Urinary System Anatomy and Physiology: Water, Solutes, and Hormonal Regulation

What are the main components of the urinary system?

Pair of kidneys, pair of ureters, urinary bladder, and urethra.

What is the primary function of the kidneys?

Urine production, blood filtration, acid-base regulation, hormone production, and blood pressure regulation.

What is the functional unit of the kidney?

The nephron.

What is produced in the renal corpuscle?

Glomerular filtrate.

How does increased blood pressure affect filtration in the kidneys?

Increased blood pressure leads to increased filtration.

What is the role of the proximal convoluted tubule?

Reabsorption and secretion of water, ions, glucose, and amino acids.

What is the function of the Loop of Henle?

Exchange of water and ions; it descends into the medulla and returns to the cortex.

What is the role of the distal convoluted tubule?

Helps maintain electrolyte homeostasis.

What does the collecting duct do?

Facilitates electrolyte exchange, acid-base balance, and water reabsorption.

What hormone is produced when the kidneys sense a drop in blood pressure?

Angiotensin II.

What is the effect of aldosterone on the kidneys?

Increases sodium reabsorption at the collecting duct and distal convoluted tubule.

What is the role of ADH in kidney function?

Increases water permeability at the collecting duct and distal convoluted tubule.

What is tubular reabsorption?

The process of reclaiming water and solutes from the filtrate back into the blood.

What substances are typically secreted during tubular secretion?

H+, K+, ammonia, urea, and medications.

How do kidneys maintain acid-base balance?

By reabsorbing bicarbonate (HCO3-) and secreting hydrogen ions (H+).

What type of muscle is involved in the peristalsis of the ureters?

Smooth muscle.

What triggers the spinal reflex arc for micturition?

Stretch receptors in the detrusor muscle when the bladder is full.

What is the difference between the urethra in males and females?

The female urethra is shorter, wider, and straighter, while the male urethra is longer, narrower, and curved.

What is the external opening of the urethra called?

Urinary meatus or external urethral orifice.

What type of epithelium lines the urinary bladder?

Transitional epithelium.

What is the role of the detrusor muscle?

It contracts to facilitate urination.

What are the two types of muscle in the external urethral sphincter?

Smooth muscle (internal sphincter) and striated muscle (external sphincter).

What is the renal threshold?

The limit to reabsorption by the kidney.

What is the primary method of water loss in the body?

Urination.

What are the two types of water gains in the body?

Absorption by the GI tract and metabolism.