5_Endocrine System II

Page 1: Quiz Instructions

• Complete Quiz 2 on iCollege.

  • Use Lockdown Browser within the first 15 minutes of class.

  • Note: Access to Quiz will disappear after 15 minutes.

• Take time to review Quiz 1

  • Focus on answers you chose in Lockdown Browser.

Page 2: Endocrine System Overview

• Title: Introduction to the Endocrine System

• Visual: A cartoon depiction expressing concern for hormone levels.

Page 3: Commonality Among Individuals

• Question: What do these people have in common?

• Potential exploration of individuals with hormonal imbalances or notable endocrine disorders.

Page 4: Historical Figures and Hormonal Disorders

• Charles Byrne (1761-1783)

  • Height: Estimated 7 ft 7 in

  • Diagnosed with Acromegaly (excess growth hormone).

• Goliath (Biblical Figure)

  • Height: Over 9 ft?

• Discussion: Effects of unbalanced hormones on growth and height.

Page 5: Major Endocrine Structures

• Hypothalamus

  • Regulates control of hormone secretions.

• Pineal Gland

  • Regulation of body rhythms and reproductive maturation.

• Pituitary Gland

  • Anterior pituitary: Hormone secretion for growth, metabolism.

  • Posterior pituitary: Additional functions.

• Kidneys

  • Regulate water and salt balance.

• Thyroid

  • Growth and metabolic rate regulation.

• Adrenal Glands

  • Inner medulla and outer cortex involved in stress response, metabolism.

• Pancreas

  • Regulates sugar metabolism.

• Gonads

  • Maintenance of reproductive organs.

Page 6: Protein Hormones in Hypothalamus

• Key Hormones:

  • Thyrotropin-releasing hormone (TRH): Stimulates TSH production.

  • Growth Hormone-releasing hormone (GHRH): Stimulates GH production.

  • Gonadotropin-releasing hormone (GnRH): Stimulates gonadotropins.

  • Corticotropin-releasing hormone (CRH): Stimulates ACTH release.

  • Growth hormone-inhibiting hormone (GHIH): Inhibits GH.

  • Gonadotropin-inhibitory hormone (GnIH): Inhibits gonadotropins.

Page 7: Other Hormones of Hypothalamus

• Vasopressin (Antidiuretic hormone):

  • Affects water balance.

  • Diabetes insipidus is related to dysregulation.

• Oxytocin:

  • Triggers uterine contractions and milk letdown.

  • Associated with social-related behaviors.

Page 8: Pituitary Gland Structure

• Comprised of two distinct glands:

  • Anterior Pituitary (Adenohypophysis)

  • Posterior Pituitary (Neurohypophysis)

Page 9: Anterior Pituitary Details

• Derived from the roof of the mouth.

• Hormones released from the hypothalamus are transported to this gland to regulate hormone release.

Page 10: Hormonal Interactions in Anterior Pituitary

• Neuroendocrine Cells release:

  • CRH → ACTH → Adrenal Cortex (Stress response).

  • TRH → TSH → Thyroid (Metabolic regulation).

  • GnRH → FSH/LH → Gonads (Reproductive function).

Page 11: Posterior Pituitary Function

• Forms from an outpouching of the brain.

• Hormones are secreted directly from hypothalamic neurons into the bloodstream.

Page 12: Thyroid Gland Overview

• Thyroid hormones developed from tyrosine.

  • Main hormones:

    • Thyroxine (T4)

    • Triiodothyronine (T3)

  • Can cause goiter if levels are imbalanced.

Page 13: Adrenal Glands

• Comprised of two segments:

  • Adrenal Cortex: Produces steroid hormones (corticoids, androgens).

  • Adrenal Medulla: Produces amine hormones (norepinephrine, epinephrine).

  • Responsible for the body's stress response.

Page 14: Cushing's Syndrome Overview

• Description of connection with endocrine disorders.

• Visual representation of affected individuals.

Page 15: Testes Function

• Steroid Hormones: Produced by Leydig cells (androgens).

• Protein Hormones: Produced by Sertoli cells (Mullerian inhibitory hormone during development).

Page 16: Ovaries and Related Structures

• Hormone Production:

  • Steroid Hormones: Estrogens (from theca cells) and Progesterone (from corpus luteum).

• Anatomy of ovaries and their connection to reproduction.

Page 17: Pancreas Hormonal Functions

• Key protein hormones include:

  • Insulin (β cells): Converts glucose to glycogen.

  • Glucagon (α cells): Converts glycogen back to glucose.

  • Somatostatin (δ cells): Regulates insulin and glucagon levels.

Page 18: Pineal Gland Overview

• Produces Melatonin (an amine hormone).

  • Important for regulating biological rhythms associated with light exposure.

Page 19: Stomach Hormones

• Ghrelin: A protein hormone that stimulates appetite.

• Leptin: A protein hormone from fat cells that induces energy expenditure and inhibits appetite.

Page 20: Leptin and Obesity

• Visual comparison of a morbidly obese child before and after treatment with leptin.

  • Implications for weight management and metabolic health.

Page 21: Hormonal Regulation

• Positive Feedback Loop:

  • Exemplified from day 12-14 of the menstrual cycle with GnRH activation.

• Negative Feedback Loop:

  • Predominant throughout the cycle involving FSH, LH, estrogen, and progesterone.

Page 22: Hypothalamo-Pituitary Adrenal (HPA) Axis Regulation

• Overview of CORT in humans (cortisol) and in rodents (corticosterone).

• Key point: Negative feedback plays a significant role in regulation.

Page 23: Hormonal Pathways & Enzymes

• Detailed biochemical pathways related to cholesterol and its derivatives (progestagens, mineralocorticoids, glucocorticoids).

Page 24: Homework Assignment

• Re-read Nelson (2010) for deeper understanding of the Endocrine System.

• Important for upcoming Assignment 4 in-class on Monday.