Urinary System Objectives

Urinary System Functions

Remove nitrogen-based waste

Regulate blood pH, ion balance, water balance

Conduct and Store Urine

What hormones are released by the kidneys?

Erythropoietin and Renin

Erythropoietin Function

Released in response to low blood O2

Stimulates RBC production

Renin Function

Helps increase Blood Pressure

Ureters Location

Retroperitoneal Space

Ureters Relationship to peritoneum

Ureters are behind the peritoneum

Ureters are lined with

 Transitional Epithelium

How Ureter propel urine?

Using Peristalsis

Urinary Bladder Location

Retroperitoneal Space

Urinary Bladder Relationship to Peritoneum

The Urinary Bladder is below the peritoneum

Urinary Bladder is lined with

Transitional Epithelium

How does the Urinary Bladder expand?

Rugae + Transitional Epithelium

Urine is carried into the bladder through

Ureters

Urine is carried out of the bladder through

Urethra

The detrusor muscle in the all of the bladder produces what?

Pressure

Urinary Bladder Function

Stores Urine

Urethra Location

In the pelvic cavity, running from the bladder neck to the external urethral opening

What is the similarity between a female and male urethra?

Both Transitional to Stratified Squamous Epithelial Tissue

What are some differences between a female and male urethra?

Female Urethra:

• Short (4cm)

• Near vaginal orifice and anus 

• Separate from the reproductive tract

Male Urethra 

• Long (20 cm) 

• Overlaps with the reproductive tract 

• Passes through the prostate 

Describe the location of the kidneys relative to other structures

The kidneys are in the abdominal cavity, inferior to the adrenal glands, and lateral to the inferior vena cava and abdominal aorta

How are the kidneys physically supported/held in place?

Perirenal/perinephricic fat + Renal fascia + Paranephritic/pararenal fat

What is the route that fluid takes from the glomerulus to a collecting duct (Five Steps)

• Glomerulus

• Proximal convoluted tubule 

• Loop of Henle

• Distal convoluted tubule 

• Collecting duct

Peritubular Capillaries Function

Provides O2 to tubular cells

Source or secreted materials

Receive reabsorbed materials

How are Peritubular Capillaries different from the Vasa Recta?

Vasa Recta surround the nephron loops of juxtamedullary nephrons, while the Peritubular Capillaries surround the proximal and distal convoluted tubules 

Proximal Convoluted Tubule is lined with

Simple Cuboidal Epithelium

Distal Convoluted Tubule is lined with

Simple Cuboidal Epithelium

Thin Part of the Descending limb is lined with

Simple Squamous Epithelium

Thick Part of Ascending limb is lined with

Simple Cuboidal Epithelium

How does the Proximal Convoluted Tubule relate to the function/activities of each part of the nephron?

It has significant amounts of microvilli to increase its ability to reabsorb material from the filtrate

How does the Distal Convoluted Tubule relate to the function/activities of each part of the nephron?

It is involved in selective reabsorption and secretion in the composition of urine

How does the Thin Part of the Descending limb relate to the function/activities of each part of the nephron?

Highly permeable to water and promotes water reabsorption

How does the Thick Part of the Ascending limb relate to the function/activities of each part of the nephron?

It is Impermeable to water but actively reabsorbs ions

What is Glomerulus?

A network of capillaries in the kidney that filters blood to form filtrate

What vessel carries blood into the glomerulus?

Afferent Arteriole 

What vessel carries blood out of the glomerulus?

Efferent Arteriole

What kind of capillaries are found in the glomerulus?

Fenestrated Capillaries 

What structures make up the filtration membrane which substances pass as they move from the glomerular capillaries to the glomerular capsule?

Glomerular endothelium + Basement membrane + Filtration slits of podocytes

In terms of the size of the afferent and efferent arterioles, explain why blood pressure in the glomerulus is relatively high

Blood pressure in the glomerulus is relatively high because the afferent arteriole is wider than the efferent arteriole

What is the relationship between glomerular blood pressure and the amount of filtrate produced by nephrons?

Higher glomerular blood pressure means there is a larger amount of filtration produced by the nephrons 

What kinds of changes could be made to the afferent and/or efferent arterioles to increase glomerular pressure?

Dilation of the afferent arteriole

Constriction of the efferent arteriole

What kinds of changes could be made to the afferent and/or efferent arterioles to decrease glomerular pressure?

Constriction of the afferent arteriole 

Describe Glomerular Filtration

Water and dissolved solutes exit the blood and enter the nephron due to hydrostatic pressure

Where does Glomerular Filtration take place?

In the Renal Corpuscle

Describe Reabsorption

Solutes and water from the tubule. Move blood by diffusion &/or active transport

Where does Reabsorption take place?

In the Renal Tubule

Describe Secretion

Active transport of solutes from the blood, moves the tubule

Where does Secretion take place?

In the Renal Tubule

What nephron structure is the primary site of reabsorption?

Proximal Convoluted Tubule 

Nephron Loop Function

Promotes water reabsorption 

What are some common materials reabsorbed at the Proximal Convoluted Tubule? (Five Answers)

Water

Ions

Sodium

Glucose

Amino acids

What are some common materials reabsorbed at the Nephron Loop?

Sodium and Chloride (in the ascending limb)

Water (in the descending limb)

What hormones and nephron events increase water reabsorption? (Five Answers)

ADH

Aldosterone

Water follows solutes

Osmosis

Increased permeability

ADH takes place where?

Distal Convoluted Tubule and Collecting Duct

Aldosterone takes place where?

Distal Convoluted Tubule and Collecting Duct

Water follows solutes takes place where?

Proximal Convoluted Tubule

Osmosis takes place where?

Descending limb of the nephron loop

Increased Permeability takes place where?

Distal Convoluted Tubule and Collecting Duct

List all the structures that the filtrate passes through (12 Answers)

• Glomerular/Bowman's capsule

• Proximal convoluted tubule 

• Nephron loop (Loop of Henle) – Descending limb

• Nephron loop – Ascending limb

• Distal convoluted tubule 

• Collecting duct

• Minor calyx

• Major calyx

• Renal pelvis

• Ureter

• Urinary bladder

• Urethra

• Urethral orifice

What is the difference between the Renal Medulla and the Renal Cortex?

Renal Cortex:

• Outer region of the kidney.

• Contains the Renal corpuscles and Proximal & Distal convoluted tubules.

  Renal Medulla:

• Inner region of the kidney.

• Contains the Nephron loops (Loops of Henle) and Collecting ducts

What kidney structures are found in the Renal Medulla?

Loop of Henle (Descending and Ascending limbs),

Renal Pyramids

Vasa Recta

What kidney structures are found in the Renal Cortex? (Five Answers)

• Glomerulus

• Bowman’s capsule

• Proximal convoluted tubule

• Distal convoluted tubule

• Renal corpuscle