Chapter 15 The Urinary System
 Functions of the Urinary System
 Elimination of:
 ______________________
 Nitrogenous wastes
 ___________________
 Drugs
 Functions of the Urinary System
 Regulate aspects of homeostasis
 ___________________ balance
 Electrolytes
 Acid-base balance in the blood
 ___________________
 Red blood cell production
 Activation of vitamin D
 Organs of the Urinary system
 Kidneys
 ________________
 Urinary bladder
 _________________
 Location of the Kidneys
 Against the ________________ body wall
 At the level of T12 to L3
 The right kidney is slightly ______ than the left
 Attached to ureters, renal blood vessels, and
nerves at renal hilus
 Atop each kidney is an ______________ gland
 Coverings of the Kidneys
 _______________ capsule
 Surrounds each kidney
 ________________ capsule
 Surrounds the kidney
 Provides protection to the kidney
 Helps keep the kidney in its correct
location
 Regions of the Kidney
 Renal cortex – ________________ region
 Renal medulla – inside the cortex
 Renal pelvis – inner _______________ tube
 Kidney Structures
 Medullary pyramids – ______________ regions of tissue in the medulla
 Renal ________________ – extensions of cortex-like material inward
 ________________ – cup-shaped structures that funnel urine towards the renal pelvis
 Blood Flow in the
Kidneys
15.1.3 - Recognize
that the nephron is
the structural and functional unit of the kidney and describe its
anatomy.
Nephrons
 The structural and ____________________ units of the kidneys
 Responsible for forming ____________________
 Main structures of the nephrons
 ____________________
 Renal tubule
 Glomerular capsule (Bowman’s capsule) - The closed end of the
____________________ is enlarged and cup-shaped and completely
surrounds the glomerulus.
Glomerulus
 A specialized ____________________ bed
 Attached to arterioles on both sides (maintains high pressure)
 ____________________ afferent arteriole
 Narrow efferent arteriole
Glomerulus
 Capillaries are covered with ____________________ from the renal tubule
 Podocytes form a porous, membrane around the glomerulus
 The glomerulus sits ____________________ a glomerular capsule (the first part of the renal tubule)
Renal Tubule
 Glomerular (Bowman’s) capsule
 Proximal convoluted tubule
 Loop of ____________________
 Distal convoluted tubule
Types of Nephrons
 Cortical nephrons
 Located entirely in the ____________________
 Includes most nephrons
 Juxtamedullary nephrons
 Found at the ____________________ of the cortex and
medulla
Glomerulus Capillaries
 Each nephron is associated with ____________________
capillary beds, glomerulus and peritubular.
 Glomerulus
 Unlike any other capillary in the body
 Fed and ____________________ by arterioles
 High-resistance vessels
 Blood pressure is very ____________________
 High Pressure
 Forces fluid and solutes out of blood
 ____________________ is reclaimed and returned to blood
Peritubular Capillaries





Arise from ____________________ arteriole of the glomerulus
Normal, ____________________ pressure capillaries
Attached to a venule
Cling close to the renal tubule
Reabsorb (reclaim) some substances from ____________________ tubes
15.1.4 - Describe the process of urine formation, identifying the areas of the nephron that are
responsible for filtration, reabsorption, and secretion.
 Urine Formation Processes
 ____________________
 Reabsorption
 Secretion
Filtration
 Nonselective ____________________ process
 Water and solutes smaller than proteins are forced through ____________________ walls
 Blood cells cannot pass out to the capillaries
 Filtrate is collected in the glomerular capsule and leaves via the renal tubule
Reabsorption
 The peritubular capillaries reabsorb several materials
 Some water
 ____________________
 Amino acids
 Ions (ex _____________________________ )
 Some reabsorption is passive, most is active
 Most reabsorption occurs in the proximal convoluted
tubule
Materials Not Reabsorbed
 Nitrogenous waste products
 Urea
 ____________________
 Creatinine
 Excess water
Secretion – Reabsorption in Reverse
 Some materials move from the peritubular capillaries
into the renal tubules
 ____________________ and potassium ions
 Creatinine
 Materials left in the renal tubule move toward the ____________________
15.1.8 Describe the composition of normal urine.
 Characteristics of Urine Used for Medical Diagnosis
 Colored somewhat yellow due to the pigment urochrome (from the destruction of ________________)
and solutes
 _________________
 Slightly aromatic
 Normal pH of around ______________
 Specific gravity of 1.001 to 1.035
15.2.1 - Describe the general structure and function of the ureters, urinary bladder, and urethra.
Ureters
 Slender tubes attaching the kidney to the ______________
 Continuous with the renal _____________
 Enter the posterior aspect of the bladder
 Runs behind the peritoneum
 _______________ aids gravity in urine transport
Urinary Bladder
 ________________ , collapsible, muscular sac
 Temporarily stores urine
 ____________ – three openings
 Triangular passageway
 Very sensitive to _________
 Two from the ureters
 One to the urethrea
 Urinary Bladder Wall
 ____________ layers of smooth muscle (detrusor muscle)
 Mucosa made of transitional epithelium
 Walls are thick and folded in an empty bladder
 Bladder can expand significantly without increasing internal _______________
 Urethra
 Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis
 Release of urine is controlled by two _______________
 Internal urethral sphincter (involuntary)
 External urethral sphincter ( ________________ )
15.2.2 - Compare the course and length of the male urethra to that of the female.
Urethra Gender Differences
 Length
 ____________ – 3–4 cm (1 inch)
 Males – 20 cm (8 inches)
 Location
 Females – along _________ of the vagina
 Males – through the ____________ and penis
 Function
 Females – only carries urine
 Males – carries urine and is a passageway for _____________ cells
 Micturition (Voiding)
 __________ sphincter muscles must open to allow voiding
 The internal urethral sphincter is relaxed after __________ of the bladder
 Activation is from an impulse sent to the ______________ and then back via the pelvic splanchnic
nerves
 The external urethral sphincter must be voluntarily ____________