Post on 31-May-2015
Chapter 14
Chapter 14 – The Urinary System
Applied Learning Outcomes
Use the terminology associated with the urinary system
Learn about the following:• Organs and structures of the
urinary system• Physiology of the urinary systemUnderstand the aging and pathology
of the urinary system
Overview
Chapter 14 – The Urinary System
The urinary system plays a major role in in the removal of wastes to maintain homeostasis. It acts as a filtering system of the blood. It not only removes wastes, it maintains the pH level, electrolyte composition, and water content of the blood.
Gross Anatomy of the Urinary System
Chapter 14 – The Urinary System
Urine Voiding
Chapter 14 – The Urinary System
Micturition (urination) involves both reflexive and voluntary control.
The detrusor muscles of the bladder respond to pressure in the bladder by contracting and forcing urine into the opening of the internal urethral sphincter.
The sphincter relaxes and allows urine to exit the bladder. It flows through the urethra to the body’s exterior.
The Nephrons
Chapter 14 – The Urinary System
• Perform all of the physiological functions of the urine formation
• Composed of an integral complex of blood vessels and renal tubules
Urine Formation
Chapter 14 – The Urinary System
Urine is formed in three stages:
• Glomerular filtration
• Tubular reabsorption
• Tubular secretion
Hormonal Regulation of Urine Formation
Chapter 14 – The Urinary System
Antidiuretic hormone (ADH) reduces diuresis, or water excretion, and helps to prevent dehydration.
Atrial natriuretic factor (ANF) is produced by special cardia cells; its purpose is to lower blood pressure by reducing blood volume through increased diuresis.
Angiotensis II elevates blood pressure through vasoconstriction; the consequent increase in pressure within the glomerular capillaries increases filtration and elevates urine output.
Wellness and Illness over the Life Span
Chapter 14 – The Urinary System
Most urinary system disorders involve malfunction of the renal system, while others involve the structures of the conducting system.
Urinary disorders are categorized as the following: congenital, infection/inflammation, immune, hormonal, degenerative, tumor.
Health conditions are major contributors to any age-related decrease in urinary function.
Summary
The urinary system removes waste to maintain homeostasis, acts as a filtering system of the blood, and maintains the pH level, electrolyte composition, and water content of the blood.
All organs and structures of the urinary system can be invaded by bacteria, resulting in infection and inflammation.
Components of the urinary system involved in proper urine voiding are more likely to be affected by the aging process.
Chapter 14 – The Urinary System