺ → tetany (fatal)

• Hyperparathyroidism

  • Weak bones, kidney stones

What is a common endocrine adrenal disorders?

Cushing Syndrome

• Too much cortisol

• Symptoms:

  • Hyperglycemia

  • Fat redistribution (“moon face”)

  • Muscle loss

What are the symptoms of diabetes mellitus?

• Polyuria (urine)

• Polydipsia (thirst)

• Polyphagia (hunger)

What are the 2 types of diabetes mellitus?

Type 1

• Autoimmune

• No insulin

• Requires insulin therapy

Type 2

• Insulin resistance

• Risk factors:

  • Obesity

  • Age

  • Genetics

What role does pathogenesis play in regards to diabetes mellitus?

• Cells can’t use glucose

• Use fat → ketones → ketoacidosis

• Long-term:

  • Nerve damage

  • Cardiovascular disease

  • Kidney/eye damage

What does insulin do?

Lowers blood glucose

What does glucagon do?

Raises blood glucose

What does calcitonin do?

Lowers blood Ca²⁺

What does parathyroid hormone (PTH) do?

Raises blood Ca²⁺

What does T3 & T4 hormones do?

Speed up metabolism (energy use)

What does antidiuretic hormone (ADH) do?

Saves water → less urine

What does oxytocin do?

Causes labor contractions & milk release

What does thyroid stimulating hormone (TSH) do?

Tells thyroid to make hormones

What does adrenocorticotropic hormone (ACTH) do?

Tells adrenal gland to release stress hormones

What does growth hormone (GH) do?

Makes you grow; builds muscle & tissue

What does prolactin (PRL) hormone do?

Makes breast milk

What does follicle-stimulating hormone (FSH) do?

Helps make sperm & eggs

What does luteinizing hormone (LH) do?

Triggers ovulation & testosterone release

What does melanocyte-stimulating hormone (MSH) do?

Affects skin pigment (melanin)

What does cortisol do?

Stress hormone → raises blood sugar

What does the aldosterone hormone do?

Keeps salt & water → raises blood pressure

What does Epinephrine (adrenaline) do?

Fight-or-flight → ↑ heart rate, energy

What does norepinephrine do?

Helps raise blood pressure & alertness

What does somatostatin hormone do?

Slows digestion & hormone release

What does melatonin do?

Controls sleep cycle

What does testosterone do?

Male traits & sperm production

What does estrogen do?

Female traits & cycle regulation

What does progesterone do?

Prepares uterus for pregnancy

What does the hormone inhibin do?

Slows sperm/egg production