Endocrine System Review for ATI-TEAS Exam
Key Concepts
- Homeostasis: Maintained through negative feedback.
- Hormones: Chemical messengers used by the endocrine system; slower but long-lasting effects compared to nervous system.
- Endocrine vs Exocrine Systems: Endocrine deposits hormones directly into the blood, exocrine uses ducts.
- Receptors: Hormones bind to specific receptors, similar to a lock and key mechanism.
Important Glands and Organs
Brain
- Hypothalamus: Control center; links nervous and endocrine systems.
- Pituitary Gland: Consists of anterior and posterior lobes.
- Anterior Pituitary: Receives hormones via blood from hypothalamus.
- Posterior Pituitary: Connects via nerves.
Other Glands
- Thyroid: Around trachea; secretes T3, T4, and calcitonin.
- Parathyroid: Small glands on back of thyroid.
- Thymus: Between sternum and heart; shrinks after puberty.
- Pancreas: Behind stomach; releases insulin and glucagon.
- Kidneys: Includes adrenal glands with cortex and medulla.
- Liver, Gastrointestinal System, Adipose Tissue: Involved in various hormonal functions.
- Gonads: Ovaries in females, testes in males.
Hormones and Pathways
Hypothalamus Hormones
- Thyrotropin Releasing Hormone (TRH): Stimulates TSH release from pituitary.
- Corticotropin Releasing Hormone (CRH): Stimulates ACTH release.
- Growth Hormone Releasing Hormone (GHRH): Stimulates growth hormone release.
- Prolactin Releasing Hormone (PRH): Stimulates prolactin release.
- Gonadotropin Releasing Hormone (GnRH): Stimulates FSH and LH release.
Pituitary Hormones
- Anterior Pituitary:
- TSH: Stimulates thyroid to produce T3, T4, calcitonin.
- ACTH: Influences adrenal cortex (cortisol, aldosterone) and medulla (epinephrine, norepinephrine).
- Growth Hormone: Stimulates growth, maintains bone and muscle mass.
- Prolactin: Stimulates milk production.
- FSH and LH: Involved in reproduction and gonadal functions.
- Posterior Pituitary:
- Oxytocin: Causes milk ejection and uterine contractions.
- Antidiuretic Hormone (ADH): Promotes water retention, increases blood volume and pressure.
Other Hormones
- Pineal Gland: Melatonin, regulates sleep.
- Thymus: Thymosin, stimulates T-cell production.
- Heart: Natriuretic peptides, decrease blood pressure.
- Digestive Tract: Gastrin, secretin, CCK.
- Pancreas: Insulin (decreases blood sugar), glucagon (increases blood sugar).
- Adipose Tissue: Leptin, suppresses appetite.
- Kidneys: Renin (raises blood pressure), erythropoietin (stimulates RBC production), calcitriol (increases intestinal calcium absorption).
Summary
- Reviewed all major glands, hormones, and their roles.
- Prepared for the endocrine portion of the ATI-TEAS exam.
- Understanding pathways and interactions critical for exam success.
Remember to focus on the relationships between hormones and their respective glands/functions for a deeper understanding of the endocrine system!