Digestive System Overview

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Questions and Answers

What is the primary function of the epiglottis during swallowing?

  • To produce saliva
  • To transport food to the stomach
  • To break down food into smaller particles
  • To prevent food and liquid from entering the airway (correct)

The digestive system breaks down food using a series of chemical and mechanical processes.

True (A)

Describe the role of the liver in the digestive process.

The liver produces bile, which helps to digest fats. It also detoxifies harmful substances and processes nutrients absorbed from the small intestine.

The process of breaking down food into smaller molecules is called ______.

<p>digestion</p> Signup and view all the answers

Match the following structures with their functions in the digestive system:

<p>Stomach = Produces bile for fat digestion Small intestine = Absorption of nutrients into the bloodstream Large intestine = Elimination of waste Esophagus = Transports food from the mouth to the stomach</p> Signup and view all the answers

Which of these is NOT a type of tooth in the human mouth?

<p>Canines (C)</p> Signup and view all the answers

The small intestine is the site where most nutrient absorption occurs.

<p>True (A)</p> Signup and view all the answers

What is the function of the cardiac sphincter and where is it located?

<p>The cardiac sphincter prevents the backflow of stomach contents into the esophagus. It is located at the junction of the esophagus and the stomach.</p> Signup and view all the answers

Which of the following chambers of the heart receives deoxygenated blood from the body?

<p>Right atrium (B)</p> Signup and view all the answers

The aorta is the only artery in the body that carries deoxygenated blood.

<p>False (B)</p> Signup and view all the answers

What is the function of the septum wall in the heart?

<p>The septum wall prevents the mixing of oxygenated and deoxygenated blood between the left and right sides of the heart.</p> Signup and view all the answers

The ______ valve is located between the right ventricle and the pulmonary artery.

<p>pulmonary semilunar</p> Signup and view all the answers

Match the following structures with their corresponding functions in the circulatory system:

<p>Superior vena cava = Carries deoxygenated blood from the upper body to the right atrium Pulmonary artery = Carries deoxygenated blood from the heart to the lungs Left ventricle = Pumps oxygenated blood to the entire body through the aorta Aortic semilunar valve = Prevents backflow of blood into the left ventricle after it is pumped into the aorta</p> Signup and view all the answers

Which of these is NOT a layer of an artery wall?

<p>Capillary sphincters (A)</p> Signup and view all the answers

Veins are designed to carry blood under higher pressure than arteries.

<p>False (B)</p> Signup and view all the answers

What role do valves play in veins?

<p>Valves prevent backflow of blood in veins, especially in the limbs.</p> Signup and view all the answers

The ______ are the smallest blood vessels and are the primary site for exchange of gases, nutrients, and waste products between blood and tissues.

<p>capillaries</p> Signup and view all the answers

Which of the following is a characteristic of capillaries that facilitates efficient diffusion?

<p>Single layer of endothelial cells (C)</p> Signup and view all the answers

The color of blood is determined by the presence or absence of oxygen bound to hemoglobin.

<p>True (A)</p> Signup and view all the answers

What is the function of the smooth muscle layer in arteries?

<p>The smooth muscle layer in arteries allows for vasoconstriction (narrowing) and vasodilation (widening), helping regulate blood pressure and flow.</p> Signup and view all the answers

The ______ is the largest artery in the body, originating from the left ventricle.

<p>aorta</p> Signup and view all the answers

Match the following blood vessel types with their primary functions:

<p>Arteries = Carry blood away from the heart Veins = Carry blood back to the heart Capillaries = Site of exchange between blood and tissues</p> Signup and view all the answers

Which of these is NOT a function of the smooth muscle layer in arteries?

<p>Production of blood cells (D)</p> Signup and view all the answers

The right pulmonary vein carries deoxygenated blood from the right lung to the left atrium.

<p>False (B)</p> Signup and view all the answers

Which of the following organs is responsible for producing insulin and glucagon?

<p>Pancreas (B)</p> Signup and view all the answers

The ______ is the first part of the small intestine where most chemical digestion occurs.

<p>duodenum</p> Signup and view all the answers

The pyloric sphincter controls the release of feces from the rectum.

<p>False (B)</p> Signup and view all the answers

What are villi and what is their role in the small intestine?

<p>Villi are tiny finger-like projections that line the small intestine. They increase the surface area for absorption of nutrients from digested food.</p> Signup and view all the answers

Match the following enzymes with their corresponding substrates:

<p>Amylase = Carbohydrates Pepsin = Proteins Trypsin = Proteins Lactase = Simple carbs Lipase = Fats/lipids</p> Signup and view all the answers

Which of the following is NOT a function of the nasal cavity?

<p>Producing saliva (D)</p> Signup and view all the answers

The ______ is a flap of cartilage that prevents food from entering the trachea during swallowing.

<p>epiglottis</p> Signup and view all the answers

Gas exchange only occurs in the lungs.

<p>False (B)</p> Signup and view all the answers

Explain the role of the diaphragm in breathing.

<p>The diaphragm is a muscle that contracts and relaxes to create pressure changes in the chest cavity, causing air to be drawn into and out of the lungs.</p> Signup and view all the answers

Which of the following structures is responsible for transporting oxygen-rich blood from the lungs to the heart?

<p>Pulmonary vein (A)</p> Signup and view all the answers

The ______ is the primary muscle responsible for breathing.

<p>diaphragm</p> Signup and view all the answers

The trachea is lined with cilia that move mucus and trapped particles towards the lungs.

<p>False (B)</p> Signup and view all the answers

What is the main function of the alveoli?

<p>Alveoli are tiny air sacs in the lungs where gas exchange occurs. They are responsible for taking in oxygen from the air and releasing carbon dioxide from the blood.</p> Signup and view all the answers

Which of these structures is NOT involved in the process of cleansing the air we breathe?

<p>Diaphragm (A)</p> Signup and view all the answers

The ______ is the tube that connects the mouth to the stomach.

<p>esophagus</p> Signup and view all the answers

The small intestine is longer than the large intestine.

<p>True (A)</p> Signup and view all the answers

What is the function of bile and where is it produced?

<p>Bile is a fluid produced by the liver that aids in the digestion of fats. It emulsifies fats, breaking them down into smaller droplets for better digestion.</p> Signup and view all the answers

Which of these enzymes is responsible for breaking down carbohydrates into simple sugars?

<p>Amylase (C)</p> Signup and view all the answers

Flashcards

Digestion

The process of breaking down food into smaller molecules that the body can absorb.

Absorption

The process by which nutrients from digested food are absorbed into the bloodstream.

Egestion

The passage of undigested food from body.

Peristalsis

Muscular contractions that move food through the digestive tract.

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Epiglottis

A flap of tissue that covers the trachea during swallowing, preventing food from entering the airway.

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Cardiac Sphincter

A muscular ring that controls the flow of food from the esophagus to the stomach.

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Bile

A substance produced by the liver that helps break down fats.

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Incisors

A type of tooth used for cutting food.

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Superior Vena Cava

Carries deoxygenated blood from the head, arms, and upper chest to the right atrium.

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Inferior Vena Cava

Carries deoxygenated blood from the lower body (abdomen, legs, pelvis) to the right atrium.

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Right Atrium

Receives deoxygenated blood from the body via the superior and inferior vena cava.

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Right Ventricle

Pumps deoxygenated blood to the lungs through the pulmonary artery.

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Right Pulmonary Vein

Carries oxygenated blood from the right lung to the left atrium.

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Pulmonary Artery

Carries deoxygenated blood from the heart to the lungs for oxygenation.

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Left Atrium

Receives oxygenated blood from the lungs through the pulmonary veins.

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Left Ventricle

Pumps oxygenated blood to the entire body through the aorta.

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Aorta

Largest artery in the body, distributing oxygenated blood to the entire body except the lungs.

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Septum Wall

The wall separating the right and left sides of the heart, preventing mixing of oxygenated and deoxygenated blood.

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Right Atrioventricular Valve (Tricuspid Valve)

Prevents backflow of blood from the right ventricle to the right atrium.

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Left Atrioventricular Valve (Bicuspid/Mitral Valve)

Prevents backflow of blood from the left ventricle to the left atrium.

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Pulmonary Semilunar Valve

Prevents backflow of blood into the right ventricle after it is pumped to the lungs.

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Aortic Semilunar Valve

Prevents backflow of blood into the left ventricle after it is pumped into the aorta.

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Arteries

Blood vessels that carry blood away from the heart.

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Duodenum

The first part of the small intestine where most chemical digestion occurs. It receives bile and pancreatic enzymes.

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Pyloric Sphincter

A ring of muscle that controls the flow of partially digested food (chyme) from the stomach into the duodenum.

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Villi

Tiny finger-like projections that line the small intestine, increasing surface area for absorption of nutrients.

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Microvilli

Even smaller projections on top of the villi, further increasing surface area for nutrient absorption.

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Ventilation

The process of moving air in and out of the lungs (breathing).

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Gas Exchange

The exchange of gases (oxygen and carbon dioxide) between the blood and the environment (lungs or tissues).

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Alveoli

Tiny air sacs in the lungs where gas exchange occurs.

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Cellular Respiration

The process by which glucose in food is converted into ATP (energy) using oxygen.

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Cilia

Hair-like structures in the nasal cavity that trap dust, dirt, and microorganisms from the air.

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Mucus

A sticky substance produced by the nasal lining that helps trap dust, dirt, and microorganisms.

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Diaphragm

The large muscle located below the lungs that helps with breathing.

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Macrophages

White blood cells that engulf and destroy foreign particles and pathogens.

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Surfactant

A fluid secreted in the alveoli that helps keep them moist and prevents them from collapsing.

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Study Notes

Digestive System

  • Ingestion: Taking food into the body. Food enters the digestive system to begin the process.
  • Digestion: Breaking down food into absorbable molecules. Food needs to be broken down to a molecular level to be absorbed into the bloodstream.
  • Absorption: Nutrients are absorbed into the bloodstream. This is crucial for delivering needed nutrients to the body's cells.
  • Egestion: Removal of undigested materials from the body. This involves releasing unused materials as feces.

Food Processing Stages

  • Food: The ingested substance.
  • Bolus: Chewed food, forming a ball that's swallowed.
  • Chyme: Partially digested food in the stomach, forming a paste-like substance. The increased surface area allows more enzyme contact.
  • Fecal matter: Undigested food and waste in its final form before elimination.

Tongue Function

  • Tongues assist in chewing by moving food around.
  • Evolutionary adaptations favor taste preferences for energy-rich foods and discourage tasting or ingesting harmful substances.

Teeth Types

  • Incisors: Front teeth, for cutting.
  • Bicuspids: Between incisors and molars, used for piercing.
  • Molars: Grind food into smaller pieces.

Salivary Glands

  • Produce saliva, containing enzymes for digestion and mucus for lubrication. Saliva helps with swallowing and initial breaking down of food.

Epiglottis

  • Covers the trachea during swallowing, preventing food/liquid entry into the airways.

Esophagus

  • Transports food and liquids from mouth to stomach via peristalsis (muscle contractions).

Liver

  • Produces bile for fat digestion, detoxifies harmful substances, and processes absorbed nutrients. It assists in the processing and delivery of essential nutrients and detoxification of harmful materials.

Cardiac Sphincter

  • Prevents stomach contents from refluxing into the esophagus.

Stomach

  • Breaks down food mechanically (churning) and chemically (gastric juices/enzymes).

Pancreas

  • Produces digestive enzymes (amylase, lipase, etc.) and hormones (insulin, glucagon).

Pancreatic Duct

  • Carries pancreatic enzymes to the small intestine.

Anal Sphincter

  • Controls the release of feces.

Duodenum

  • First part of the small intestine, site of major chemical digestion. Receives digestive enzymes and bile.

Gallbladder

  • Stores and concentrates bile from the liver, releasing it into the small intestine for fat digestion. This release of bile is important for fat processing and digestion.

Pyloric Sphincter

  • Regulates the flow of chyme from the stomach to the small intestine.

Small Intestine

  • 7 meters long.
  • Villi and microvilli increase surface area for absorption.
  • Involved in absorbing nutrients from digested food into the blood.
  • Villi and microvilli are essential for increasing the surface area available for absorption, maximizing the amount of nutrients absorbed.

Diarrhea

  • Can lead to dehydration.

Enzymes (Digestive)

Enzyme Substrate Product Location of Production Location of Action
Amylase Carbohydrates Simple sugars (e.g., glucose) Salivary glands & Pancreas Mouth & small intestine
Pepsin Proteins Peptides Stomach wall Stomach
Trypsin Proteins Peptides Pancreas Small intestine (duodenum)
Lactase Lactose Glucose & Galactose Pancreas Small intestine
Maltase Maltose Glucose Pancreas Small intestine
Lipase Fats/lipids Glycerol & fatty acids Pancreas Small intestine
Erepsin Peptides Amino acids Small intestine wall Small intestine
Sucrase Sucrose Glucose and fructose Small intestine wall Small intestine

Respiratory System

  • Purpose: Take in oxygen, remove carbon dioxide to produce energy via cellular respiration.
  • Ventilation: Movement of air into/out of lungs.
  • Gas exchange: Oxygen and carbon dioxide diffusing across membranes in lungs and body tissues.

Air Conditioning in the Respiratory System

  • Cleaning: Filtering out particles to prevent lung damage.
  • Warming: Bringing air to body temperature for optimal gas exchange.
  • Moistening: Adding moisture to keep the respiratory surfaces moist for proper gas exchange. Air must be in a moist, liquid state for gas exchange to occur.

Respiratory Structures (Function and Role)

  • Nasal cavity: Warms, moistens and cleanses air.
  • Mouth cavity: Secondary air pathway.
  • Larynx: Protects airways.
  • Lungs: Primary site of gas exchange.
  • Bronchi: Branching pathways to lungs.
  • Bronchioles: Fine airways leading to alveoli.
  • Alveoli: Tiny air sacs for gas exchange.
  • Diaphragm: Muscle for breathing.
  • Pharynx: Shared pathway for air and food.
  • Trachea: Windpipe carrying air.

Circulatory System

  • Superior Vena Cava: Returns deoxygenated blood from upper body.
  • Inferior Vena Cava: Returns deoxygenated blood from lower body.
  • Right Pulmonary Vein: Carries oxygenated blood to heart from right lung.
  • Left Pulmonary Vein: Carries oxygenated blood to heart from left lung.
  • Right & Left Atrium: Collect blood.
  • Right & Left Ventricle: Pump blood through circulatory system.
  • Aorta: Carries oxygenated blood away from the heart.
  • Pulmonary Artery: Carries deoxygenated blood to lungs.
  • Septum: Divides the heart into left & right halves, preventing mixing of blood types
  • Heart Valves: Ensure unidirectional blood flow.

Blood Characteristics

  • Hemoglobin: Protein that carries oxygen, determining blood color. Oxygenated blood is red, deoxygenated blood appears darker. Iron in the hemoglobin is responsible for the red color change.

Blood Vessels

  • Arteries: Carry blood away from the heart, have thick walls.
  • Capillaries: Exchange nutrients and gases, have extremely thin walls.
  • Veins: Carry blood back to the heart, have thin walls & valves.

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