Endocrine System Flashcards
It is a network of glands and organs that produce, store, and release hormones.
Endocrine System
These are chemical messengers that regulate many vital body functions, such as growth, metabolism, reproduction, mood, and overall homeostasis (balance in the body).
Hormones
It is known as the “master gland”.
It is located in the brain and acts as the bridge between the nervous system and the endocrine system.
It controls the pituitary gland by producing releasing and inhibiting hormones, which regulate the secretion of hormones from the pituitary.
Hypothalamus
Add: Without the hypothalamus, the pituitary gland would not function properly.
What is the series of process that happens when we need to release hormones needed by the body?
Homeostasis → Hypothalamus → Pituitary gland → Glands → Negative feedback
Note:
- Homeostasis is the body’s way of maintaining a stable internal environment (ex: temperature, blood sugar, and hydration).
- Hypothalamus: Detects imbalances (ex: low blood sugar or high body temperature) and sends signals.
- Pituitary Gland: Receives instructions from the hypothalamus and releases hormones to target glands.
- Glands: (ex: thyroid, adrenal glands) respond by releasing specific hormones to restore balance.
- Negative Feedback: Once balance is achieved, signals are sent back to stop hormone production to avoid overcorrection.
This loop keeps the body’s systems in harmony.
FAMILIARIZE ONLY!
What are the Functions of the Endocrine System?
- Metabolism (Use of energy)
- Control of food intake and digestion
- Tissue development
- Ion regulation
- Water balance
- Heart rate and blood pressure regulation
- Control of blood glucose and other nutrients
- Control of Reproductive functions
- Uterine contraction and milk release
- Immune System regulation
Why do we need to memorize all the hormones?
Because we take them as drugs (hormonal drugs).
It’s function is to secrete hormones directly into the bloodstream.
It has no ducts, so hormones travel through the blood to target organs or tissues.
Endocrine glands
Note:
- Endocrine glands regulate internal processes via hormones.
It’s function is to release substances (not hormones) to specific body surfaces or cavities (outside the body).
It use ducts to transport secretions.
Exocrine glands
Note:
- Exocrine glands provide localized secretions like enzymes or sweat.
There are terms that describe the 3 different mechanisms of how hormones are stimulated.
What are these?
- Humoral stimuli
- Neural control
- Hormonal release
Hormone release is triggered by changes in the levels of certain substances in the blood, such as ions or nutrients.
Example:
- Low calcium levels in the blood stimulate the parathyroid glands to release parathyroid hormone (PTH), which raises calcium levels.
Humoral stimuli
Note: Circulate in the blood (plasma)
Hormone release is controlled directly by the nervous system or specifically brain. This is where neurons send action potentials to stimulate hormone.
Example:
- During stress, the sympathetic nervous system signals the adrenal medulla to release adrenaline (epinephrine) for a “fight-or-flight” response.
Neural control
Hormone release is regulated by other hormones. It has direct effect on gland.
Example:
- The hypothalamus secretes releasing hormones that stimulate the pituitary gland to release hormones (ex: thyroid-releasing hormone stimulates thyroid-stimulating hormone).
Hormonal release
Note: Hormone affects or stimulates another hormone.
It is a small, pea-shaped gland located at the base of the brain, just below and controlled by the hypothalamus.
Pituitary gland
The pituitary gland has two distinct parts, which differ in structure, function, and the hormones they release.
What are these?
- Anterior Pituitary Gland (APG)
- Posterior Pituitary Gland (PPG)
It produces and secretes hormones in response to releasing or inhibiting hormones from the hypothalamus as it is under the control of it.
Anterior Pituitary Gland (APG)
Note: We have 6 hormones here
Does not produce hormones but stores and releases hormones made by the hypothalamus.
Posterior Pituitary Gland (PPG)
Note: We have 2 hormones here.
What is the main difference between Anterior Pituitary Gland (APG) and Posterior Pituitary Gland (PPG)?
APG
- Produces hormones.
PPG
- Stores hormones from hypothalamus.
What are the 6 Main Hormones of Anterior Pituitary Gland (APG)?
- Growth Hormone (GH)
- Adrenocorticotropic Hormone (ACTH)
- Thyroid-Stimulating Hormone (TSH)
- Gonadotropin Hormones (FSH and LH)
→ Follicle-Stimulating Hormone (FSH)
→ Luteinizing Hormone (LH)
- Melanocyte-Stimulating Hormone (MSH)
- Prolactin (PRL)
REMEMBER THE ACRONYM GAT-GMP
It’s function is to stimulate the growth of bones (epiphyseal plate), muscles, and organs.
Growth Hormone (GH)
Excessive or too much Growth Hormone causes _______.
This is the abnormal growth of bones and tissues, leading to extreme height and large body size.
Giantism
Insufficient or little secretion of growth hormone during childhood causes ______.
Symptoms:
- Short stature compared to peers.
- Delayed growth and development.
- Stunted growth but normal body proportions.
Pituitary dwarfism
Stimulates the thyroid gland to release thyroid hormones (T3 and T4), regulating metabolism.
Thyroid - Stimulating Hormone (TSH)
What are the hormones produced by the thyroid gland?
Make sure to include the full name.
- T3 (triiodothyronine)
- T4 (thyroxine)
Too much TSH causes the thyroid gland to _____.
enlarged
Note: This is goiter.
Too little TSH causes the thyroid gland to ______.
shrink
Hormone that regulate reproductive functions.
Gonadotrophin Hormone LH and Gonadotrophin Hormone FSH
Or just
LH and FSH
What is the target tissue and function of Luteinizing Hormone (LH) for male and female?
Females:
- Target is ovaries.
- Promotes ovulation and production of progesterone
Males:
- Target is testes.
- For sperm production and testosterone
What is the target tissue and function of Follicle-Stimulating Hormone (FSH) for male and female?
Females:
- Target tissue: Follicles in ovaries
- Function: Follicle maturation and estrogen secretion
Males:
- Target tissue: seminiferous tubules testes
- Function: sperm production
What is the target tissue and function of Prolactin (PRL)?
Target tissues: mammary glands and ovaries
Functions: milk production
Affects skin pigmentation by stimulating melanin production (minimal role in humans).
Melanocyte Stimulating Hormone (MSH)
Note: pampaitim daw HAHAHAHA
Stimulates the adrenal cortex to produce corticosteroids or cortisol (stress hormone).
Adrenocorticotropic Hormone (ACTH)
What are the 2 Main Hormones of Posterior Pituitary Gland (PPG)?
- Oxytocin
- Antidiuretic Hormone (ADH)
REMEMBER THE ACRONYM OA
It facilitates uterine contractions during childbirth, promotes milk ejection during breastfeeding, and strengthens social bonding.
It’s target is the uterus and mammary glands.
Oxytocin
Note: This is to induced labor (para mapaanak na yung patient) or after delivery ginagamit siya to reduced bleeding.
Helps maintain water balance (conserve water or reabsorption of water) in the body by acting on the kidneys.
Antidiuretic Hormone (ADH)
Note: This is also about the concentration of urine.
When you have high levels of Antidiuretic hormones, what would be the color of your urine?
Yellow or darker
Note: This means that you are dehydrated and your ADH level is increased.
When you have low levels of Antidiuretic hormones, what would be the color of your urine?
White or pale yellow
Note: This means you are hydrated and your ADH level is decreased.
This is a rare condition that occurs when the body cannot properly regulate water balance due to a problem with the production (low ADH) or action of antidiuretic hormone (ADH), also known as vasopressin. This leads to excessive thirst and urination.
Diabetes insipidus (DI)
Note: Eto yung kinuwento ni sir about his patient na naaksidente and nagkaroon ng ganitong condition. This leads to dehydration and naging brain dead yung patient.
It is one of the largest glands. It also requires iodine to function.
Thyroid Gland
Note: Seafoods can be a source of Iodine.
Remember that Iodine is important as it helps the thyroid gland to release its hormones.
What are the hormones secreted by the thyroid gland?
- Thyroid Hormone (T3 and T4.
- Calcitonin
It is secreted by the Thyroid gland and its function is to regulate metabolic rates and is needed for growth.
Thyroid Hormones
T3 and T4
Note: Their differences lies with the number of iodine atoms present in them. T3 has 3 and T4 has 4.
It is secreted by the thyroid gland and its function is to reduce blood calcium levels when high.
Calcitonin
Note: Lowers blood calcium levels by inhibiting calcium release from bones and increasing calcium excretion in urine.
What are the 2 thyroid disorders caused by abnormal production of thyroid hormones (T3 and T4) by the thyroid gland?
These conditions affect metabolism, energy levels, and various bodily functions.
Hypothyroidism and Hyperthyroidism
This is a thyroid hormone disorder where the thyroid gland produces insufficient thyroid hormones (Low T3 and T4).
Symptoms:
- Slowed metabolism
- Weight gain, reduced appetite, fatigue
- Low temperature
- Slowed heart rate
- Dry, cold skin
- Myxedema in adults (swelling and thickening of skin)
- Cretinism in infants (delayed development physically and mentally).
- Low IQ
Hypothyroidism
This is a thyroid hormone disorder where the thyroid gland produces excessive thyroid hormones (High T3 and T4).
Symptoms:
- Accelerated metabolism
- Weight loss, increased appetite, nervousness
- Higher temperature
- Rapid heart rate
- Warm, flushed skin
- Graves’ disease (leads to goiter)
- Insomnia (restlessness)
- Flight ideas
Hyperthyroidism
These are four small, pea-shaped glands located behind the thyroid gland in the neck. They play a crucial role in regulating calcium levels in the blood and bones.
Parathyroid gland
What hormone does the Parathyroid gland produces?
Function: Primary regulator of calcium and phosphate levels in the blood.
Parathyroid Hormone
Note: This is to increase calcium blood levels and break down bones.
What is the difference between Calcitonin and Parathyroid Hormone in terms of blood calcium level?
Calcitonin (Thyroid Gland)
- Lowers blood calcium levels when they are too high.
Parathyroid Hormone (Parathyroid Gland)
- Raises blood calcium levels when they are too low.
Hormone that lowers blood calcium levels when they are too high.
Calcitonin
Hormone that raises blood calcium levels when they are too low.
Parathyroid Hormone
These are two small, triangular-shaped glands located on top of each kidney. They play a crucial role in producing hormones that regulate metabolism, immune response, blood pressure, stress response, and other vital functions.
Adrenal Gland
The adrenal glands consist of two main parts, each with distinct functions. What are these?
- Adrenal Medulla (Inner Layer)
- Adrenal Cortex (Outer Layer)
The Adrenal medulla produces two hormones and it is released as part of fight or flight response (life threatening).
What are these?
Epinephrine and Norepinephrine
Note: The problem with these is that it only lasts from 5-10 mins only.
This is for heart rate. When cardiac arrest happens (no heart rate), this is injected.
Epinephrine
This is for blood pressure. When shock happens to a patient, this will increase the blood pressure of the patient.
Norepinephrine
The Adrenal Cortex produces 3 Hormones. What are these?
- Aldosterone (mineralocorticoids)
- Cortisol (glucorticoids)
- Androgens
It is a type of mineralocorticoids. The target organ is kidney.
Regulates blood pressure by controlling sodium and potassium levels.
Aldosterone
Note: Whenever there is sodium, water follows.
The problem here is the excretion of potassium because less potassium can lead to heart problems.
It is a type of glucocorticoids.
Manages stress by increasing blood glucose, suppressing inflammation, and aiding metabolism.
Cortisol
It can cause imbalances. Nakakapanget daw. Cause acne, eye bags, and fats.
Tumataas Ang stress levels kapag mataas ang cortisol.
Precursors to sex hormones; important during puberty.
In males, it is important for secondary Sexual characteristics.
For females, it is for sex drive. However too much of this hormone, leads to hirsutism (girls got mustache)
Androgens
It is a dual-function organ, acting as both an endocrine gland (hormone secretion) and an exocrine gland (digestive enzyme production).
Its actions are critical for regulating blood sugar levels and aiding digestion.
Pancreas
The pancreas is a mixed gland. What are the 2 portion of it?
Endocrine and exocrine portion
Note: We will only focus on the Endocrine part
The Endocrine part of the pancreas consists of pancreatic islets or what we call the __________, which are dispersed throughout the exocrine portion of the pancreas.
Islets of Langerhans
The islets consist of three cell types, each of which secretes a separate hormone. What are these?
- Alpha cells
- Beta cells
- Delta cells
Note: These three hormones regulate the blood levels of nutrients, especially glucose.
Alpha cells secretes what hormone?
Glucagon (Violet)
Beta cells secretes what hormone?
Insulin (Blue)
Delta cells secretes what hormone?
Somatostatin
Note: This is not important.
(a) Raises blood sugar levels.
(b) Lowers blood sugar levels
(a) Glucagon
(b) Insulin
What are the target tissues of Insulin?
- Liver
- Skeletal muscle
- Mostly adipose tissue
Extra glucose is stored in the form of _________ in the liver.
glycogen
What is the normal blood sugar?
80 - 120
This is a specialized organ of the immune system that plays a key role in the development and maturation of T-lymphocytes (T-cells), which are critical for adaptive immunity.
Thymus Gland
This is a hormone produced by the thymus gland that plays a crucial role in the development and regulation of the immune system.
Thymosin
This is a small, pea-shaped gland in the brain that plays a key role in regulating the body’s biological rhythms and Circadian rhythms or sleep-wake cycle.
Pineal Gland
What is the hormone produced by the Pineal Gland?
- Secreted in response to darkness and inhibited by light.
- Helps regulate sleep-wake cycles by signaling the body when it’s time to sleep.
Melatonin
This is a chronic metabolic disorder characterized by high blood sugar levels (hyperglycemia) due to problems with insulin production, action, or both.
This is caused by too little insulin.
Diabetes Mellitus
What are the 2 Types of Diabetes Mellitus?
- Type I
- Type II
This is the type of Diabetes Mellitus where the patient is insulin dependent and daily injections required.
Type I
This is the type of Diabetes Mellitus where the patient is insulin independent, often found in obese people, can be treated with diet but can turn into type I.
Type II
