Endocrine System Quiz

Prayer Before Class

• A prayer is used before class, asking for guidance and wisdom.
• The prayer is directed to the Holy Spirit, seeking enlightenment and removing the darkness of sin and ignorance.
• It requests a penetrating mind, a strong memory, and the ability to comprehend and express oneself effectively.
• It also asks for the successful completion of the work to come.
• The prayer concludes with a request for guidance through Jesus Christ, and ends with a statement of the belief in God, and the Father, for eternity, and an amen.

Course Content: Anatomy and Physiology with Pathophysiology

• Endocrine System Physiology: This section covers principles of chemical communication, characteristics of hormones, functions of hormones, anatomy of endocrine glands, and diseases within the endocrine system relevant to the Philippines. Also included are diagnostic tests for Endocrine Disorders relevant to Medical Technologists

Unit Intended Learning Outcomes

• Students must describe the general functions of the endocrine system.
• Students must integrate understanding of the endocrine system's physiology with the pathophysiology of common diseases and conditions.

Formative Assessment Questions

• Question 1: Defines a chemical messenger that travels through the bloodstream to a target tissue, initiating coordinated responses. (This is a definition of a hormone)
• Question 2: Asks for three endocrine glands.
• Question 3: Requires three examples of hormones, their respective glands and functions

Overview of the Endocrine System

• The endocrine system comprises glands and specialized cells secreting chemical messengers (hormones).
• Hormones are delivered into the bloodstream, regulating homeostasis.

Endocrine vs Exocrine

• Endocrine: Hormones diffuse into the bloodstream to be transported to target tissues. Examples include growth hormone, thyroid hormone, oxytocin, and estrogen.
• Exocrine: Secretions are carried through ducts to the outside of the body or into a bodily cavity. Examples: saliva (salivary gland) and sweat (sweat glands)

Chemical Nature of Hormones

• Water-soluble: Free hormones dissolve directly into the plasma, have short half-lives, and are rapidly broken down by enzymes.
• Lipid-soluble: Travel in the bloodstream bound to binding proteins.

Control of Hormone Secretion

• Humoral: Blood levels of substances directly influence hormone release. (For instance: Blood calcium levels)
• Neural: Neurons stimulate hormone release through neurotransmitters. (Stress or exercise)
• Hormonal: Hormones stimulate (or inhibit) the release of other hormones. (Tropic hormones)

Regulation of Hormone Levels

• Negative feedback: Hormone secretion is inhibited by itself once blood levels reach a target point, ensuring homeostasis.
• Positive feedback: A hormone stimulates the synthesis and secretion of another hormone, creating a self-sustaining cycle.

Endocrine Glands & Their Hormones

• Pituitary Gland: Anterior: growth hormone, ACTH, LH, TSH; Posterior: antidiuretic hormone, oxytocin.
• Pancreas: Alpha cells – glucagon; Beta cells – insulin; Delta cells – somatostatin.
• Reproductive system: Ovaries – progesterone, estrogen; Testes – testosterone.
• Thyroid Gland: T₃ (triiodothyronine), T₄ (thyroxine), and calcitonin.
• Parathyroid Gland: Parathyroid hormone (PTH).
• Adrenal Glands: Medulla – epinephrine; cortex – aldosterone, cortisol, androgens.
• Pineal Gland: Melatonin and arginine vasotocin.

Functions of the Endocrine System

• Regulate metabolism, food intake and digestion
• Involved in tissue development
• Regulate ion levels
• Control of water balance
• Blood pressure, blood glucose levels
• Reproductive functions
• Stimulation of uterine contractions, milk release
• Modulation of immune system function

Pituitary Gland: Anatomy and Function

• The pituitary gland is connected to the base of the brain.
• It has two lobes: posterior (neurohypophysis) and anterior (adenohypophysis), structurally and functionally connected to the hypothalamus.

Pituitary Gland & Hypothalamus

• The pituitary gland and hypothalamus both play major roles in regulating the body's endocrine functions, with the hypothalamus influencing the pituitary gland. The hypothalamus regulates the pituitary's secretory activity in response to stimuli.

Hormones of the Hypothalamus

• Hormones of the hypothalamus influence multiple bodily functions. Numerous hormones are designed for the stimulation or inhibition of hormone secretion by the anterior pituitary gland.

Posterior Pituitary Gland: Hormones (ADH and Oxytocin)

• ADH (Antidiuretic Hormone/Vasopressin) plays a crucial role in water balance, controlling urine output, constricting blood vessels, and raising blood pressure. Target tissues include the kidneys and blood vessels.
• Oxytocin: Stimulates smooth muscle contraction, particularly involved in uterine contractions during labor and milk ejection. Target tissues include uterus and mammary glands.

Anterior Pituitary Gland: (Growth Hormone, PRL, TSH, ACTH, Others)

• Growth Hormone: Essential for growth and development of most tissues in the body; affects protein synthesis. Target tissues are generally all tissues in the body.
• Prolactin: Stimulates milk production in lactating females; its function in males is less well understood. Target tissue: Mammary glands.
• TSH (Thyroid Stimulating Hormone) stimulates the thyroid gland. Target tissue: Thyroid gland.
• ACTH (Adrenocorticotropic Hormone) stimulates the adrenal cortex, impacting cortisol secretion. Target tissue: Adrenal cortex.

Thyroid Gland

• The thyroid gland, alongside the parathyroid gland, regulates various bodily functions with hormones like T3 and T4, and calcitonin.

Thyroid Gland: T3 and T4 & Calcitonin

• T₃ and T₄: Essential for growth, maturation, and general metabolism. They increase metabolic rate and protein synthesis. Most cells of the body are target tissues.
• Calcitonin: Decreases blood calcium levels by inhibiting the activity of osteoclasts (cells that break down bone). Target tissue: Bone.

Thyroid gland: Iodine Deficiency and Hyperthyroidism

• Iodine deficiency causes an enlargement of the thyroid gland and can result in hypothyroidism. TSH secretion increases in an attempt to stimulate inadequate T3 and T4 production.
• Hyperthyroidism conditions, including Graves' disease, result in excessive thyroid hormone production due to various factors.

Effects of T₃ and T₄

• Elevated levels of T3 and T4 increase metabolic rate, body temperature, and have impacts on growth and nervous system development. Declining levels result in the opposite effects.

Adrenal Gland

• The adrenal glands are located above the kidneys and have two parts: the cortex (which regulates mineralocorticoids, glucocorticoids, and androgens) and the medulla (which regulates epinephrine).

Adrenal Medulla: Epinephrine

• Epinephrine, also known as adrenaline, is involved in the body's response to physical activity, increasing cardiac output, blood flow to muscles, and carbohydrate and lipid metabolism. Target tissues are varied throughout the body.

Adrenal Cortex

• Mineralocorticoids (Aldosterone): Regulate sodium and water balance, impacting blood pressure. Target tissue: Kidneys
• Glucocorticoids (Cortisol): Control carbohydrate, protein, and fat metabolism; regulate blood glucose levels, and influence inflammatory and immune responses. Target tissues: Peripheral tissues like skeletal muscle, liver, adipose tissue and immune system.
• Androgens: Support the development and maintenance of secondary sex characteristics in males. Target tissue: Peripheral tissues.

The Pancreas

• The pancreas is a crucial gland containing both exocrine (which produces digestive enzymes) and endocrine (which regulates blood sugar with insulin and glucagon) functions.

Pancreas: Insulin

• Insulin is secreted in response to elevated blood glucose, stimulating glucose transport into body cells and its subsequent storage as glycogen.

Pancreas: Glucagon

• Glucagon counters the effects of insulin, promoting glucose release from cellular stores when blood glucose levels decline.

Diabetes Mellitus (T2DM)

• Diabetes mellitus type 2 is defined by a gradual failure of cells to respond to insulin and use glucose properly. There a variety of potential causes, including genetics or lifestyles.

Pineal Gland

• The pineal gland regulates reproductive functions and other hormonal activity by being regulated by photoperiod (light/dark cycles) with melatonin being one of its most important hormones. Melatonin, together with arginine vasotocin, controls the reproductive system.

Disclaimers: These notes are intended for educational purposes only and do not constitute medical advice. Always consult with a healthcare professional for any health concerns or before making any decisions related to your health or treatment. This summary is based solely on the provided images and should not be considered exhaustive or definitive on every point.