Unit 6 Endocrine System Thyroid Gland pt. 1

Endocrine System

Endocrine glands = hormone makers 🧪

• Glands release hormones directly into the bloodstream so they can travel around the body and send messages.

Hormone control:

• ⚡ Metabolism → how your body uses energy

• 📈 Growth & development → growing and body changes

• 🧠 Tissue function → how organs and tissues work

Negative Feedback System (Body's Balance System) 🔄

Think: “Too low = make more, Too high = stop.”

⬇ Hormone level is low
→ Body senses it
→ Sends signal (RF)
→ Makes more hormone

⬆ Hormone level is too high
→ Body senses enough hormone is present
→ Stops hormone production

Memory trick:
“Low = Go, High = Halt”
(Low hormones → Go make more | High hormones → Halt production)

• Negative feedback system: 

  • decrease of hormone level → RF, more is produced

  • hormone level is too high → production stops

Endocrine Glands (Super Easy) 🧠

Think: “Glands = make hormones that control the body”

1. Pancreas 🍬
→ Controls blood sugar

• Makes insulin (lowers sugar)

• Makes glucagon (raises sugar)

2. Pituitary Gland 👑 (Master gland)
→ Controls other glands

• Previous = makes hormones that control growth, thyroid, adrenal, etc.

• Posterior = releases hormones made by the brain (like ADH & oxytocin)

3. Thyroid Gland 🦋
→ Controls metabolism (how fast your body uses energy)

4. Parathyroid Glands 🦴
→ Controls calcium levels in the blood

5. Adrenal Glands ⚡
→ Helps with stress response

• Makes hormones like cortisol and adrenaline

6. Gonads ❤
→ Control sex hormones and reproduction

• Male = testes → testosterone + sperm

• Female = ovaries → estrogen + eggs

Quick Memory Trick:

“PPT PAGG”
Pancreas = sugar
P ituitary = boss
T hyroid = metabolism
P arathyroid = calcium
A drenal = stress
G onads = reproduction

Think: Sugar → Boss → Energy → Calcium → Stress → Sex ✅

Hypothalamus (Super Easy) 🧠

Hypothalamus = the boss that controls the pituitary gland 👑

Think of it like a manager telling an employee what to do:

🧠 Hypothalamus (manager)
⬇ sends releasing factors (RF) = signals/messages
⬇
👑 Pituitary gland (master gland)
⬇ releases hormones that control other glands

Simple steps:

1. Hypothalamus checks what the body needs

2. It sends RF signals

3. Pituitary gland receives the signal

4. Pituitary releases hormones to control the body
   “Hypothalamus = tells, Pituitary = does” ✅

• Hypothalamus = the controller

• Pituitary gland = the hormone maker

Pituitary Gland (Super Easy) 🧠👑

Pituitary gland = “Master gland”
→ Controls many other endocrine glands

It has 2 lobes:

1. Anterior Lobe: (Adenohypophysis) ⭐

• Makes and releases hormones

• Controls things like growth, thyroid, adrenal glands, and reproduction

2. Posterior Lobe (Neurohypophysis) ⭐

• Stores and releases hormones made by the hypothalamus

• Releases ADH (water balance) and Oxytocin (labor/milk)

“ ANTERIOR = Acts (makes hormones)”
“Posterior = Passes along (releases stored hormones)” ✅

Think:
🧠 Hypothalamus = sends the message
👑 Pituitary = carries out the job

• Anterior Lobe: Adenohypophysis
  Adenohypophysis (Anterior Pituitary) —

→ It makes and releases tropic hormones
→ Tropic hormones = hormones that tell other glands/organs what to do

Think: “Previous Pituitary = sends orders” 📩

Main Hormones:

1. TSH (Thyroid Stimulating Hormone) 🦋
→ Tells the thyroid gland to release thyroid hormones
→ Controls metabolism/energy

2. GH (Growth Hormone / Somatotropin) 📈
→ Makes the body grow
→ Increases cell size and growth

3. Prolactin 🍼
→ Stimulates milk production

4. ACTH (Adrenocorticotropic Hormone) ⚡
→ Tells adrenal glands to make cortisol
→ Helps with stress response

5. FSH (Follicle Stimulating Hormone) 🥚
→ Controls sperm and egg (ova) development
→ Helps produce sex hormones

6. LH (Luteinizing Hormone) ❤
→ Controls production of sex hormones
→ Helps with reproduction

Easy Memory Trick:

“FLAT PG”

• F SH = Fertility (eggs/sperm)

• L H = Love hormones (sex hormones)

• A CTH = Adrenal cortisol

• T SH = Thyroid

• P rolactin = Production of milk

• GH = Growth

Big picture:
🧠 Hypothalamus → tells → 👑 Previous Pituitary → sends hormones → 🦋 other glands/organs respond.

Hormones Released
from Neurohypophysis (Posterior Pituitary)

easy

Posterior pituitary = stores and releases hormones made by the hypothalamus

It releases 2 main hormones:

1. Oxytocin ❤
→ Helps with labor contractions
→ Helps with milk release during breastfeeding

2. ADH (Antidiuretic Hormone) 💧
→ Controls water balance
→ Tells the kidneys to save water (less water lost in urine)

“Later = Holds & Helps”

• Oxytocin = Outside baby (birth + milk)

• ADH = Adds water back ✅

Oxytocin — Super Easy 🍼❤

Oxytocin = “contraction hormone”

📍Where does it come from?
→ Released by the posterior pituitary
→ Can also be given as a synthetic drug (man-made oxytocin)

What does it do? (MOA = how it works)

Oxytocin makes smooth muscles contract :

1. Uterus contraction 🤰
→ Makes the uterus squeeze
→ Helps start labor ( induction )
→ Helps strengthen labor contractions ( augmentation )

2. Milk release 🍼
→ Helps push milk out during breastfeeding

3. Stops postpartum bleeding 🩸
→ After birth, uterine contractions squeeze blood vessels closed
→ Helps prevent too much bleeding

Oxytocin = “OXY = Out”
➡ Pushes baby out
➡ Pushes milk out
➡ Pushes bleeding to stop by tightening the uterus ✅

1. ADDITIONAL ENDOCRINE SYSTEM DRUG THERAPY

Posterior Pituitary

oxytocin                              Pitocin®

ADH (Antidiuretic Hormone) — Super Easy 💧

ADH = “water-saving hormone”

📍Where does it come from?
→ Released by the posterior pituitary
→ Can also be given as a synthetic drug

What does ADH do? (MOA)

ADH controls how much water the body keeps .

⬆ More ADH = Save more water 💧
→ Kidneys reabsorb more water
→ Less water leaves the body
→ Less urine

⬇ Less ADH = Lose more water 🚽
→ Kidneys keep less water
→ More water leaves the body
→ More urine

Diabetes Insipidus (Low ADH problem)

If ADH is too low:

• 🚽 Lots of dilute, watery urine

• 🥤 Very thirsty ( polydipsia )

• 💧 Can become dehydrated

Easy Memory Trick:

ADH = “Add Dehydration Help”
➡ ADH adds water back into the body ✅

Think: ADH tells the kidneys: “Don't waste water!” 💧

1. ADDITIONAL ENDOCRINE SYSTEM DRUG THERAPY

2.          antidiuretic hormone/vasopressin          ADH drug

desmopressin DDAVP®

Adrenal Glands (Super Easy) ⚡

Adrenal glands = stress hormone glands
📍 Located on top of the kidneys (suprarenal = “above the kidney”)

They have 2 parts:

1. Inner Part = Medulla ⚡

→ Makes catecholamines

• EPI (epinephrine/adrenaline)

• NE (norepinephrine)

Job: 🚨 “Fight or flight” response
→ Increases heart rate, energy, and alertness

2. Outer Part = Cortex 🧪

→ Makes corticosteroids

Two main types:

• Glucocorticoids (cortisol) → helps with stress and metabolism

• Mineralocorticoids (aldosterone) → controls salt and water balance

“M&M = Medulla Moves fast, Cortex Controls chemistry” ✅

• Medulla = Emergency (EPI/NE) 🚨

• Cortex = Cortisol + salt/water control 💧

• Inner part-medulla

  • Secretes catecholamines (EPI/NE)
    
    

Glucocorticoids (Cortisol & Cortisone) — Super Easy 🧠

Glucocorticoids = stress + inflammation hormones
Main examples: Cortisol and Cortisone

What do they do? (MOA)

✅ Metabolism control

• Help the body use carbohydrates (sugar) and proteins for energy

✅ Reduces inflammation 🔥⬇

• Calm down the immune response

• Decrease swelling, redness, and irritation

How is cortisol made? (Simple pathway)

🧠 Hypothalamus
⬇ releases CRF (message)
👑 Previous Pituitary
⬇ releases ACTH (another message)
⚡ Adrenal Cortex
⬇ makes cortisol

Think:
Hypothalamus → Pituitary → Adrenal Cortex → Cortisol

Uses of Glucocorticoids:

💊 Hormone replacement
→ Replaces cortisol if the body does not make enough

🔥 Treat inflammation/allergies
→ Arthritis
→ Asthma
→ Skin irritation

Memory Trick:

“Cortisol = Controls + Calms” ✅

• Controls metabolism

• Calms inflammation

Glucocorticoids MOA (How They Work) — 🧠

Glucocorticoids = raise blood sugar + reduce inflammation

1. Increase blood glucose 🍬

• They stop fat cells from taking in glucose
  → More glucose stays in the blood
  → Blood sugar increases

2. Make more glucose (Gluconeogenesis) ⚡

• The liver makes new glucose for energy

• Uses proteins → amino acids → glucose

• This gives energy to injured tissues and the brain

3. Suppress the immune system 🛑🦠

• They slow down the immune response

• This prevents the body from overreacting

4. Anti-inflammatory effect 🔥⬇

• Decreases inflammation

• Reduces swelling, redness, and irritation

Easy way to remember:

“Glucocorticoids = Sugar Up, Immune Down” ✅

⬆ Blood glucose
⬇ Immune response
⬇ Inflammation

• 2. Stimulate gluconeogenesis

  • Increase in production of glucose for use by injured tissue or by the brain

  • Protein catabolism

  • Proteins to amino acids to make glucose

Adrenal Cortex

Corticosteroids

 Glucocorticoids

drug

hydrocortisone                    Cortef®, Cortaid® (OTC topical)

methylprednisolone            Medrol®

prednisolone                  

triamcinolone                      Kenalog® 

betamethasone                    Celestone®

dexamethasone                   

prednisone

Glucocorticoids Side Effects & Patient Teaching — Super Easy 🧠

Think: Glucocorticoids = “More sugar + weaker immune system”

Common Side Effects (Short-term)

🍽 Increased appetite → want to eat more
😡 “Roid rage” → mood changes/irritability
🤢 Indigestion → stomach upset
😴 Restlessness + trouble sleeping → feel wired
🔴 Facial flushing → red/warm face
😊 Euphoria → feeling unusually happy

Cushing's Disease Signs (Too much cortisol)

🌙 Moon face → round, puffy face
🐃 Buffalo hump → fat buildup on upper back
⚖ Weight gain/obesity

Long-Term Therapy Adverse Effects1. Increased glucose production 🍬

→ More gluconeogenesis (making glucose)
→ High blood sugar (hyperglycemia)
→ Can lead to diabetes mellitus

2. Protein breakdown 💪

→ Proteins are broken down
→ Muscle weakness and wasting
→ Thinner skin

3. Bone effects 🦴

→ Decreases bone strength
→ Osteoporosis (weak bones)

4. Immune system effects 🦠

→ Decreases white blood cells ( leukopenia )
→ Body fights infection less effectively
→ Increased infections

5. Healing effects 🩹

→ Slows tissue repair
→ Decreased wound healing

Glucocorticoids

easy summary

“CORTISOL COSTS” 💰

C = Cushing signs (moon face, buffalo hump)
O = Osteoporosis
S = Sugar goes up
T = Thinner skin
S = Slow healing
I = Infections increase
L = Less immune response

Big picture:
Glucocorticoids calm inflammation ✅ but too much for too long can cause high sugar, weak muscles/bones, and weaker immunity .

Cushing's Disease — Super Easy 🧠

Cushing's Disease = too much cortisol in the body ⚡
→ Usually happens when the body makes too much cortisol (or from long-term glucocorticoid use)

What happens with too much cortisol?

⬆ Blood pressure (Hypertension) ❤
→ Cortisol causes the body to hold onto fluid and increases pressure

💧 Edema
→ Extra fluid builds up → swelling

🌙 Moon face
→ Fat builds up in the face → round, puffy face

🐃 “Buffalo hump”
→ Fat builds up on the upper back/neck area

🍔 Protruding abdomen
→ Fat increases around the belly

💪 Thin arms and legs
→ Cortisol breaks down proteins → muscle loss and weakness

Easy Memory Trick:

“Cushing = Cushiony in the middle”

• Round face 🌙

• Fat back 🐃

• Big belly 🍔

• Thin limbs 💪

Big picture: Too much cortisol causes fat buildup in certain areas + muscle breakdown + fluid retention . ✅

Glucocorticoids

Cortisol = the body's stress hormone
→ The body releases cortisol when it feels it needs extra energy or protection

• Factors that trigger cortisol release:  Cortisol increases with:

😰 Stress → body prepares to handle a challenge
🏃 Exercise → provides extra energy for muscles
❄ Cold weather → helps the body respond to cold
🦠 Infection → helps fight stress from illness
😟 Anxiety → emotional stress increases cortisol
🏥 Surgery → body sees it as a stress event
🩹 Body injury → helps the body respond and heal

Easy Memory Trick:

“SICK STRESS = CORTISOL”

• Surgery​

• Injury​

• Cold​

• K (think “sick” = infection)

• Stress/anxiety

• Exercise

Big picture:
When the body is under stress → 🧠 hypothalamus → pituitary → adrenal cortex → releases cortisol to help the body cope. ✅

Negative Feedback Mechanism (Cortisol) — Super Easy 🧠

Negative feedback = the body's “stop and balance” system 🔄

How it works:

1⃣ Cortisol is too low
→ Hypothalamus releases releasing factor (RF)
→ Pituitary releases corticotropin/ACTH
→ Adrenal gland releases cortisol into the bloodstream ⚡

2⃣ Cortisol levels rise ⬆
→ Body senses there is enough cortisol
→ Stops releasing RF and ACTH 🛑

3⃣ Cortisol production decreases
→ Keeps cortisol levels balanced ✅

Easy Memory Trick:

“Low = Let it Go, High = Halt”

⬇ Low cortisol → make more
⬆ High cortisol → stop doing more

Big picture:
Hypothalamus → ACTH → Adrenal gland → Cortisol
Then cortisol says: “I'm enough, stop sending signals.” ✅

• Maintains balance of cortisol levels

Addison's Disease — Super Easy 🧠

Addison's Disease = too little adrenal hormones ⚡
→ The adrenal glands do not make enough steroids :

• Glucocorticoids (cortisol)

• Mineralocorticoids (aldosterone)

What happens when hormones are too low?

💧 Dehydration
→ Less aldosterone = less water and salt kept in the body

⬇ Hypotension (low blood pressure)
→ Losing salt + water lowers blood volume

⚖ Weight loss
→ Less cortisol affects metabolism and energy

💪 Muscle atrophy
→ Muscle weakness and loss of muscle tissue

Easy Memory Trick:

“Addison = Adrenal is Absent” ❌
Think: “Low hormones = Low everything”

⬇ Cortisol + aldosterone
⬇ Water
⬇ Blood pressure
⬇ Weight + muscle

Big picture:
Addison's = not enough adrenal hormones → dehydration, low BP, weight loss, and muscle weakness ✅

• too little steroid production (mineralocorticoids & glucocorticoids)

• Symptoms: dehydration, hypotension, weight loss, muscle atrophy