The Urinary System Anatomy and Physiology

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which region of the kidney is located outermost?

Renal cortex (correct)

Renal pyramid

Renal pelvis

Renal medulla

What is the function of the renal pyramids?

To collect urine (correct)

To regulate blood pressure

To produce urine

To filter blood

What is the term for the narrow end of the renal pyramid?

Renal papilla (correct)

Renal column

Renal pelvis

Renal calyx

How many nephrons are found in each kidney?

1 million Signup and view all the answers

What is the term for the capillary beds that reabsorb in the medulla?

Vasa recta Signup and view all the answers

What is the function of the juxtaglomerular apparatus?

To regulate blood pressure Signup and view all the answers

What is the term for the process of forming urine in nephrons and collecting ducts?

Urine formation Signup and view all the answers

What is the term for the cells that produce renin and erythropoietin?

Juxtaglomerular cells Signup and view all the answers

What is the consequence of a low GFR?

Certain waste products may not be adequately excreted Signup and view all the answers

What is one way the body regulates GFR?

By changing the glomerular capillary surface area Signup and view all the answers

What is the effect of constricting the afferent arteriole?

Decreases blood flow into the glomerulus Signup and view all the answers

What system of hormones and enzymes helps control blood pressure?

The renin angiotensin aldosterone system Signup and view all the answers

What is the function of the collecting ducts?

To release urine into the renal pelvis Signup and view all the answers

What is the function of peristalsis in the ureters?

To aid in urine transport Signup and view all the answers

What is the difference in urethral length between males and females?

Males have a longer urethra Signup and view all the answers

What is a unique function of the male urethra?

Is a passageway for sperm cells Signup and view all the answers

What is the main function of the kidneys in regulating blood ionic composition?

Regulating the blood levels of several ions, such as Na+, K+, Ca2+, and Cl- Signup and view all the answers

What is the primary function of the ureters in the urinary system?

To transport urine from the kidneys to the urinary bladder Signup and view all the answers

What is the location of the adrenal glands in relation to the kidneys?

At the top of each kidney Signup and view all the answers

What is the name of the hormone produced by the kidneys that helps regulate calcium homeostasis?

Calcitriol Signup and view all the answers

What is the term for the scientific study of the anatomy, physiology, and pathology of the kidneys?

Nephrology Signup and view all the answers

What is the function of the kidneys in regulating blood volume?

By conserving or eliminating water in the urine Signup and view all the answers

What is the waste product produced by the breakdown of muscle fibers that is excreted by the kidneys?

Creatinine Signup and view all the answers

Where are the kidneys located in the body?

Against the dorsal body wall (retroperitoneal structure) Signup and view all the answers

What is the percentage of glomerular filtrate that returns to the bloodstream via tubular reabsorption?

99-100% Signup and view all the answers

What is the function of the filtration membrane?

To permit the filtration of water and small solutes but prevent the filtration of plasma proteins and blood cells Signup and view all the answers

What is the average glomerular filtration rate (GFR) in males?

125 mL/min Signup and view all the answers

What is the main function of tubular secretion?

To secrete waste materials into the glomerular filtrate Signup and view all the answers

What is the daily volume of glomerular filtrate in adult males?

180 liters Signup and view all the answers

What would happen if the glomerular filtration rate (GFR) is too high?

Needed substances would be lost in the urine Signup and view all the answers

What is the purpose of the glomerular capillaries and podocytes?

To form a leaky barrier for filtration Signup and view all the answers

What is the term for the amount of blood plasma that becomes glomerular filtrate?

Filtration fraction Signup and view all the answers

Study Notes

Urinary System Overview

The urinary system consists of two kidneys, two ureters, one urinary bladder, and one urethra.
The kidneys filter blood plasma, return most water and solutes to the bloodstream, and excrete the remaining waste as urine.

Kidney Functions

Regulation of blood ionic composition (Na+, K+, Ca2+, Cl-)
Regulation of blood pH (H+, HCO3- levels)
Regulation of blood volume (conserving or eliminating water in urine)
Production of hormones:
- Calcitriol (vitamin D) for calcium homeostasis
- Erythropoietin for red blood cell production
- Renin for blood pressure regulation
Excretion of wastes and foreign substances (ammonia, urea, bilirubin, creatinine, uric acid)

Kidney Structure

Located against the dorsal body wall (retroperitoneal structure)
Attached to ureters, renal blood vessels, and nerves at the renal hilum
Composed of:
- Renal cortex (outer region)
- Renal medulla (inner region)
- Renal pelvis (inner collecting tube)
- Renal pyramid and its overlying cortex

Nephron Structure and Function

The structural and functional units of the kidneys (1 million in each kidney)
Responsible for forming urine
Composed of:
- Glomerulus
- Renal tubule
- Glomerular capsule
- Proximal convoluted tubule
- Loop of Henle (descending and ascending limbs)
- Distal convoluted tubule
- Collecting duct

Renal Vasculature

Vascular system:
- Afferent arteriole
- Glomerulus
- Efferent arteriole
- Peritubular capillaries (reabsorption in cortex)
- Vasa recta (reabsorption in medulla)

Glomerular Filtration

The fluid that enters the capsular space is called the glomerular filtrate
Filtration fraction: the amount of blood plasma that becomes glomerular filtrate
Daily volume of glomerular filtrate in adults: 150 liters (females) and 180 liters (males)

Glomerular Filtration Rate (GFR)

The amount of filtrate formed in all renal glomeruli of both kidneys each minute
Average GFR in adults: 125 mL/min (males) and 105 mL/min (females)
Regulated by:
- Blood flow into and out of the glomerulus
- Glomerular capillary surface area available for filtration

Urine Collection and Transport

Collecting ducts release urine into minor calyx → major calyx → renal pelvis → ureter
Ureters: tubes attaching the kidney to the bladder
Urinary bladder: smooth, muscular sac that temporarily stores urine
Urethra: thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis

Urethral Differences between Males and Females

Length: females (3-4 cm) vs. males (20 cm)
Location: females (along the wall of the vagina) vs. males (through the prostate and penis)
Function: females (only carries urine) vs. males (carries urine and sperm cells)

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the anatomy and physiology of the urinary system, including the kidneys, ureters, urinary bladder, and urethra.