general introduction excretory organs lungs liver skin kidneys
TRANSCRIPT
General Introduction
Excretory Organs
Lungs
Liver
Skin
Kidneys
Functions of the Urinary System
A. Conserves Valuable NutrientsB. Separates/Eliminates WastesC. Regulates Blood Volume and Blood PressureD. Regulates Ion Levels In PlasmaE. Regulates Blood pH
Organs of the Urinary System
• Kidneys
• Ureters
• Urinary bladder
• Urethra
Kidneys: Location
Retroperitoneal
Kidneys: StructureRenal capsule
Several layers of fat
Kidneys: Structure
2 layers:
Cortex
Medulla
Kidneys: Structure
Calyx
Renal Pelvis
Renal Hilus
Nephron
• Glomerulus
• Bowman’s capsule
• Proximal convoluted tubule
• Loop of Henle
• Distal convoluted tubule
Glomerulus and Bowman’s Capsule
Bowman’s Capsule
Podocytes
Pedicels
Filtration Slits
Collecting Duct
Summary of Flow of FluidGlomerular capsuleProximal convoluted tubuleLoop of HenleDistal convoluted tubuleCollecting ductRenal papillaCalyxRenal pelvisUreterBladderUrethraOut of body
Kidneys: Function
Filter wastes and produce urine by:
• Filtration• Reabsorption• Secretion
Ureters: Structure•Mucosa: epithelium
•Muscularis: two layers
•Adventitia: connective tissue
a = lumenb= mucosac = circular muscle layerd = longitudinal muscle layere = adventitia
Ureters: Structure
Ureters: Function
Carry urine from the kidneys to the urinary bladder
Urinary Bladder: Structure
Mucosa (rugae)
Muscularis (Detrusor muscle)
Adventitia
Urinary Bladder: Function
Stores and expels urine
Urethra: Structure
Mucosa
Muscularis
Adventitia
Urethra: Function
Transports urine from bladder to outside body
Female Urethra
Male UrethraProstatic Membranous Spongy/Penile
Blood Flow Through the Kidney (A RAGE PRV I)
•Abdominal Aorta
•Renal Artery
•Afferent Arterioles
•Glomerular
Capillaries
•Efferent Arterioles
•Peritubular
Capillaries
•Vasa Recta
•Renal Vein
•Inferior Vena Cava
Tubular Section of Nephron
Figure 23.4b
Regulation of Water and Electrolytes
The body gains water through 2 processes
1. Absorption
2. Metabolism
Water Loss
• Urinary System
• Lungs
• Skin
• Intestines
Cardiac Output and Renal Function
Cardiac Output =
Stroke volume (ml) Heart Rate (beats/min)
Hormones that Regulate Electrolyte Balance
• Antidiuretic Hormone (ADH or vasopressin)
• Renal-Angiotensin Aldosterone
• Erythropoetin
• Atrial Natriuretic Hormone
Antidiuretic Hormone (ADH)
Released in response to increase in concentration of electrolytes in blood or a fall in blood volume or pressure
ADH decreases the amount of water lost at the kidneys, which reduces the concentration of electrolytes.
ADH also constricts peripheral blood vessels, which helps to increase blood pressure.
Renin-Angiotensin-Aldosterone
• The enzyme renin is released by kidney in response to a decrease in blood volume, blood pressure or both.
• Renin starts chain of reactions that lead to formation of hormone in liver called angiotensin II.
• AG II stimulates adrenal cortex to make aldosterone and posterior pituitary gland to make ADH.
• Both inhibit salt and water loss at kidneys resulting in increased blood volume and blood pressure.
Erthyropoietin
• Released by kidneys in response to low O2 levels
• Stimulates production of RBCs in bone marrow.
• Increase number of RBCs elevates blood volume.
Atrial Natriuretic Hormone
• Cells in right atrium make this hormone in response to increased blood volume.
• Stimulates loss of sodium ions and water at the kidneys
• Inhibits renin release
• Inhibits secretion of ADH and aldosterone
• Result is reduced blood volume and blood pressure.