Kidney Function and Anatomy Quiz

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Questions and Answers

What is one of the primary functions of the kidneys in relation to homeostasis?

Production of red blood cells

Regulation of blood pressure (correct)

Stimulation of metabolic processes

Enhancing digestive enzyme production

Which condition is NOT typically recognized as a cause of kidney disease?

Diabetes

Infection

High cholesterol (correct)

Kidney stones

What is the primary purpose of kidney dialysis?

To provide nutrient absorption

To strengthen kidney tissue

To replicate some functions of the kidneys (correct)

To enhance urine production

Which of the following substances is regulated by the kidneys?

Electrolytes such as sodium and potassium Signup and view all the answers

What is a disadvantage commonly associated with kidney transplants?

The need for lifelong immunosuppressive therapy Signup and view all the answers

Which of the following is NOT a function of the kidneys?

Produce hormones for digestion Signup and view all the answers

What is the outermost layer of protective tissue surrounding the kidneys called?

Renal fascia Signup and view all the answers

The primary functional unit of the kidney is known as what?

Nephron Signup and view all the answers

Which part of the kidney is responsible for the glistening appearance of the organ?

Renal capsule Signup and view all the answers

What is the role of erythropoietin produced by the kidneys?

Stimulate red blood cell production Signup and view all the answers

Which renal region is granular due to the presence of nephrons?

Cortex Signup and view all the answers

Which feature of the kidney refers to the tips of the pyramids pointing toward the renal pelvis?

Renal papillae Signup and view all the answers

What do the renal columns contain that is essential for kidney function?

Blood vessels Signup and view all the answers

What is the primary function of podocytes in the nephron?

Facilitate the filtration process due to their structure Signup and view all the answers

What components make up the renal corpuscle?

Glomerulus and glomerular capsule Signup and view all the answers

Which type of nephron primarily functions within the renal cortex?

Cortical nephrons Signup and view all the answers

What structure leads to the ureter from the renal pelvis?

Major calyces Signup and view all the answers

What type of capillary bed drains blood from the glomerulus?

Efferent arterioles Signup and view all the answers

How many renal pyramids are typically found in one kidney?

Eight Signup and view all the answers

What is the primary role of collecting ducts in the kidney?

Receive urine from multiple nephrons Signup and view all the answers

What is the structure of the renal tubule?

Coiled and hairpin-shaped Signup and view all the answers

What type of nephrons are located near the junction of the cortex and medulla?

Juxtamedullary nephrons Signup and view all the answers

What do the renal major calyces branch into?

Minor calyces Signup and view all the answers

What is the primary role of antidiuretic hormone (ADH) in the kidneys?

Prevent excessive water loss Signup and view all the answers

What happens to blood pH when bicarbonate ions are excreted?

Blood pH increases Signup and view all the answers

Which component of the blood is directly influenced by the movement of water due to changes in electrolyte concentrations?

Blood volume Signup and view all the answers

What is the urine pH range considered normal?

4.5 to 8.0 Signup and view all the answers

What major function do the kidneys serve in maintaining acid-base balance in the body?

Regulating bicarbonate and hydrogen ions Signup and view all the answers

What is the smallest functional unit of the kidney responsible for urine formation?

Nephron Signup and view all the answers

When water intake is excessive, how do the kidneys respond?

Excrete generous amounts of water Signup and view all the answers

How long may it take for the kidneys to alter blood pH levels significantly?

Hours to days Signup and view all the answers

What is the main target of antidiuretic hormone (ADH) within the kidneys?

Collecting ducts Signup and view all the answers

What is the primary function of glomerular filtration?

To filter blood and form urine Signup and view all the answers

What is the glomerular filtration rate (GFR) for a healthy adult?

120-125 ml/min Signup and view all the answers

Which of the following substances is primarily reabsorbed passively in the renal tubules?

Water Signup and view all the answers

What role do peritubular capillaries play in the renal system?

They absorb solutes and water from the renal tubules Signup and view all the answers

Which of the following substances is poorly reabsorbed and found in high concentrations in urine?

Urea Signup and view all the answers

How is urine propelled from the kidneys to the bladder?

By peristalsis Signup and view all the answers

What triggers the reflex contractions of the bladder during micturition?

The activation of nerves when the bladder reaches about 200 ml Signup and view all the answers

What is the primary characteristic of transitional epithelium found in the urinary bladder?

Ability to stretch and recoil Signup and view all the answers

Which sphincter is under voluntary control during micturition?

External urethral sphincter Signup and view all the answers

What is a major function of tubular secretion in the renal system?

To secrete hydrogen and potassium ions Signup and view all the answers

Study Notes

Renal System Overview

The renal system, also known as the urinary system, is responsible for filtering blood and producing urine.
The primary organs of the system are the kidneys.
The kidneys filter waste products from the blood, regulate blood volume, maintain the balance of water and salts, and control the balance between acids and bases.
Kidneys also produce renin, regulate blood pressure and release erythropoietin, and convert vitamin D into its active form.
The system also includes ureters, urinary bladder, and urethra, which are essential for transporting and excreting urine

Intended Learning Outcomes

Describe the location of urinary system organs.
Identify kidney structure.
Describe nephrons.
Describe urine formation.
Understand the role of kidneys in maintaining blood composition.

Kidney Functions

Filter fluid from the bloodstream.
Produce urine containing waste products.
Regulate blood volume.
Maintain the proper balance between water, salts, acids, and bases.
Produce renin regulating blood pressure.
Produce erythropoietin for red blood cell production in bone marrow.
Convert vitamin D into its active form.

Urinary System Structures

Kidneys: Located on either side of the vertebral column; responsible for urine formation and regulation of water balance.
Ureters: Tubes that transport urine from the kidneys to the bladder.
Urinary Bladder: A reservoir that stores urine until it is expelled from the body.
Urethra: Tube that carries urine from the bladder out of the body.

Kidney Internal Anatomy

The kidney has three regions: cortex, medulla, and renal pelvis.
The renal cortex contains nephrons, the functional units of the kidney.
The medulla consists of renal pyramids, which funnel the urine into the renal pelvis.
Renal pyramids and renal columns form the lobes of the kidney.
The renal pelvis leads to the ureters on the outside of the kidney.
Major calyces are extensions of the renal pelvis branching into minor calyces.

Nephron Structure

A nephron is composed of a renal corpuscle and a renal tubule.
Renal Corpuscle: made of glomerulus (knot of capillaries), glomerular capsule (Bowman's capsule).
Renal tubule is a series of convoluted tubes that further process the filtrate.

Podocytes

Podocytes are highly modified cells forming the inner layer of the glomerular capsule.
Their foot processes make the glomerular membrane a "holey" membrane that enables filtration..

Renal Tubule

About 3cm long; beginning at the glomerular capsule, it coils and twists forming a hairpin loop.
The loop, then recoils before entering a collecting duct.

Types of Nephrons

Cortical nephrons: Located almost entirely within the cortex.
Juxtamedullary nephrons: Situated close to the cortex-medulla junction; nephron loops extending deep into the medulla.

Collecting Ducts

Each collects urine from many nephrons.
Runs downward through the medullary pyramids.
Deliver the final urine product into the calyces and renal pelvis.

Blood Supply to Nephrons

Each nephron is associated with two capillary beds: the glomerular capillary bed and the peritubular capillary bed.
Glomerulus is fed by the afferent arteriole and drains through the efferent arteriole.
Blood pressure within glomerular capillaries is higher than other capillaries.
Fluid and small solutes leave the blood into the glomerulus.
Most of the filtrate is returned to the blood by the renal tubule cells.
Peritubular capillaries are adapted for absorption, rather than filtration. Absorb substances like water and solutes from the tubule cells.

Urine Formation (Glomerular Filtration)

Glomerular filtration is a non-selective, passive process.
Fluid filtered from blood into glomerular capsule is called filtrate..
Essentially blood plasma without blood proteins.
Large particles like proteins and blood cells are too large to pass through the filtration membrane.

Glomerular Filtration Rate (GFR)

Average GFR is approximately 120-125ml/min.
GFR is relatively constant.
Can increase if excess body fluid or decrease for fluid conservation.
Is used to check how well kidneys are functioning

Tubular Reabsorption

Waste and excess ions are removed from the filtrate.
Water, glucose, amino acids, and needed ions are reclaimed and transported into the blood.
Process begins as filtrate enters proximal convoluted tubule (PCT).
Water is reabsorbed passively.
Other needed substances reabsorbed actively.
Most reabsorption occurs in PCT

Tubular Secretion

Essentially tubular reabsorption in reverse.
Removal of hydrogen and potassium ions and creatinine.
Helps control blood pH

Nitrogenous Wastes

Nitrogenous wastes include urea, uric acid and creatinine.
Poorly reabsorbed or not at all.
Present in high concentrations in excreted urine

Urine Facts

In 24 hours, about 150-180 liters of blood plasma is filtered in the kidneys.
Healthy individuals produce 1-1.8 liters of urine.
Urine color varies from clear to yellow-due to urochrome.

Abnormal Urine Constituents

Abnormal substances in urine (e.g. glucose, proteins, pus, RBCs, hemoglobin, bile).
Abnormal constituents can occur from various causes; non-pathological and pathological.

Ureters, Urinary Bladder, and Urethra

Ureters: Slender tubes (25-30cm long, 6mm diameter), transport urine from kidneys to bladder via peristalsis.
Urinary Bladder: Smooth, collapsible muscular sac storing urine until release.
Urethra: Thin walled tube carrying urine from bladder to outside the body.
- Internal urethral sphincter, keeps urethra closed; helps with involuntary control.
- External urethral sphincter, keeps urethra closed; important for voluntary control.

Micturition

Process of emptying the bladder.
Controlled by two sphincters; internal and external urethral sphincters.
Bladder collects urine to about 200 ml, and nerves activate reflex contractions to release urine.
When urine collected increases to about 500ml, then reflex starts again.
Voluntary control has no effect eventually.

Maintaining Fluid, Electrolyte, and Acid-Base Balance

Kidneys are crucial for keeping blood composition constant by regulating water, electrolytes, and acid-base balance.
Controlling water balance ensures that we don't lose more water than we take in.
Electrolyte balance prevents water movement from one compartment to another altering blood volume and blood pressure.
Acid-base balance maintains blood pH between 7.35 and 7.45 using various mechanisms.

Regulation of RBC Production

Erythropoietin (EPO) regulates production of mature red blood cells (RBCs) in the bone marrow.
Hypoxia (low oxygen) stimulates EPO production.

Vitamin D

Kidneys convert vitamin D into its active form, 1,25(OH)2D, essential for calcium absorption. Vitamin D is initially created in the skin, travels to the liver and the Kidney to produce its active form.

Kidney Disease

Diabetes, high blood pressure, infection, drugs, and kidney stones can cause kidney disease.
Some kidney failure types can be treated by dialysis, a treatment that replaces the functions of the kidneys.

Kidney Dialysis

Process of removing waste and excess fluid from the blood using an artificial kidney machine.
Blood is collected and filtered through a semi-permeable tube and the waste is removed.
Dialysis is usually done 3 times a week and each treatment lasts about 5 hours.

Kidney Transplantation

Kidney transplant is an option for kidney failure patients.
A donor kidney can either be from a living person or a deceased person (after permission).

Pros and Cons of Kidney Dialysis

Pros: Facilities are widely available, trained professionals are available, and patients can get to know others.
Cons: Treatments are fixed, you must travel to the center, strict diet and fluid limits, and need more medications.

Pros and Cons of Kidney Transplant

Pros: Normal lifestyle (no dialysis), better quality of life.
Cons: Good tissue match needed, expensive operation, risk of transplant rejection, and daily immunosuppressant drugs.

Summary of Renal System Physiology

Nephron is the smallest functional unit of the kidney and performs functions of filtration, resorption, and secretion.
Kidneys help maintain acid-base and fluid balance, regulate electrolytes, eliminate toxins, absorb glucose and amino acids, regulates blood pressure and activate vitamin D (including EPO).

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Description

Test your knowledge on the anatomy and functions of the kidneys with this engaging quiz. Topics cover kidney disease, dialysis, and the various structures that make up the renal system. Perfect for students studying biology or health sciences.