The Urinary System

What are the 6 functions of the kidneys

*Regulation of blood ionic composition * Regulation of blood pH. *Regulation of blood volume. *Regulation of blood pressure. *Maintenance of blood osmolarity *Production of hormones *Regulation of blood glucose level *Excretion of wastes and foreign substances

What are the FUNCTIONS OF THE URINARY SYSTEM

1. Kidneys regulate blood volume and composition; help regulate blood pressure, pH, and glucose levels; produce two hormones (calcitriol and erythropoietin); and excrete wastes in urine. 2. Ureters transport urine from kidneys to urinary bladder. 3. Urinary bladder stores urine and expels it into urethra. 4. Urethra discharges urine from body.

How long is typical adult kidney?

10-12 cm (4-5 in.) long, 5-7 cm (2-3 in.) wide, and 3 cm (1 in.) thick—about the size of a bar of bath soap

How much plasma that passes through the glomeruli (180 liters) is filtered into the renal tubules daily

20%

What does Excretion of wastes and foreign substances consist of?

By forming urine, the kidneys help excrete wastes—substances that have no useful function in the body. Some wastes excreted in urine result from metabolic reactions in the body. These include ammonia and urea from the deamination of amino acids; bilirubin from the catabolism of hemoglobin; creatinine from the breakdown of creatine phosphate in muscle fibers; and uric acid from the catabolism of nucleic acids. Other wastes excreted in urine are foreign substances from the diet, such as drugs and environmental toxins.

What does Maintenance of blood osmolarity consist of?

By separately regulating loss of water and loss of solutes in the urine, the kidneys maintain a relatively constant blood osmolarity close to 300 milliosmoles per liter (mOsm/liter

What monitors the ECF solute (Na+) concentration

Chemoreceptors in the hypothalamus

3 Basic Renal Functions what are the 3 Basic Renal Functions

Glomerular filtration Tubular reabsorption Tubular secretion

What does Regulation of blood glucose level consist of?

Like the liver, the kidneys can use the amino acid glutamine in gluconeogenesis, the synthesis of new glucose molecules. They can then release glucose into the blood to help maintain a normal blood glucose level.

Describe the renal capsule?

The deep layer..is a smooth, transparent sheet of dense irregular connective tissue that is continuous with the outer coat of the ureter.

nephrons

The filtering unit of the kidney.

What part of the body is responsible for the major work of the urinary system

The kidneys

Why are kidney said to be retroperitoneal?

The kidneys are retroperitoneal because they are posterior to the peritoneum.

What does Regulation of blood pH consist of?

The kidneys excrete a variable amount of hydrogen ions (H+) into the urine and conserve bicarbonate ions (HCO3−), which are an important buffer of H+ in the blood. Both of these activities help regulate blood pH.

What does regulation of blood ionic composition consist of?

The kidneys help regulate the blood levels of several ions, most importantly sodium ions (Na+), potassium ions (K+), calcium ions (Ca2+), chloride ions (Cl−), and phosphate ions (HPO42−).

What does Production of hormones consist of?

The kidneys produce two hormones. Calcitriol, the active form of vitamin D, helps regulate calcium homeostasis (see Figure 18.14), and erythropoietin stimulates the production of red blood cells

Which organs constitute the urinary system?

The kidneys, ureters, urinary bladder, and urethra are the components of the urinary system.

Describe the adipose capsule?

The middle layer, is a mass of fatty tissue surrounding the renal capsule..also protects the kidney from trauma and holds it firmly in place within the abdominal cavity

Describe the renal fascia

The superficial layer. is another thin layer of dense irregular connective tissue that anchors the kidney to the surrounding structures and to the abdominal wall

How does the urinary system contributes to homeostasis

altering blood composition, pH, volume, and pressure; maintaining blood osmolarity; excreting wastes and foreign substances; and producing hormones.

What stimulates ADH secretion from the posterior pituitary gland

an increase in ECF osmolarity

What is Nephroptosis?

an inferior displacement or dropping of the kidney. It occurs when the kidney slips from its normal position because it is not securely held in place by adjacent organs or its covering of fat

Descrube the kidneys?

bean-shaped organs located just above the waist between the peritoneum and the posterior wall of the abdomen.

Where exactly are the kidneys located?

between the levels of the last thoracic and third lumbar vertebrae, a position where they are partially protected by the eleventh and twelfth pairs of ribs

How does blood flow into the kidneys?

by the renal arteries at the concave surface of the kidney that faces medially called the hilus

The distal tubule of up to 8 nephrons drains into a single larger tube called what?

collecting duct

What does Regulation of blood volume consist of?

conserving or eliminating water in the urine. An increase in blood volume increases blood pressure; a decrease in blood volume decreases blood pressure.

Describe the renal medulla?

deep, darker reddish‐brown inner region

Fluid from the ascending limb of the loop of Henle passes into what?

distal tubule

what is The function of the portal system

filter fluid out of the blood and into the lumen of the nephron (occurs at the glomerulus) then to reabsorb the fluid from the tubule back into the blood (occurs at the peritubular capillaries)

parenchyma

functional portion of the kidney

decrease in ECF osmolarity causes what

inhibits ADH secretion from the posterior pituitary gland

nephron twists and folds back on itself so that the final part of the ascending limb of Henle passes between the afferent and efferent arteriole. What is this region called

juxtaglomerular apparatus

what is Tubular reabsorption

moving substances in the filtrate from the lumen of the tubule back into the blood flowing through peritubular capillaries

What are the Three tissue layers of the kidneys?

renal capsule, adipose capsule, renal fascia

What are the two distinct regions of the internal kidneys?

renal cortex & renal medulla

What is the indentation near the center of the concave border called?

renal hilum

Collecting ducts pass from the cortex through the medulla and drain fluid into what?

renal pelvis

Reguarding the Atrial Natriuretic Hormone elevated blood pressure increases venous return which excessively stretches the wall of which atrium

right

Which kidney is lower?

right kidney is slightly lower than the left because the liver occupies considerable space on the right side superior to the kidney

What does Regulation of blood pressure consist of?

secreting the enzyme renin, which activates the renin-angiotensin-aldosterone pathway (see Figure 18.16). Increased renin causes an increase in blood pressure.

what is Tubular secretion

selectively removes molecules from the blood flowing through the peritubular capillaries and adds them to the filtrate in the tubule lumen

Describe the renal cortex?

superficial, light red area

The reabsorption of water and Na+ and the secretion of K+ at the DT and CD can be changed by certain hormones such as Antidiuretic Hormone (ADH), aldosterone, and Atrial Natriuretic Hormone

t

of the plasma that passes through the glomeruli (180 liters) is filtered into the renal tubules daily imbalances in these substances will impact blood pressure, membrane potentials, and cell volume

t

renal blood flow

the blood flow through both kidneys, is about 1200 mL per minute.

what is Glomerular filtration

the movement of fluid from blood into the lumen of the nephron (takes place at the renal corpuscle) the hydrostatic pressure NEVER falls below the osmotic pressure therefore fluid ONLY moves out of the glomerulus into Bowman's capsule (never the opposite

What are the forces governing fluid movement in the renal portal system are similar to?

to those that determine filtration of water and molecules out of systemic capillaries

The modified fluid (urine) leaves each kidney and passes into a hollow tube called what

ureter

The 2 ureters conduct urine from the kidneys to what

urinary bladder