Chapter 17 - Kidneys

What is the role of the kidneys in regulating blood plasma volume?

The kidneys regulate the volume of blood plasma, which affects blood pressure.

How does urine travel from the kidneys to the urinary bladder?

Urine made in the kidney nephrons drains into the renal pelvis, then down the ureter to the urinary bladder.

How does urine exit the body?

passes from the bladder through the urethra to exit the body.

How is urine transported through the ureters?

transported using peristalsis.

What are kidney stones made of?

hard objects formed in the kidneys containing crystallized minerals or waste products.

What is the most common type of kidney stone?

About 80% of kidney stones are calcium stones, but they can also be made of magnesium ammonium phosphate or uric acid.

What increases the tendency to form kidney stones?

a person is dehydrated.

What is lithotripsy?

a treatment where shock waves are used to shatter kidney stones.

What connects smooth muscle cells in the detrusor muscle?

Gap junctions connect smooth muscle cells.

How are detrusor muscles innervated?

by parasympathetic neurons, which release acetylcholine onto muscarinic ACh receptors.

What type of muscle makes up the internal urethral sphincter?

smooth muscle.

What type of muscle makes up the external urethral sphincter?

skeletal muscle.

Where do stretch receptors in the bladder send information?

the S2−S4 regions of the spinal cord.

What does the guarding reflex involve?

inhibition of parasympathetic nerves to the detrusor muscles while stimulating somatic motor neurons to the external urethral sphincter.

What is the function of the guarding reflex?

prevents involuntary emptying of the bladder.

Where does information about bladder stretch pass to?

the spinal cord to the micturition center of the pons.

What does the activation of parasympathetic neurons cause in the voiding reflex?

cause detrusor muscles to contract rhythmically.

What happens when sympathetic innervation of the internal urethral sphincter is inhibited?

causes it to relax.

How does a person control urination?

A person feels the need to urinate and can control when with the external urethral sphincter.

What is stress urinary incontinence?

occurs when urine leakage happens due to increased abdominal pressure, as during sneezing, coughing, and laughing.

What causes stress urinary incontinence in women?

occurs when the pelvic floor no longer provides adequate support to the urethra due to childbirth or aging.

How is stress urinary incontinence treated in women?

a sling surgery, in which inserted mesh provides additional support for the urethra.

What is a common cause of urinary incontinence in men?

occurs as a result of treatments for prostate cancer.

What causes overactive bladder?

uncontrolled contractions of the detrusor muscle that produce a great urge to urinate and the leakage of a large volume of urine.

How is urinary incontinence diagnosed?

by urodynamic testing, which includes cystometric tests where bladder pressure and compliance are measured as the bladder is filled with warm water and the subject is asked to say when the urge to urinate appears.

What is the functional unit of the kidney?

The nephron

What is the process that occurs in the nephron?

Blood is filtered, fluid enters the tubules, is modified, and then leaves the tubules as urine.

What surrounds the glomerulus to form the renal corpuscle?

The glomerular (Bowman’s) capsule surrounds the glomerulus, together making up the renal corpuscle.

After the filtrate is produced in the renal corpuscle, where does it pass into?

into the proximal convoluted tubule.

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