Endocrine - Pituitary Hormone-1

Question 1

What are the structural difference between the adenohypophysis and neurohypophysis?

Answer 1

• Adenohypophysis: Consists of glandular tissue.
• Neurohypophysis: Consists of neural tissue and pituicytes (glial cells)

Question 2

What is the function of adenohypophysis and neurohypophysis?

Answer 2

• Adenohypophysis: Produces and secretes hormones in response to
  hypothalamic signals.
• Neurohypophysis: Stores and releases hormones produced by the
  hypothalamus.

Question 3

What is the regulation of the adenopophysis nd neurohypophysis?

Answer 3

• Adenohypophysis: Regulated by hypothalamic releasing and inhibiting
  hormones via the hypophyseal portal system (Hypothalamus-pituitary axis).
• Neurohypophysis: Directly controlled by nerve signals from the
  hypothalamus

Question 4

What are the hormones released from the anterior pituitary?

Answer 4

*somatotropin
*prolactin
*corticotropin
*thyrotropin
*gonadotropin

Question 5

What are the hormones released by the posterior pituitary?

Answer 5

*oxytocin
*ADH

Question 6

What are the local effects of pituitary tumour?

Answer 6

*headaches
*visual disturbances

Question 7

What do pituitary tumours do?

Answer 7

*can over produce or under produce hormones
*slowly grow over time
*mostly benign

Question 8

What does the hypothalamus do in terms of GH?

Answer 8

• Growth Hormone-Releasing Hormone (GHRH): Stimulates the
  secretion of GH from the anterior pituitary.
• Somatostatin (SS): Inhibits the secretion of GH from the anterior pituitary

Question 9

What does the anterior pituitary do in terms of GH?

Answer 9

• In response to GHRH, acidophilic cells in the anterior pituitary secrete GH.
• GH is then released into the bloodstream in a pulsatile manner.

Question 10

What does the liver do to feedback from the anterior in terms of GH?

Answer 10

Liver: GH stimulates the liver to produce Insulin-like Growth Factor 1 (IGF-1),
which has growth-promoting effects on almost every cell in the body,
especially bone and muscle

Question 11

What is the positive regulation of the GH?

Answer 11

GHRH: Released from the hypothalamus, stimulates GH secretion from the
anterior pituitary.

Question 12

What is the negative regulation of the GH?

Answer 12

• Somatostatin (SS): Released from the hypothalamus, inhibits GH secretion.
• IGF-1: Produced in response to GH, provides negative feedback to both the
  hypothalamus and the pituitary gland to decrease GH production

Question 13

What are the direct effects on metabolism from GH?

Answer 13

*increase blood glucose
*increase gluconeogensis (liver)
*increase protein synthesis (muscle)
*decrease glucose uptake in muscle
*increases lipolysis (adipose)
*decrease glucose uptake in adipose tissue

Question 14

What is the indirect growth effect from GH?

Answer 14

increase hypertrophy (cell size)
*increase protein synthesis
*increase hyperplasia (cell number, cell division)
*increases linear skeletal growth

Question 15

Describe how sleep affects GH release

Answer 15

GH release peaks during deep sleep stages (slow-wave sleep).
*Sleep quality and duration significantly influence GH secretion.
*Poor sleep quality or disorders can impair GH release

Question 16

Describe how exercise affects GH release?

Answer 16

High-intensity and longer-duration exercises stimulate substantial GH release.
*Both resistance and aerobic exercises can increase GH levels, with resistance training
typically having a more pronounced effect.
*GH levels peak shortly after exercise and gradually return to baseline.
*Regular training can enhance the GH response to exercise

Question 17

What are the different types of GH deficiency?

Answer 17

*congenial deficiency
*acquired deficiency
*idiopathic deficiency

Question 18

What are the causes and symptoms of congenital GH deficiency?

Answer 18

*Causes: Genetic mutations or structural issues in the baby’s brain that affect the
development or function of the pituitary gland.
*Symptoms: Poor growth and short stature from birth, delayed puberty, and, in some
cases, hypoglycaemia in infants

Question 19

What are the causes and symptoms of acquired GH deficiency?

Answer 19

Causes: Damage to the pituitary gland or hypothalamus due to injury, infection, tumour,
surgery, or radiation therapy.
*Symptoms: Stunted growth if occurring in children, reduced muscle mass, increased fat
mass, decreased energy levels, and poor quality of life in adults

Question 20

What are the causes and symptoms of idiopathic GH deficiency?

Answer 20

*Causes: Unknown cause; no identifiable genetic, structural, or acquired reasons.
*Symptoms: Similar to congenital and acquired GH deficiency, including short stature,
delayed growth, and other metabolic issues

Question 21

What are the treatment options of GH deficiency?

Answer 21

*GH replacement therapy
*monitoring and support

Question 22

What are some side effects to gigantism/ acromegaly?

Answer 22

• coarsening of facial features
• enlarged hands and feet (arthritis)
• headaches, vision disturbance
• sleep apnoea, general tiredness
• hypertension, cardiomegaly
• glucose intolerance (diabetes)
• irregular or loss of periods (females); impotence
  (males)
• bowel polyps

Question 23

What are the treatment options for excess GH disorders?

Answer 23

*reduce GH levels/block GH action
*surgical removal of the tumour (transsphenoidal surgery) or (stereotactic radio surgery/gama knife)
*radiotherapy

Question 24

What are the functions and effects of thyroxine (T4)?

Answer 24

• Function: Serves as a prohormone and is converted into T3 in peripheral tissues
  *Effects: Influences metabolism, heart rate, and body temperature.
  It also plays a role in growth and development

Question 25

What is the structure and regulation of thyroxine?

Answer 25

* Structure: Contains four iodine atoms *Regulation: Controlled by Thyroid-Stimulating Hormone (TSH) from the anterior pituitary

Question 26

What are the structure and function of Tri-iodothyronnie (T3)?

Answer 26

* Structure: Contains three iodine atoms. * Function: The active form of thyroid hormone, much more potent than T4

Question 27

What is the conversion and effects of T3?

Answer 27

* Conversion: Produced both directly by the thyroid gland and from the conversion of T4 in the liver and other tissues. * Effects: Regulates metabolic rate, enhances oxygen consumption, stimulates protein synthesis, and influences neural development

Question 28

What is the source, function and regulation of calcitonin?

Answer 28

* Source: Produced by the parafollicular cells (C cells) of the thyroid gland. * Function: Lowers blood calcium levels. * Regulation: Secretion is stimulated by high blood calcium levels

Question 29

What is the source, function and regulation of the parathyroid hormone?

Answer 29

* Source: Produced by the parathyroid glands, which are small glands located on the posterior surface of the thyroid gland. * Function: Raises blood calcium levels. * Regulation: Secretion is stimulated by low blood calcium levels.

Question 30

What are the functions of T3?

Answer 30

*basal metabolic rate (BMR) = sugar, fat and protein metabolism *growth and development =CNS development *synergistic effect with SNS =adrenergic receptors = physiological effects

Question 31

What are the causes of thyroid hormone disease?

Answer 31

* Iodine Deficiency: The most common cause worldwide. * Graves' Disease: Causes diffuse enlargement of the thyroid. * Hashimoto's Thyroiditis: Can lead to thyroid enlargement. * Thyroid Nodules: Growth of lumps (cancerous) within the thyroid.

Question 32

What are the symptoms to thyroid disease?

Answer 32

*visible swelling in the neck *difficulty swallowing or breathing (if large)

Question 33

What are the causes of hypothyroidism?

Answer 33

* Hashimoto's Thyroiditis: An autoimmune disorder where the immune system attacks the thyroid gland. * Iodine Deficiency: Lack of iodine in the diet, necessary for thyroid hormone production. * Surgical Removal: Partial or complete removal of the thyroid gland. * Radiation Therapy: Damage to the thyroid from radiation treatments. * Medications: Certain medications can affect thyroid function

Question 34

What are the symptoms to hypothyroidism?

Answer 34

BMR - decrease in body core temp - decrease in sweating -decrease in thermal discomfort - weight gain - constipation CNS - depression, confusion, poor memory and concentration -growth deficiency -dry skin, hoarse voice, menstrual issues CVS - decrease in HR, MAP

Question 35

What is the treatment to hypothyroidism?

Answer 35

* Thyroid Hormone Replacement Therapy: Synthetic thyroxine (T4) is administered to restore normal hormone levels

Question 36

What are the causes of hyperthyroidism?

Answer 36

*grave's disease *thyroid nodules *thyroiditis *excessive iodine intake *pituitary adenomas

Question 37

What are the symptoms of hyperthyroidism?

Answer 37

BMR - increased body temp increased sweating increased heat intolerance increased appetite weight loss and diarrhoea CNS - anxiety, emotions, restlessness CVS - increase in HR, MAP (palpation)

Question 38

What are some causes for Grave's disease?

Answer 38

*autoimmune mechanism *genetic factors *environmental triggers

Question 39

What are the symptoms of grave's disease?

Answer 39

1.Thyroid-Related Symptoms: * Hyperthyroidism: Symptoms include weight loss, heat intolerance, increased appetite, sweating, and tremors. * Goitre: An enlarged thyroid gland, which may cause a visible swelling in the neck. 2.Ophthalmopathy (Graves' Orbitopathy): * Exophthalmos: Bulging of the eyes due to inflammation and tissue swelling behind the eyes. * Eye Irritation: Dryness, redness, tearing, and sensitivity to light. * Double Vision: Due to swelling and fibrosis of the eye muscles. * Severe Cases: Compression of the optic nerve can lead to vision loss. 3.Cardiovascular Symptoms: * Palpitations, rapid heartbeat (tachycardia), and atrial fibrillation. 4.Neurological Symptoms: * Anxiety, irritability, and tremors. 5.Reproductive Symptoms: * Irregular menstrual cycles or amenorrhoea in females, and erectile dysfunction in males.

Question 40

What are the functions of prolactin?

Answer 40

*stimulation of lactation = milk production and lactogenesis *breast growth and development = mammary gland development and during pregnancy

Question 41

What can high prolactin cause?

Answer 41

* High Levels of Prolactin: Elevated prolactin levels can inhibit the release of Gonadotropin-Releasing Hormone (GnRH) from the hypothalamus. * Effect on Reproductive Function: This inhibition can lead to decreased secretion of luteinising hormone (LH) and follicle-stimulating hormone (FSH), which can cause disruptions in the menstrual cycle in women and reduce fertility in both women and men. Clinical Implications: Conditions causing high prolactin levels, such as prolactinomas (prolactin-secreting pituitary tumours), can lead to symptoms such as amenorrhoea, galactorrhoea (excessive or inappropriate production of milk),and infertility.