Exam 4, Part 1: Urinary System

The urinary functions of elimination occurs through the

Urethra

What is the glomerulus?

a knot of capillaries within the renal corpuscle

What cells line the bladder and uterus

Transitional

What is the most common nephron and where is it

Cortical nephron, found in the cortex

If the CsHP decreases, how is glomerular filtration affected

It increases

vasodilation of afferent arteriole changes the GFR by

Increasing it

The osmolarity of the medullary tissue is _________ than the osmolarity of the cortical tissue

Greater than

The cavity of the kidney that receives urine from the calyces is called the

renal pelvis

Blood leaves the glomerulus through a blood vessel called the

efferent arteriole

The visceral layer in the renal corpuscle is made of specialized cells called

Podocytes

Capillaries that surround the proximal convoluted tubules are

peritubular capillaries

what are the functional units of the kidneys

nephrons

The region known as the macula dense is part of the

distal convoluted tubule

Filtrate first passes from the glomerular capsule to the

proximal convoluted tubule

Most glomeruli are located where in the kidney

Renal cortex

What is the hilum of the kidney?

Where the renal artery rein vein, renal nerves, and ureter enter or exit

What type of tissue surrounds the renal capsule

Adipose tissue

What drains the renal pelvis and prevents back flow towards kidney

ureters

What is the bladder lined with allowing for expansion

Rugae

what is the layer of collagen fibers covering the outer surface of the kidneys

renal capsule

What makes up the trigone in the bladder

2 ureteral openings and the urethra (entrance to bladder at apex)

What muscles in the bladder contract to expel urine

Detrusor muscles

The urethra contains a ______ internal urethral sphincter and a ______ external urethral sphincter

Involuntary, voluntary

layers of the kidney

renal cortex, medulla, pelvis

Blood is delivered to the glomerulus by the _____ arteriole and leaves through the ______ arteriole

afferent, efferent

In the renal corpuscle blood is filtered through

Filtration slits

What are filtration slits?

thin spaces between/separating the pedicels

Where is filtrate formed?

renal corpuscle

What makes up the renal tubules

proximal convoluted tubule, loop of henle, distal convoluted tubule

70% of filtrate reabsorption occurs in the

Proximal convoluted tubule

Tissue Type of Proximal Convoluted Tubule

simple cuboidal epithelium with microvilli

Are the solutes in the descending limb concentrated or diluted

Concentrated because the water leaves

Are the solutes in the ascending limb concentrated or diluted

Diluted because the water stayed

What two hormones regulus the distal convoluted tubule

ADH and aldosterone

What cells make up the juxtaglomerular complex

Macula densa, juxtaglomerular cells, and extraglomerular mesangial cells

What are the epithelial cells of the distal convoluted tubule

Macula densa

What is the collecting system

series of tubes carrying urine away from the nephron

What receives fluid from many nephrons?

collecting ducts

What are the two types of nephrons

cortical and juxtamedullary

What nephron contains peritubular capillaries that connect to the vasa recta

Juxtamedullary nephrons

What is the vasa recta?

long straight capillaries that run parallel to the loop of henle

What is urea?

The most abundant organic waste from the deamination of proteins (ammonia and co2)

What is creatinine?

Metabolic waste 100% eliminated from the system and is from the breakdown of creatinine phosphate

What is uric acid?

A component of kidney stones (insoluble) that is from the breakdown of nucleic acids

Describe the process of filtration

Hydrostatic pressure forces water and solutes out of glomerular capillaries

Describe the process of reabsorption

Absorption of water and solutes from filtrate back into the blood... into peritubular fluid

Describe the process of secretion

Transport of solutes from the peritubular fluid into the filtrate

What is glomerular hydrostatic pressure?

blood pressure in the glomerular capillaries that pushed water and solutes OUT of blood and INTO filtrate

What is capsular hydrostatic pressure?

Pressure that results in the resistance to flow in the nephron and pushes water and solutes OUT of filtrate and INTO blood

What is blood colloid osmotic pressure

Osmotic pressure of plasma proteins in the blood, pushes water and solutes OUT of filtrate and INTO blood

What two pressures oppose glomerular hydrostatic pressure (GHP)

capsular hydrostatic pressure and blood colloid osmotic pressure

What is net filtration pressure (NFP)?

Average pressure forcing water and dissolved substances out of glomerular capillaries and into capsular space

What is the glomerular filtration rate?

the amount of filtrate both kidneys produce in one minute

As NFP increases, GFR and filtration production

increase

As NFP decreases, GFR and filtration production

Decrease

3 levels of control that regulate the GFR

Auto regulation, hormonal regulation and autonomic regulation

What regulation maintains the GFR despite changed in local blood pressure and flow

Auto regulation... involves the changing of luminal diameters

Vasodilation or vasoconstriction in afferent arteriole is an example of what regulation

Local auto regulation

What regulation involved the renin angiotensin aldosterone system (RAAS)

Hormonal regulation

Renin converts _______ to _________.

angiotensinogen to angiotensin I

angiotensin 1 is converted to angiotensin in the

Lungs

The juxtaglomerular complex will release renin if

There is a decrease in blood pressure at the glomerulus

How does angiotensin II affect BP and BV

It increases both

Do natriuretic peptides increase or decrease BP and BV

Decreases both

What peptides helps to increase urine production

Atrial natriuretic peptides

What does sympathetic innervation in autonomic regulation do

Vasoconstriction the glomerular arteriole in a crisis (low BP, heart attack, etc.)

Reabsorption and secretion occur in

Every part of the tubule and collecting systems

Filtrate is similar to blood plasma but does not include what?

Proteins, they are too big

filtrate includes

Metabolic wastes, ions, glucose, amino acids and vitamins

What is facilitated diffusion?

A passive movement where membrane protein lets molecules in WITHOUT energy

What is active transport?

A active movement where membrane proteins USE energy to let the molecules in

What is cotransport?

When two ion types travel in the SAME direction across the same protein

What is counter-transport?

When two ion types travel in OPPOSITE directions across the same protein

In the PCT what is the driving force behind solute transport

Sodium, Na+

What does the counter transport in the PCT involve

Na+ and H+

What is obligatory water reabsorption?

As solutes leave the filtrate, water follows (osmosis)

- water movement that cannot be prevented

The descending limb is permeable to _____ but not to _____

Water, solutes

The ascending limb is impermeable to ______

Water

The ascending limb passively and actively removes ____ and _____ ions from filtrate

Na+ and Cl-

What is the tissue type in the descending limb/loop of henle

Squamous cells with no microvilli or mitochondria

What coats the inside of the ascending limb of henle and what does it do

Glycoprotein, restricts water reabsorption

The ascending limb of henle moves what from filtrate INTO cuboidal cells during cotransport

Na+, K+, and Cl-

The ascending limb of henle moves what OUT of cuboidal cells curing cotransport

K+ and Cl-

In the ascending loop what moves out and what moves in at the basolateral membrane during counter transport

Na+ out and K+ in

2/3 of the osmolarity is due to _____ and 1/3 is due to _____

Solutes (sodium and chloride) and urea

High osmolarity means _____ water and ____ solute concentration

Little, high

Low osmolarity means _____ water and ____ solute concentration

Lots, low

Will an increase in solute concentration in the DLH will ____ solute pumping in the ALH

Accelerate

What hormone is involved in an increase in NA reabsorption and K secretion

Aldosterone

What is facultative water reabsorption

Volume of water reabsorbed along DCT, collecting system

facultative water reabsorption it is relatively impermeable to water except in the presence of what

ADH, antidiuretic hormone

What delivers oxygen and nutrients to the medullary tissue

The vasa recta

Blood flow in the vasa recta moves _______ to filtrate flow

Opposite

When the VR blood flows down towards the medulla what happens

Sodium and chloride move into the blood and water follows (high osmolarity)

When the VR blood flows up towards the cortex what happens

No more sodium or chloride enter but more water moves into the blood (high osmolarity)

filtration occurs exclusively in the

renal corpuscle

water reabsorption occurs primarily along the

PCT and descending limb

The ALH and the DCT are _________ to urea

Impermeable

Papillary ducts are _________ to urea

permeable

What nephron produces more concentrated urine?

juxtamedullary