BSC2028 Chapter 26 and 27 study guide

Where are the kidneys located in the body?

retroperitoneal cavity in lower back

just below the ribcage

What endocrine gland sits on top of each kidney?

adrenal glands

What condition can occur is the kidney's suspensory fibers break or become detached?

floating kidney

A prominent medial indentation in the kidney called the ___________ is the entry point for the renal artery and renal nerves and the point of exit for the renal vein and the ureter.

hilum

The kidney has an outer and inner region. What are they called? What does the outer region look like? Which region contains renal pyramids?

outer cortex

inner medulla

the cortex us reddish-brownish and granular

Which vessels deliver blood directly to capillaries supplying individual nephrons?

afferent arterioles

Most of the nerve fibers of the renal nerve are sympathetic postganglionic fibers. List two functions performed by this sympathetic innervation.

(1) adjusts rates of urine formation by changing blood flow at the nephron and (2) influences urine composition by stimulating release of the hormone renin.

The functional units of the kidneys are called ____________. These are the smallest structures that

can carry out all the functions of the system.

nephrons

A cup-shaped chamber that is part of the renal corpuscle is called ___________ or ____________.

glomerular or bowman's capsule

Part of the renal corpuscle is the glomerulus. What is the glomerulus?

A knot of capillaries that projects into the enlarges, proximal end of a nephron; the site of filtration, the first step in the production of urine

Blood leaves the glomerulus via the ____________ arteriole.

efferent arteriole

What type of capillaries are glomerular capillaries?

a specialized bundle of capillaries that are uniquely situated between two resistance vessels

In which part of the nephron does filtration take place?

the glomerulus

In healthy, filtration produces an essentially protein-free solution, known as __________.

filtrate

Inflammation of the glomeruli that impairs filtration by the kidneys is called _____________.

immune complex disorder

Glomerulonephritis is often an immune complex disorder. It may develop after an infection involving which genus of bacteria?

streptococcus bacteria

The main functions of the renal tubule are reabsorption and secretion. When a substance is __________, it is "reclaimed," eventually reentering the blood. When a substance is ________, it

enters the tubular fluid from the blood.

reabsorbed

secreted

What is the primary function of the proximal convoluted tubule (PCT)?

The PCT is responsible for reabsorbing most of the glucose, amino acids, and small peptides that enter the ultrafiltrate

What is the primary function of the distal convoluted tubule (DCT)?

regulating extracellular fluid volume and electrolyte homeostasis.

The juxtaglomerular complex contains a structure called the macula densa. The cells of the macula densa act like what two type of receptors.

juxtaglomerular cells (granular cells), and extraglomerular mesangial cells

Juxtaglomerular cells in the juxtaglomerular complex are modified smooth muscle cells in the wall of the afferent arteriole. These cells function as baroreceptors. What do they monitor?

blood pressure in the afferent arteriole

Juxtaglomerular cells in the juxtaglomerular complex secrete which hormone?

renin

What is the function of intercalated cells of the collecting duct?

regulation of acid-base homeostasis in distal segments of the kidney tubule

There are two types of nephrons in the kidney called cortical nephrons and juxtaglomerular nephrons. What region of the kidney is most of the renal tubule found in cortical nephrons? What region of the kidney is most of the renal tubule found in juxtaglomerular nephrons? [Hint: The two regions of the kidney are the cortex and the medulla. Hint 2: Juxta-: Prefix meaning near, nearby, or close [Use Figure 26-8 The Locations and Structures of Cortical and Juxtamedullary Nephrons for a visual representation of this].

renal cortex

cortical nephron

??

Long, straight capillaries that parallel the juxtaglomerular nephron loop are called the ________.

Vasa Recta

Use Table 26–1 The Organization of the Nephron and Collecting System to answer the following:

What is the primary function of the descending limb of the nephron loop?

Fluid in the descending limb flows toward the renal pelvis

List three important metabolic wastes that are dissolved in the blood

Urea

Creatinine

Uric Acid

List the three distinct processes that form urine in the kidney

filtration

Reabsorption

Secretion

What two transport mechanisms are used during the reabsorption of substances and water in the renal tubule?

active or passive

Just to reiterate: _____________ is the transport of solutes from the peritubular fluid, across the tubular epithelium, and into the tubular fluid.

passive osmosis

Use Table 26–2 Normal Laboratory Values for Solutes in Plasma and Urine to answer the following:

Which four nutrients are not detected or are detected in very small amounts (<0.2 mg/dL) in urine from a healthy adult?

glucose 0.009, Lipids 0.002, Amino Acids 0.188, proteins 0.000

Only solute molecules that are small enough to pass through pores of the filtration membrane in the renal corpuscle end up in the ____________. [Note: to drive this point home, the textbook has a good example of this: Coffee grounds and coffee. Make sure you read that example for a good visual representation of filtration].

filtrate

What is the physical reason why glomerular hydrostatic pressure (GHP) is greater than hydrostatic pressure in typical systemic capillaries?

The main reason that the hydrostatic pressure stays high in the glomerular capillaries is that they don't coalesce into a vein but rather into an arteriole. The efferent arterioles are high-pressure vessels with muscular walls just like the afferent arterioles

What would happen if the glomerular hydrostatic pressure (GHP) and the hydrostatic pressure in typical systemic capillaries were equal? [Hint: What would not be able to happen in the renal corpuscle]?

Before additional filtrate can enter the capsule, some of the filtrate already present must be forced into the PCT. What type of pressure results from the resistance to flow along the nephron and the conducting system. (ie: the force that opposes GHP].

Capsular hydrostatic pressure (CsHP)

The _______________ (NHP) is the difference between the glomerular hydrostatic pressure and the capsular hydrostatic pressure.

net hydrostatic pressure

The blood colloid osmotic pressure (BCOP) is the osmotic pressure resulting from suspended __________ in the blood

proteins

If the glomeruli are damaged by disease or injury, and plasma proteins begin passing into the capsular space, a _________________ (2 words) osmotic pressure is produced. (Note: this pressure is only produced if glomeruli are damaged, thus allowing larger proteins into the filtrate. Therefore, large amounts of protein present in the urine are indicative of kidney damage or disease).

capsular colloid osmotic pressure

The ____________ (NFP) in the glomerulus is the difference between the net hydrostatic pressure and the blood colloid osmotic pressure.

Review Figure 26–10 Glomerular Filtration. This image is a great visual representation of the various pressures that we have just learned

net filtration pressure

The _______________ (GFR) is the amount of filtrate the kidneys produce each minute.

glomerular filtration rate

List three interacting levels of control to ensure that the GFR remains within normal limits:

(1) autoregulation occurring at the local level, (2) hormonal regulation initiated by the kidneys, and (3) autonomic regulation maintained primarily by the sympathetic division of the autonomic nervous system.

Filtration depends on adequate blood flow to the glomerulus and on the maintenance of normal filtration pressures. A mechanism called autonomic regulation is primarily maintained by which division of the autonomic nervous system?

sympathetic division

The GFR is regulated by the hormones of the _____________________________ (RAAS) and the ____________ peptides.

renin- angiotensin-aldosterone system

natriuretic

Renin converts the inactive plasma protein angiotensinogen to _____________.

angiotensin

Inactive angiotensin I is converted to angiotensin II by _______________________ (ACE).

angiotensin-converting enzyme

When a carrier protein is saturated, further increases in substrate concentration have no effect on the rate of transport across the plasma membrane. For any substance, the concentration at saturation is called the ___________ (Tm), or tubular maximum

transport maximum

Define renal threshold.

The point of concentration where a substance cannot be totally reabsorbed and is excreted in the urine

The osmotic concentration, or ____________, of a solution is the total number of solute particles in each liter.

osmolarity

Which part of the renal tubule normally reabsorbs 60-70 percent of the volume of the filtrate produced in the renal corpuscle?

proximal convoluted tubule

List the four main functions of the proximal convoluted tubule (PCT).

Reabsorption of Organic Nutrients

Active Reabsorption of ions

Passive Reabsorption of Ions

Secretion

Which limb of the nephron loop is impermeable to water?

ascending limb

The distal convoluted tubule (DCT) is an important site for what three vital processes?

(1) the active secretion of ions, acids, drugs, and toxins into the tubule; (2) the selective reabsorption of sodium ions and calcium ions from tubular fluid; and (3) the selective reabsorption of water, which assists in concentrating the tubular fluid.

Which part of the nephron loop is responsible for the active secretion of ions, acids, drugs, and toxins into the tubule?

DCT

The collecting system is important in controlling the pH of body fluids through the secretion of which two ions?

hydrogen ions and bicarbonate ions

The exchange of substances between the descending thin limb and the thick ascending limb of the

nephron loop is called ______________ (2 words).

What are the two functions of countercurrent multiplication?

countercurrent multiplier (filtrate flow in the nephron loop) and a countercurrent exchanger (blood flow in the vasa recta)

The concentration gradient created in the peritubular fluid of the medulla is called the _______________ (2 words) gradient.

concentration gradient

medullary osmotic gradient

Without the hormone __________, water is not reabsorbed in the DCT and collecting system, so all the fluid reaching the DCT is lost in the urine. This results in the production of large amounts of very dilute

ADH

Countercurrent exchange occurs at the ____________.

vasa recta

The chemical and physical analysis of a urine sample called a/an ____________ is an important diagnostic tool to determine kidney function.

urinanalysis

_________________ (2 words) is used as an index of overall kidney function. It compares the creatinine level in urine with the creatinine level in blood by estimating the GFR.

creatine clearance

A BUN test measures the amount of urea in blood. What does the acronym BUN stand for?

blood urea nitrogen

What is a pyelogram?

A pyelogram (PĪ-el-ō-gram) is an image of the urinary system (Figure 26-17). It is obtained by taking an x-ray of the kidneys after a radiopaque dye has been administered intravenously.

Urine produced by the kidney is directly emptied in what organ of the urinary system?

The ____________ (2 words) is a hollow, muscular organ that serves as temporary storage for urine.

urinary bladder

What is the function of rugae in the urinary bladder?

the mucosa lining the urinary bladder usually has folds called rugae that disappear as the bladder fills

What muscle is responsible for contraction of the urinary bladder which expels urine into the urethra?

detrusor

Which organ in the urinary system transports urine out of the body?

urethra

Which two spinal reflexes control urination?

Two spinal reflexes control urination (micturition): the urine storage reflex and the urine voiding reflex

The inability to control urination voluntarily is called _____________.

incontienence

Read Clinical Note Urinary Obstruction then answer the following:

What is the common name for renal calculi?

kidney stones

The formation of renal calculi is called ___________.

nephrolithiasis or urolithiasis

List four age-related changes in the urinary system.

- A decrease in the Number of Functional nephrons

- a reduction in the GFR

- A reduced sensitivity to ADH

- Problems with the urinary reflexes

__________ are ions released when inorganic compounds dissociate.

Electrolytes

The ICF has a great proportion of total body ____________ than the ECF.

water

The ECF consists mainly of ____________ fluid and ____________.

interstitial fluid and plasma

ICF consists of

water, dissolved ions, small molecules, and large, water-soluble molecules (such as proteins)

The main ions in the ECF are _________, ___________, and __________.

sodium, chloride, and bicarbonate

The main ions in the ICF are _________, ___________, and __________, but it also contains negatively charged ___________.

potassium, magnesium, and phosphate ions (osate) and negatively charged proteins

All homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the __________, not in the ________.

ecf not in the icf

No receptors directly monitor fluid or electrolyte balance, but instead receptors monitor ___________ volume and ____________ concentration.

____________ hormone is a pituitary hormone that promotes water retention by the kidney.

What are two important effects that occurs when ADH release is increased?

______________ is a corticosteroid hormone that stimulates sodium reabsorption by the kidney, therefore regulating sodium and water balance. (Remember, water follows salt!)

_____________ is secreted in response to an increase in K+, or a decrease of Na+ in blood that reaches the renal cortex. It is also secreted in response to __________________ system activation.

______________ and _______________ are released from cardiac cell walls in response to stretching (ie: increased blood volume).

The release of ___________ peptides reduce thirst and block the release of ADH and aldosterone. This results in ___________, or fluid loss by the kidneys.

What metabolic process generates water within the cells?

The evaporation of water across the epithelium of the skin and lungs is called ____________ perspiration.

The evaporation of water due to secretory activity of the sweat glands is called _____________ perspiration.

The movement of abnormal amounts of water from plasma to the interstitial fluid is called _________.

If the osmotic concentration of the ECF increases, that fluid will become __________ as compared to the ICF.

If the osmotic concentration of the ECF decreases, that fluid will become __________ as compared to the ICF.

When body fluids become increasingly concentrated, sodium ion concentration become abnormally elevated resulting in a condition called _____________.

When body fluids become diluted, sodium ion concentration become abnormally low resulting in a condition called _____________.

The main cation in the ECF is __________ and the main cation in the ICF is ___________.

Problems with ____________ balance are less common, but significantly more dangerous that problems related to ___________ balance

· When the ECF increases in volume, receptors in cardiac muscle cells are stimulated to release _____________ which effect the hypothalamus, kidneys, and blood vessels. ADH and aldosterone release is ________________ resulting in a decrease of ECF volume.

When the ECF decreases in volume, baroreceptors and receptors in the kidney send signals to the hypothalamus, and heart and blood vessel effectors, as well as stimulates the release of renin. In turn ___________ and ____________ are released resulting in an increase in ECF volume.

Aldosterone-sensitive ion pumps reabsorb a ___________ ion from the nephron's tubular fluid in exchange for a ______________ ion in the peritubular fluid.