Glomerular Filtration Rate (GFR) Regulation Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the normal Glomerular Filtration Rate (GFR) range?

120-125 ml/min (correct)

60-80 ml/min

180-200 ml/min

40-50 ml/min

What is the main mechanism to increase blood pressure in the kidneys?

Tubuloglomerular feedback mechanism

Renin-Angiotensin-Aldosterone mechanism (correct)

Sympathetic nervous system

Myogenic mechanism

What determines who gets filtered and who doesn’t in the kidneys?

Total plasma volume filtered every 40 min

Total plasma volume filtered every 30 min

Total plasma volume filtered every 22 min (correct)

Total plasma volume filtered every 10 min

What is the function of macula densa cells in the kidneys?

Respond to filtrate NaCl concentration Signup and view all the answers

What is the net filtration pressure (NFP) equation in the kidneys?

NFP = Outward pressures – Inward Pressures Signup and view all the answers

What is the normal daily volume of fluid filtered through the glomerulus?

About 180 L/day Signup and view all the answers

What is the response of the sympathetic nervous system when extracellular fluid (ECF) is low?

It constricts smooth muscles and afferent arterioles Signup and view all the answers

What is the main determinant of who gets filtered and who doesn’t in the kidneys?

Total plasma volume filtered every 22 min Signup and view all the answers

What is a chemical buffer?

A system of one or more compounds that resist changes in pH when a strong acid or base is added Signup and view all the answers

Which is the only important extracellular fluid (ECF) buffer?

Bicarbonate – mixture of carbonic acid and sodium bicarbonate Signup and view all the answers

How do the lungs respond to increased H+ levels?

Increase respiration rate to remove more CO2 from the blood Signup and view all the answers

How do the kidneys regulate acid-base balance?

By adjusting the amount of bicarbonate in the blood Signup and view all the answers

What is the role of phosphate as a buffer?

It is nearly identical to the bicarbonate buffering system Signup and view all the answers

How do the kidneys prevent acidosis?

By secreting H+ ions to prevent acidosis Signup and view all the answers

What happens when the body is in alkalosis?

Intercalated type B cells in the collecting duct exhibit net HCO3- secretion while reclaiming H+ to acidify the blood Signup and view all the answers

What is the role of protein as a buffer?

It acts as a buffer in the intracellular fluid (ICF) Signup and view all the answers

What is the main mechanism for increasing blood pressure in hormonal regulation of GFR?

Release of renin by granular cells and activation of the sympathetic nervous system Signup and view all the answers

What is the primary method of sodium reabsorption in the kidneys?

Transcellular and active transport Signup and view all the answers

What is the function of aldosterone in the kidneys?

Regulates sodium reabsorption and potassium secretion Signup and view all the answers

What is the role of aquaporins in the kidneys?

Facilitate facultative water reabsorption Signup and view all the answers

How is glucose reabsorbed in the kidneys?

By secondary active transport Signup and view all the answers

What is the function of the myogenic regulation of GFR?

Preventing glomerular blood pressure from reaching damaging levels Signup and view all the answers

What is the effect of norepinephrine released by sympathetic nerve fibers on GFR?

Causes vasoconstriction, leading to decreased GFR Signup and view all the answers

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

Regulation of water reabsorption through aquaporins Signup and view all the answers

What is the function of the Na-K ATPase pump in the kidneys?

Active transport of sodium and potassium Signup and view all the answers

How do the kidneys contribute to acid-base balance?

Regulating the excretion of hydrogen ions and reabsorption of bicarbonate ions Signup and view all the answers

What is the consequence of reaching the transport maximum for a substance in the kidneys?

Excess of the substance is excreted in urine Signup and view all the answers

What is the function of the renin-angiotensin-aldosterone mechanism in the kidneys?

Increasing blood pressure Signup and view all the answers

What is the major function of the mucosa layer in the gastrointestinal tract?

Secrete mucus, digestive enzymes and hormones Signup and view all the answers

What is the main function of the submucosa layer in the gastrointestinal tract?

Contain rich supply of blood and lymphatic vessels Signup and view all the answers

What is the primary responsibility of the muscularis externa in the gastrointestinal tract?

Responsible for segmentation and peristalsis Signup and view all the answers

What is the composition of the serosa layer in the gastrointestinal tract?

Areolar connective tissue covered with mesothelium Signup and view all the answers

Which layer of the gastrointestinal wall is responsible for the elasticity to allow the stomach to stretch and return to its normal size temporarily for large meals?

Submucosa layer Signup and view all the answers

What is the primary function of the muscularis mucosae within the gastrointestinal wall?

Alter the shape of the lumen Signup and view all the answers

What is the primary function of the inner circular layer of smooth muscle cells within the muscularis externa?

Segmentation of food Signup and view all the answers

What is the major function of the outer longitudinal layer of smooth muscle cells within the muscularis externa?

Peristalsis of food Signup and view all the answers

What is the main function of pancreatic lipase?

Digesting triglycerides into 2-monoglyceride and two free fatty acids for absorption Signup and view all the answers

What is the role of amylase in pancreatic secretions?

Hydrolysing starch into maltose, maltotriose, and limit dextrins Signup and view all the answers

What is the function of the pancreas and liver in normal fat digestion?

Dependence on secretions from both for normal fat digestion Signup and view all the answers

What is the effect of Orlistat (Xenical) on fat digestion?

Inhibits pancreatic lipase Signup and view all the answers

What do trypsin and chymotrypsin do to proteins?

Digest proteins into peptides Signup and view all the answers

What is the main function of the pancreas in digestion?

Producing digestive enzymes and bicarbonate Signup and view all the answers

What is the primary role of the colon in digestion?

Absorbing water and electrolytes, storing undigested food, and eliminating solid waste Signup and view all the answers

What is the role of peristalsis in the colon?

Encouraging feces movement towards the rectum Signup and view all the answers

What mediates the pattern of smooth muscle contractions in peristalsis?

Enteric nervous system Signup and view all the answers

What is the defecation reflex?

An involuntary response promoting or inhibiting bowel movement Signup and view all the answers

What do trypsin and chymotrypsinogen activate in the small intestine?

Chymotrypsinogen and additional trypsinogen Signup and view all the answers

What is the function of pancreatic duct cells in digestion?

Secrete bicarbonate and water into pancreatic juice to neutralize stomach acid Signup and view all the answers

Which cells in the stomach produce hydrochloric acid (HCl) and intrinsic factor?

Parietal cells Signup and view all the answers

What is the role of intrinsic factor in the small intestine?

Aids in vitamin B12 absorption Signup and view all the answers

Which factors regulate gastric secretion?

Neural and hormonal factors Signup and view all the answers

How many phases of gastric secretion are there?

Three Signup and view all the answers

Which nerve reflexes play a key role in regulating gastric secretion?

Long (vagus nerve-mediated) and short (local enteric) nerve reflexes Signup and view all the answers

What is the primary function of the exocrine glands in the pancreas?

Produce digestive enzymes and bicarbonate Signup and view all the answers

What do pancreatic juices assist in the digestion of?

Fats, carbohydrates, and proteins Signup and view all the answers

Which cells of the pancreas are responsible for producing and transporting enzymes into the duodenum?

Acinar cells Signup and view all the answers

What is the major pancreatic protease activated by enterokinase in the intestinal mucosa?

Trypsinogen Signup and view all the answers

What is the primary role of bile produced by the pancreas?

Aids in digestion Signup and view all the answers

What is the function of pancreatic juice in reducing digestible macromolecules into forms capable of absorption?

Contains digestive enzymes and bicarbonate Signup and view all the answers

What is the primary function of trypsinogen in the intestinal mucosa?

Activated by enterokinase to digest proteins Signup and view all the answers

What triggers the intrinsic myenteric defecation reflex?

Distention of the rectal wall Signup and view all the answers

Which nerve fibers are involved in the parasympathetic defecation reflex?

Parasympathetic nerve fibers Signup and view all the answers

Where is the liver located in the body?

Right hypochondriac and epigastric region Signup and view all the answers

What are the main components of bile?

Bile salts, bile pigments, cholesterol, triglycerides, and phospholipids Signup and view all the answers

What is the primary function of bile salts in digestion?

Aiding in the digestion and absorption of fats Signup and view all the answers

What is bilirubin?

The chief bile pigment and a waste product of heme Signup and view all the answers

What is the main role of hepatocytes in the liver?

Bile secretion, glucose storage, protein synthesis, and detoxification Signup and view all the answers

What is the process of protein absorption essential for?

Body's growth, repair, and maintenance Signup and view all the answers

Where does the process of protein absorption begin?

Stomach Signup and view all the answers

What is the composition of bile?

Alkaline yellow/green fluid Signup and view all the answers

What is the enterohepatic circulation responsible for recycling?

Bile salts Signup and view all the answers

What is the main function of the liver in bile production?

Bile secretion Signup and view all the answers

Which organ primarily aids in the propulsion of food through peristalsis?

Pharynx Signup and view all the answers

What is the primary function of the hepatic portal circulation?

Collects nutrient-rich venous blood from the digestive viscera and delivers it to the liver Signup and view all the answers

Which enzyme is primarily responsible for protein digestion in the stomach?

Pepsin Signup and view all the answers

What is the primary function of the large intestine in the digestive process?

Absorption of water and electrolytes Signup and view all the answers

Where does the process of mechanical breakdown of food primarily occur?

Mouth and stomach Signup and view all the answers

Which blood vessels supply the intestines with blood?

Celiac artery, superior mesenteric arteries, and inferior mesenteric arteries Signup and view all the answers

What is the primary role of the peritoneum, mesentery, and omentum in the abdominal anatomy?

Provide structural support and routes for blood vessels, lymphatics, and nerves Signup and view all the answers

What is the primary function of the alimentary canal and accessory organs in the digestive system?

Breaking down food and converting it to energy Signup and view all the answers

What is the purpose of salivary amylase secretion in the mouth?

Initiation of polysaccharide digestion Signup and view all the answers

Which part of the digestive system is involved in the breakdown, digestion, and absorption of various nutrients including carbs, protein, fat, and nucleic acid?

Small intestines Signup and view all the answers

What is the primary function of the blood supply from the splanchnic circulation to the intestines?

Provide oxygen and nutrients for digestion and absorption Signup and view all the answers

What is the primary purpose of the process of digestion in the alimentary canal?

Breaking down food by mechanical and enzymatic action into substances that can be used by the body Signup and view all the answers

Study Notes

Regulation Mechanisms of Glomerular Filtration Rate (GFR)

Myogenic regulation: Vascular smooth muscle contracts when stretched and relaxes when not stretched, preventing glomerular blood pressure from reaching damaging levels.
Autoregulation: Kidneys adjust their own resistance to maintain a nearly constant GFR despite fluctuations in arterial blood pressure, using myogenic and tubuloglomerular feedback.
Neural regulation: Norepinephrine released by sympathetic nerve fibers causes vasoconstriction, increasing peripheral resistance and blood pressure, leading to decreased GFR.
Hormonal regulation: Renin-Angiotensin-Aldosterone mechanism is the main mechanism for increasing blood pressure, involving the release of renin by granular cells and activation of the sympathetic nervous system.
Tubules I: Water reabsorption in the proximal convoluted tubule (PCT) is obligatory, while in the collecting ducts, aquaporins are inserted based on osmolality levels signaling the release or inhibition of ADH, facilitating facultative water reabsorption.
Tubules II: Sodium is primarily reabsorbed through transcellular and active transport, involving the Na-K ATPase pump and the role of aldosterone in retaining sodium and potassium channels in the collecting ducts and distal convoluted tubule (DCT).
Tubules III: Glucose is reabsorbed by secondary active transport and transport maximum is reached when transport proteins are saturated, leading to the excess excretion in urine.
Endocrine function of the kidneys: Renin is released by the kidneys to raise blood pressure by initiating the renin-angiotensin-aldosterone mechanism, while aldosterone regulates sodium reabsorption and potassium secretion.
Acid-base balance: Our pH is 7 due to the kidneys' role in regulating the acid-base balance through the excretion of hydrogen ions and reabsorption of bicarbonate ions.

Gastrointestinal Physiology and Pancreatic Functions

Parietal cells in the stomach produce hydrochloric acid (HCl) and intrinsic factor, facilitated by microvilli providing surface area for secretion
HCl is crucial for activating pepsin, a protein-digesting enzyme, while intrinsic factor aids in vitamin B12 absorption in the small intestine
Gastric secretion is regulated by both neural (vagus and sympathetic nerves) and hormonal factors (gastrin, ACh, histamine)
Three phases of gastric secretion: cephalic (before food enters stomach), gastric (when food reaches stomach), and intestinal (stimulatory and inhibitory components)
The autonomic nervous system, including long (vagus nerve-mediated) and short (local enteric) nerve reflexes, plays a key role in regulating gastric secretion
The enteric nervous system, an in-house nerve supply of the alimentary canal, has both short and long reflex arcs and communicates widely to regulate digestive system activity
The pancreas contains exocrine glands that produce digestive enzymes (proteases, amylase, lipase) and bicarbonate critical to proper digestion
Pancreatic juices, released into the duodenum, assist in the digestion of fats, carbohydrates, and proteins
The pancreas also produces bile, which is released into the duodenum and aids in digestion
Acinar cells are the exocrine cells of the pancreas responsible for producing and transporting enzymes into the duodenum
Pancreatic juice consists of digestive enzymes (proteases) and bicarbonate, essential for reducing digestible macromolecules into forms capable of absorption
Trypsinogen, a major pancreatic protease, is activated by enterokinase in the intestinal mucosa to digest proteins

Defecation Reflexes and Anatomy of Liver and Bile

Defecation involves two main reflexes: intrinsic myenteric defecation reflex and parasympathetic defecation reflex.
Intrinsic myenteric defecation reflex is triggered by the distention of the rectal wall, leading to increased peristalsis and relaxation of the internal anal sphincter.
Parasympathetic defecation reflex works similarly to the intrinsic reflex, but involves parasympathetic nerve fibers and enhances the process.
Other defecation reflexes include gastrocolic, gastrolienal, enterogastric, and duodenocolic reflexes, each triggered by specific stimuli in the gastrointestinal system.
The liver, the largest gland in the body, has four lobes and is located in the right hypochondriac and epigastric region, mostly within the ribcage.
Liver cells, hepatocytes, form liver lobules and are involved in bile secretion, glucose storage, protein synthesis, and detoxification.
Bile, an alkaline yellow/green fluid, contains bile salts, bile pigments, cholesterol, triglycerides, and phospholipids, with bile salts aiding in the digestive process.
Bile salts, cholesterol derivatives, are essential for the digestion and absorption of fats and are recycled through the enterohepatic circulation.
Bilirubin, the chief bile pigment, is a waste product of heme from broken down erythrocytes and is excreted into bile and metabolized by bacteria in the small intestine.
Protein absorption involves dietary protein and protein from used mucosa, with the process beginning in the stomach and continuing in the small intestine.
The process of protein absorption includes digestion by stomach acid and enzymes, absorption in the small intestine, and transport to the liver via the hepatic portal system.
Protein absorption is essential for the body's growth, repair, and maintenance, and any disruptions in the process can lead to malnutrition and health issues.

Anatomy and Function of the Digestive System

The digestive system consists of the alimentary canal and accessory organs, with the purpose of breaking down food and converting it to energy.
Essential activities of the digestive system include ingestion, propulsion, mechanical breakdown, digestion, absorption, and defecation.
The mouth and accessory organs are involved in ingestion, propulsion, breakdown, and digestion through processes like chewing and salivary amylase secretion.
The pharynx and esophagus mainly aid in propulsion through peristalsis.
The stomach contributes to mechanical breakdown, protein digestion, and minimal absorption, with the production of pepsin and hydrochloric acid.
The small intestines and associated organs facilitate breakdown, digestion, and absorption of various nutrients, including carbs, protein, fat, and nucleic acid.
The large intestine is involved in the digestion of remaining food by enteric bacteria, absorption of water and electrolytes, propulsion of feces, and defecation.
The abdominal anatomy includes the peritoneum, mesentery, and omentum, which provide structural support and routes for blood vessels, lymphatics, and nerves.
The blood supply to the intestines comes from the splanchnic circulation, including the celiac artery, superior mesenteric arteries, and inferior mesenteric arteries.
The hepatic portal circulation collects nutrient-rich venous blood from the digestive viscera and delivers it to the liver.
Digestion is the process of breaking down food by mechanical and enzymatic action in the alimentary canal into substances that can be used by the body.
Digestive steps in the mouth include ingestion, mechanical breakdown through chewing, initiation of propulsion by swallowing, and the start of polysaccharide digestion, while the stomach continues mechanical breakdown and protein digestion, primarily through pepsin and hydrochloric acid.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of the regulation mechanisms of Glomerular Filtration Rate (GFR) with this quiz. Explore topics such as myogenic regulation, autoregulation, neural regulation, hormonal regulation, tubular reabsorption, endocrine function, and acid-base balance in the kidneys.