Quiz #8 Flashcards
The kidneys help maintain homeostasis throughout the
body by performing the following functions:
o Regulation of ion levels in the blood
o Regulation of blood volume and blood pressure
o Regulation of blood pH
o Production of hormones
what does the urinary system consist of
- two kidneys
- two ureters
- one urinary bladder
- one urethra
Examples of wastes that are toxic if high enough levels are in the blood include:
urea, creatinine, and
ammonia
Wastes are eliminated from the body by:
Urinary system (urea, creatinine, ammonia)
* Large bowel (feces)
* Lungs (carbon dioxide)
* Skin (excess water and salts, small amount of urea)
Kidney Location and Appearance
Sits between the 12th thoracic and 3rd lumbar vertebrae
Reddish-brown color
Bean-shaped
About 12 cm long
Wrapped in a tough, fibrous capsule 🫘
Internal Kidney Regions
Renal Cortex
Renal Medulla
Special Areas
Hilum
Area where blood vessels, nerves, and ureter enter/exit the kidney
Kidney functions
Blood Volume Regulation
Electrolyte Management
pH Balance
Tissue Fluid Regulation
Blood Volume Regulation:
- Control how much water stays or leaves the body
- Adjust blood pressure 💧
Internally, the kidneys consist of:
a renal cortex
renal medulla,
renal pyramids
renal columns
and major and minor calyces that
drain into the renal pelvis.
Small renal papillae project into each minor calyx
where does blood enter and leave the kidney
Blood enters the kidney through the renal artery and leaves
through the renal vein
Renal Cortex:
- Outer layer
- Contains the nephrons (tiny filtering units) 🔬
Renal Medulla:
-Inner region
- Houses tubes leading to kidney tips (papillae) 🧪
Blood Volume Regulation:
- Control how much water stays or leaves the body
- Adjust blood pressure 💧
Special Areas:
Renal Pyramids
Renal Columns
Major and Minor Calyce
Electrolyte Management:
-Balance mineral levels in blood
Keep ions just right
pH Balance
-Control blood acidity/alkalinity
-Manage hydrogen and bicarbonate ions 🧪
Tissue Fluid Regulation:
- Maintain fluid balance throughout body 💦
secondary functions of the kidney
Red Blood Cell Production
Secrete erythropoietin hormone
Help make new blood cells 🩸
Blood Pressure Control
Produce renin hormone
Help regulate cardiovascular system 💓
Vitamin D Activation
Create calcitriol hormone
Help calcium absorption 🦴
Waste Removal! 🗑️
Waste Removal in kidneys
Filter out toxins like urea, creatinine, ammonia
Basically your body’s natural cleaning system!
The two parts that make up a renal corpuscle are the
the glomerulus and glomerular (Bowman’s) capsule
The functional units of the kidney are called:
The functional units of the kidney are called the nephrons,
numbering about a million in each kidney
A nephron consists of two parts:
a renal corpuscle where blood
plasma is filtered and a renal tubule into which the filtered fluid
passes. The renal corpuscle is made up of a ball of capillaries.
the three main sections of the renal tubule
the three main sections of the renal tubule are the proximal
convoluted tubule, the nephron loop (Loop of Henle), and distal
convoluted tubule. Each nephron also has its own blood supply.
collecting duct
Final pathway for urine formation
Receives fluid from multiple nephrons
Key Functions of the collecting duct
Urine Concentration
Removes extra water 💧
Helps control body’s hydration
Hormone Interaction
Responds to Antidiuretic Hormone (ADH)
Adjusts water reabsorption 🔬
Location of the collecting duct
Connects nephron to renal pelvis
Passes through renal medulla 🏞️
Blood Supply of a Nephron
The glomerulus receives blood from a fairly large
afferent arteriole and passes it to a smaller efferent
arteriole.
- The efferent arteriole gives rise to the peritubular
capillary system, which surrounds the renal tubule
macula densa.
Special group of epithelial cells
Located in the distal convoluted tubule 🧬
location and key function of macula densa.
Location:
- Right next to blood vessels
-Sits where afferent and efferent arterioles meet 🩸
Key Function:
- Sodium sensor for the kidney 🧂
- Monitors sodium chloride concentration in tubular fluid
Juxtaglomerular Apparatus (JGA)
Special communication system in the kidney
Tiny but mighty regulatory mechanism 🌟
Primary Function:
-Control renin secretion
-Regulate blood pressure 🩸
Components of Juxtaglomerular Apparatus (JGA)
Macula Densa Cells:
Sodium concentration sensors 🧂
Located in distal convoluted tubule
Juxtaglomerular Cells:
Smooth muscle cells
Found on afferent arteriole 💪
How JGA Works:
When sodium levels drop, macula densa signals JG cells
JG cells release renin hormone
Triggers series of reactions to:
Increase blood volume
Raise blood pressure 📈
Renal Corpuscle (filtration site)
It’s made up of two main parts:
Glomerulus: A tiny ball of capillaries 🔬
Glomerular (Bowman’s) Capsule: The expanded end of the renal tubule that surrounds the glomerulus 🏀
How Does Renal Corpuscle (filtration site) Work?
Imagine it like a super-selective strainer:
Blood enters through an afferent arteriole
Pressure forces water and small solutes through the capillary walls
Large things like blood cells and proteins stay behind 🛡️
The filtered fluid enters the Bowman’s capsule
Renal Tubule (fluid transport)
It’s like a magical transport tube where fluid gets sorted, cleaned, and processed after initial filtration. Think of it as a super-smart conveyor belt for your body’s fluids! 🔬
Key Sections (in order of fluid flow) of Renal Tubule:
Proximal Convoluted Tubule:
-First stop after filtration
-Uses carrier proteins to reabsorb important stuff
-Recovers water, glucose, amino acids 🧪
Loop of Henle:
- Helps concentrate urine
- Manages water and salt balance 💧
Distal Convoluted Tubule:
-Fine-tunes mineral and ion balance
-Adjusts what stays or goes 🔍
Proximal Convoluted Tubule:
-First stop after filtration
-Uses carrier proteins to reabsorb important stuff
-Recovers water, glucose, amino acids 🧪
Loop of Henle:
Loop of Henle:
- Helps concentrate urine
- Manages water and salt balance 💧
Distal Convoluted Tubule:
-Fine-tunes mineral and ion balance
-Adjusts what stays or goes 🔍
Functions of Renal Tubule:
Reabsorption: Keeps what your body needs 🏆
Secretion: Kicks out waste and extra stuff 🚮
Transport: Moves fluid through the kidney 🚂
Glomerular Filtration
It’s the FIRST STEP of urine production - like a microscopic blood cleaning party! 🎉
how does Glomerular Filtration work?
Blood Enters the Glomerulus:
Comes through the afferent arteriole
Packed with water, solutes, and nutrients 💉
Filtration Pressure Magic:
Blood pressure pushes fluid through capillary walls
Only SMALL things can pass through 🛡️
Big stuff like blood cells and proteins STAY BEHIND
pressures involved in Glomerular Filtration
Hydrostatic Pressure: Pushes fluid out
Osmotic Pressure: Tries to keep fluid in
Capsule Pressure: Resists filtration
What Passes Through Glomerular Filtration:
Water
Ions
Glucose
Small waste molecules
Tubular Processes
The tubular processes are all about keeping your body’s internal environment perfectly balanced.
Keeps what the body needs ✅
Removes what the body doesn’t need ❌
key purposes of Tubular Processes
-Selective Recovery 🧲
-Waste Removal 🚮
-Blood Composition Control 🩸
Selective Recovery 🧲 (Tubular Processes)
Reabsorption saves ESSENTIAL substances
Prevents losing valuable:
Water 💧
Glucose 🍬
Amino acids 🥚
Minerals and ions 🔋
Waste Removal 🚮 (Tubular Processes)
Secretion kicks out:
Toxic substances
Excess drugs
Extra ions
Metabolic waste products
Blood Composition Control 🩸 (Tubular Processes)
Maintains perfect blood chemistry
Regulates:
pH levels
Electrolyte balance
Blood volume
Reabsorption
Location: Primarily in Proximal Convoluted Tubule
Goal: Save valuable substances before they’re lost in urine 🚰
What Gets Reabsorbed? 🧲
Water 💧
Glucose 🍬
Amino Acids 🥚
Ions ⚡
Sodium
Chloride
potassium
Reabsorption Mechanisms:
Active Transport:
Uses energy
Moves substances against concentration gradient
Carrier proteins work hard! 🚚
Passive Transport:
Follows concentration gradients
No energy required
Substances flow naturally 🌊
Secretion:
Key Purpose:
Transport substances FROM blood INTO renal tubule
Final chance to remove waste before urine formation 🛡️
What Gets Secreted? 🗑️
Waste Products
Urea
Creatinine
Ammonia
Excess Substances
Drugs
Excess ions
Hydrogen ions
Secretion Mechanisms:
Active Transport:
Uses energy
Moves substances against concentration gradient
Carrier proteins do the heavy lifting! 💪
Specific Targets:
Hydrogen ions (H⁺)
Potassium ions (K⁺)
Organic compounds
Transport Details
Occurs in peritubular capillaries
Last chance to remove unwanted substances
Helps maintain blood chemistry balance 🩸
Urine Formation Stages
Glomerular Filtration 🚰
Tubular Reabsorption 🧲
Tubular Secretion 🚮
Glomerular Filtration
First stage of urine production
Blood plasma filtered through glomerular capillaries
Controlled by hydrostatic and osmotic pressures
About 180 liters filtered DAILY! 🤯
Tubular Reabsorption
Selective substance recovery
Uses carrier proteins
Saves essential substances:
Water 💧
Glucose 🍬
Amino acids 🥚
Minerals 🔋
Active and passive transport mechanisms
Recovers 99% of filtered fluid! 💖
Tubular Secretion
Final waste removal stage
Transports excess substances into renal tubule
Removes:
Waste products
Excess drugs
Extra ions
Last chance to clean the blood! 🧼
Two Capillary Exchange Sites 🔄
Glomerular capillaries
Peritubular capillaries
Key Hormones
Antidiuretic Hormone (ADH) 💧
Aldosterone 🧂
Angiotensin II 🌪️
Antidiuretic Hormone (ADH)
Purpose: Regulates water reabsorption
Superpower: Controls how much water your body keeps
Mechanism: Negative feedback system
Action: Makes kidney tubules more permeable to water 🚰
Aldosterone
Purpose: Sodium and chloride management
Superpower: Stimulates reabsorption of sodium and chloride
Action: Helps control blood pressure and fluid balance 📊
Angiotensin II
Purpose: Blood pressure regulation
Superpower:
-Enhances sodium and chloride reabsorption
-Causes blood vessel constriction
Action: Helps maintain blood pressure 💓
Hormone Harmony 🤝
These hormones work together to:
Maintain fluid balance
Regulate blood pressure
Control ion concentrations
Keep your body’s internal environment stable! 🏆
urine composition
95% water
Contains urea, uric acid, trace amino acids
Urine Characteristics:
Volume: 1-2 liters per 24 hours
Color: Yellow to amber
pH: 4.6-8.0
Specific gravity: 1.001-1.035
Age related Kidney Modifications
Size reduction
Decreased blood flow
Reduced filtration capacity
Common Age-Related Issues in the urinary system:
Urinary tract infections
Increased urination frequency
Urinary retention
Kidney inflammation
Kidney stones
Abnormal Urine Indicators
Glucose presence (diabetes)
Blood cells
Protein
Ketone bodies
Bacterial presence
Daily Filtration:
About 180 LITERS of fluid
electrolyte
Inorganic substance that dissociates in water into charged particles (ions)
Cations:
Positively charged ions (e.g., Na⁺, K⁺)
Anions:
Negatively charged ions (e.g., Cl⁻, HCO₃⁻)
relationship between cation and anion
Normally, cation and anion charges are balanced to maintain electrical neutrality
Homeostasis- Fluid Balance
Incoming fluid and electrolytes = Outgoing fluid and electrolytes
Water redistribution
What is Water Redistribution?
-Water moves super fast through something called osmosis
-It’s all about balance 🤹♀️
-When electrolytes (tiny charged particles) change, water changes too!
Key Principles:
-Water goes where the electrolytes go 💧
-Your body wants to keep everything just right
-If something changes in one place, water will move to balance it out
Total Body Fluid Percentage:
Lean adults: 55-60% of body mass
Newborns: 75%+ water
Intracellular Fluid (ICF)
(2/3 of body fluid)
Located inside cells
High concentrations of:
-Potassium
-Phosphate
-Magnesium
Lower concentrations of:
-Sodium
-Chloride
-Bicarbonate
Extracellular Fluid (ECF)
(1/3 of body fluid)
Located outside cells
Composition:
-80% Interstitial fluid (between tissue cells)
-20% Blood plasma
High concentrations of:
-Sodium
-Chloride
-Bicarbonate
Lower concentrations of:
-Potassium
-Calcium
-Magnesium
-Phosphate
-Sulfate
Water Intake Sources
60% from drinking
30% from moist foods
10% from metabolic water production
Transcellular Fluid:
It’s a special, tiny part of your body’s fluid system that lives in unique spaces! Think of it like secret water hideouts in your body. 🕵️♀️
