Exam 4 (Urinary, Acid/Base, Reproduction)

What are the major excretory organs of the body?

Kidneys, ureters, urinary bladder, and urethra.

What are the functions of the ureters, bladder, urethra, and kidneys.

Kidneys: Form urine.

Ureters: Transport urine to the bladder.

Urinary bladder: Temporarily stores urine.

Urethra: Carries urine out of the body.

What is the renal hilum ?

the indented area where vessels and other structures enter or leave the kidney.

The kidneys are?

Retro peritoneal meaning they lie behind the peritoneum

What are the layers of tissue around the kidney?

Perirenal fat capsule, fibrous capsule, and renal fascia.

what is found in the renal cortex and medulla?

The kidney's internal regions are the renal cortex and renal medulla. About 85% of nephrons are almost entirely in the cortex; juxtamedullary nephrons have long loops of Henle extending deep into the medulla.

What is the structure and function of a nephron?

A nephron is the structural and functional unit of the kidney. Each nephron has a renal corpuscle and a renal tubule. Nephrons are where filtrate is processed and urine is made.

How many nephrons are in each kidney? What happens if one is damaged?

Each kidney has about 1 million nephrons. If a few nephrons do not function, that is okay.

What tissue type is found in Bowman’s capsule and the renal tubule?

Bowman’s capsule is composed of simple squamous epithelium.

What is the most important function of the PCT?

Reabsorption from the filtrate.

What happens in the loop of Henle—descending and ascending limbs?

The descending limb reabsorbs water. The ascending limb reabsorbs sodium.

What is the difference between cortical and juxtamedullary nephrons?

About 85% have short loops of Henle and are cortical nephrons. About 15% have long loops of Henle that extend deep into the medulla and play a major role in producing concentrated urine.

Is pressure in the glomerulus high or low? What happens if it gets too low?

The glomerulus is a high-pressure capillary bed. If pressure is not high enough, no filtrate will form.

What is glomerular filtration, tubular reabsorption, and tubular secretion?

They are the three major renal processes that adjust plasma composition: glomerular filtration, tubular reabsorption, and tubular secretion.

What does ADH do?

ADH causes water reabsorption in the DCT, making the filtrate more concentrated.

What are the general characteristics of urine?

Urine is clear and yellow. Its pH is 4.5–8, with an average pH of 6. Specific gravity is 1.001–1.035. Urine is about 95% water.

What are renal calculi?

Renal calculi are kidney stones. They can be caused by concentrated calcium, magnesium, and phosphate in the renal sinus.

What do the ureters do and how many are there?

There is one ureter for each kidney. Ureters transport urine to the urinary bladder through peristaltic waves caused by smooth muscle in the ureter walls.

What is the function of the bladder?

The urinary bladder is a muscular sac for temporary urine storage.

What tissue is found in the bladder?

The bladder is lined with transitional epithelium and contains smooth muscle called the detrusor muscle.

Where are infections of the bladder most common?

Infections tend to persist in the trigone, the triangular area outlined by the openings for the ureters and urethra.

What is the detrusor muscle?

the smooth muscle in the wall of the urinary bladder.

What do the internal and external urethral sphincters do?

The internal urethral sphincter is involuntary smooth muscle. The external urethral sphincter is voluntary skeletal muscle. During micturition, the internal sphincter opens and the external sphincter relaxes.

What is micturition?

urination

How is the urethra different in males and females?

The female urethra is short, about 3–4 cm (1.5 inches), and is anterior to the vaginal opening. The male urethra is about 20 cm (8 inches), has three named regions, and carries both semen and urine

What are the regions of the male urethra?

Prostatic urethra, membranous urethra, and spongy urethra.

Where in the renal pyramid is concentration the highest?

The osmotic gradient reaches 1200 mOsm at the papilla of the pyramids

What does reproduction involve?

Several processes including formation of the gametes—specialized sex cells (egg and sperm).

What hormones regulate the reproductive system?

Anterior pituitary hormones (gonadotropins—LH and FSH) and sex hormones secreted by the gonads.

What are the sex hormones?

Testosterone, estrogen, and progesterone. They are steroid-based.

What is the function of the male reproductive system?

To produce gametes—sperm cells—and deliver them to the female reproductive tract

What is sperm cell production called?

Spermatogenesis

Where does spermatogenesis take place?

In the seminiferous tubules within the testes.

When does spermatogenesis begin?

At puberty

What happens to the chromosome number during spermatogenesis?

Meiosis reduces the chromosome number from 46 to 23.

How many sperm cells does one undifferentiated sperm cell give rise to?

Four sperm cells

What are the major regions of a sperm cell?

Head, midpiece, and tail.

What is the function of the head of the sperm cell?

It is the genetic region and has an acrosome that helps penetrate the egg.

What is found in the midpiece of the sperm?

Mitochondria

What is the tail of the sperm cell?

A flagellum

What are Sustentacular cells also called?

Sertoli cells or nurse cells

What is the function of Sustentacular cells?

They form the blood-testis barrier and protect sperm from the immune system.