L19 Ch26 Urinary System Study Review

Flashcards covering the anatomy and physiology of the urinary system, including the structure of the nephron, metabolic waste products, hormone secretion, and urine formation processes.

What are the primary organs of the urinary system responsible for producing urine?

The kidneys (right and left).

What is the function of the Ureters?

They are muscular tubes that transport urine from the kidneys to the urinary bladder.

In males, what secondary substance does the urethra transport besides urine?

Semen.

Which blood vessels specifically supply blood to and carry blood away from the kidneys?

The renal artery and renal vein.

What specific metabolic waste is the primary nitrogenous product of amino acid breakdown in the liver?

Urea.

What is the clinical term for the accumulation of urea in the blood, often indicating poor kidney function?

Uremia.

Which nitrogenous waste is a byproduct of creatine phosphate breakdown in muscles?

Creatinine.

Insoluble crystals of which waste product can cause gout (painful joint inflammation)?

Uric acid.

The kidneys maintain blood pH levels at approximately what value?

$$7.4$$

Which hormone is produced by the kidneys to increase calcium absorption in the small intestine?

Calcitriol (active form of Vitamin $D$).

What hormone do the kidneys secrete in response to low $O_2$ to stimulate red blood cell production?

Erythropoietin ($EPO$).

Which enzyme is secreted by the kidneys in response to low blood pressure to initiate the $RAAS$?

Renin.

What anatomical term describes the location of the kidneys behind the peritoneum?

Retroperitoneal.

Why is the left kidney typically situated slightly superior to the right kidney?

The position of the liver on the right side.

What is the medial indentation where the renal artery, renal vein, and ureter enter or exit the kidney?

The hilum.

What are the triangular or cone-shaped structures found within the renal medulla?

Renal pyramids.

List the sequence of arteries through which blood flows into the kidney, starting from the aorta.

Aorta $\rightarrow$ Renal Artery $\rightarrow$ Segmental Artery $\rightarrow$ Interlobar Arteries $\rightarrow$ Arcuate Arteries $\rightarrow$ Cortical Radiate Arteries.

What vessels supply blood to a single glomerulus?

Afferent arterioles.

What specialized capillaries in the medulla are associated with long nephron loops and urine concentration?

Vasa recta.

What is the structural and functional unit of the kidney?

The nephron.

Approximately how many nephrons are found in a single kidney?

$$\approx 1,000,000$$

What two structures make up the renal corpuscle?

The glomerulus (capillary network) and the Glomerular capsule (Bowman's capsule).

What type of epithelium lines the Glomerular capsule?

Simple squamous epithelium.

Which segment of the renal tubule is the major site of reabsorption for water, ions, and organic nutrients?

The Proximal Convoluted Tubule ($PCT$).

What histological feature of the $PCT$ increases surface area for reabsorption?

A prominent brush border consisting of microvilli.

Describe the permeability of the thin descending limb of the nephron loop.

It is highly permeable to water reabsorption.

Which hormone regulates the final concentration of urine in the collecting ducts?

Antidiuretic hormone ($ADH$).

Where does the process of filtration occur?

In the renal corpuscle.

What are the three main processes involved in urine formation?

Filtration, Reabsorption, and Secretion.

What is the approximate length of the ureters?

$$25-30\,cm$$

What is the triangular region on the posterior-inferior bladder wall where the ureters enter?

The trigone.

Which muscle in the bladder wall contracts to expel urine?

The detrusor muscle.

What is the approximate length of the female urethra?

$$\approx 4\,cm$$

Which urethral sphincter is composed of skeletal muscle and is under voluntary control?

External Urethral Sphincter.

What reflex is triggered by bladder stretch and involves parasympathetic activity to contract the detrusor muscle?

Micturition reflex (urination).

What percentage of functional nephrons may decline between the ages of $25$ and $85$?

$$30-40\%$$

What condition in males involves an enlarged prostate compressing the urethra?

Benign Prostatic Hyperplasia ($BPH$).