1.Why is the Pituitary gland considered the Master gland of the endocrine system? Describe any two disorders of your choice that are caused by pituitary gland dysfunction(1 Point)
2.Compare hormonal vs neural signals. Comment on the need for these differences based on the response time required. Hint: Think about the steroidal vs non-steroidal hormone response to electrochemical signals fired by neurons(1 Point)
3.Give an example of primary hyperthyroid disease. Describe the pathophysiology and manifestations of this disease.(1 Point)
4.Describe the negative feedback loop utilized by the endocrine system with an example of a marathon runner
(1 Point)
5.Why is Diabetic Ketoacidosis (DKA) a more significant problem for Type 1 Diabetes Mellitus than Type 2 Diabetes Mellitus?(1 Point)
6.Explain how treatment of hyperosmolar hyperglycemic syndrome (HHS) with rehydration and insulin can cause serum hypokalemia.(1 Point)
7.In response to hyperglycemia, Protein Kinase C activates VEGF, which over time can lead to retinopathy and retinal detachment. How does this occur?(1 Point)
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The Pituitary gland is considered the Master gland of the endocrine system because it plays a crucial role in regulating and controlling the functions of other endocrine glands in the body. It produces and secretes several hormones that influence various physiological processes, including growth, metabolism, reproduction, and stress response.
Two disorders caused by pituitary gland dysfunction are:
a) Acromegaly: This disorder is characterized by the excessive secretion of growth hormone (GH) by the pituitary gland, usually due to a noncancerous tumor called an adenoma. The excessive GH leads to abnormal growth of tissues and bones, particularly in the hands, feet, and face. Symptoms may include enlarged facial features, enlarged hands and feet, joint pain, thickened skin, snoring, and changes in vision.
b) Hypopituitarism: This condition occurs when the pituitary gland fails to produce one or more of its hormones. It can result from various causes, including tumors, infections, radiation therapy, or autoimmune diseases. The specific hormone deficiencies depend on which part of the pituitary gland is affected. Common manifestations of hypopituitarism include fatigue, weight loss or gain, decreased libido, infertility, menstrual irregularities, low blood pressure, and intolerance to stress.
Hormonal signals and neural signals are two primary modes of communication within the body. The main difference between them lies in the speed of transmission and the target cells they affect.
Hormonal signals: Hormones are chemical messengers secreted by endocrine glands into the bloodstream. They travel throughout the body to reach their target cells, which possess specific receptors for the hormones. The response time for hormonal signals is relatively slower compared to neural signals because it involves transportation through the bloodstream and binding to receptors on target cells. Hormones can have long-lasting effects and regulate processes that require slower, sustained responses, such as growth and metabolism.
Neural signals: Neural signals involve the transmission of electrical impulses along neurons in the nervous system. They are responsible for rapid communication within the body, allowing for quick responses to stimuli. Neural signals travel through specialized pathways, such as nerves, and can target specific cells or organs. The response time for neural signals is much faster compared to hormonal signals since electrical impulses can be transmitted at high speeds.
The differences between hormonal and neural signals are necessary because different physiological processes require different response times. Neural signals provide rapid and immediate responses, which are crucial for reflex actions or responses to acute stimuli. On the other hand, hormonal signals are better suited for long-term regulation, coordinating complex processes, and maintaining homeostasis in the body.
An example of primary hyperthyroid disease is Graves’ disease. Graves’ disease is an autoimmune disorder that causes overactivity of the thyroid gland, resulting in excessive production and release of thyroid hormones (triiodothyronine – T3 and thyroxine – T4).
Pathophysiology: In Graves’ disease, the immune system produces antibodies that stimulate the thyroid gland to produce and release more thyroid hormones. These antibodies bind to the thyroid-stimulating hormone (TSH) receptors on the surface of thyroid cells, activating them and leading to increased synthesis and secretion of thyroid hormones. The excessive production of thyroid hormones disrupts the normal feedback mechanisms that regulate thyroid function.
Manifestations: Graves’ disease is characterized by hyperthyroidism, which leads to various manifestations. These may include weight loss despite increased appetite, heat intolerance, sweating, increased heart rate, palpitations, anxiety, irritability, tremors, fatigue, muscle weakness, goiter (enlarged thyroid gland), eye problems (such as bulging eyes and eye irritation), and in severe cases, a condition called thyroid storm, which is a life-threatening exacerbation of symptoms.
