A&P 2 Exam 6 Simplified Notes PDF

A&P 2 Exam 6 Digestive and Respiratory System Digestive System The Respiratory System - Simplified Main Jobs of the Respiratory System: 1. Bring oxygen into the blood. 2. Remove carbon dioxide from the blood. 3. Keep the body’s acid/base balance stable....

A&P 2 Exam 6 Digestive and Respiratory System Digestive System The Respiratory System - Simplified Main Jobs of the Respiratory System: 1. Bring oxygen into the blood. 2. Remove carbon dioxide from the blood. 3. Keep the body’s acid/base balance stable. The Cardiovascular System (the heart and blood vessels) helps by carrying these gases between the lungs and the rest of the body. Other important functions: 4. Helps with sense of smell. 5. Filters the air we breathe in. 6. Produces sounds (like when we speak). 7. Gets rid of waste gases. Parts of the Respiratory System: 1. Upper Respiratory System: Includes the nose, throat (pharynx), and other related parts. 2. Lower Respiratory System: Includes the voice box (larynx), windpipe (trachea), bronchi, and lungs. Two Ways to Think About the Respiratory System: 1. Conducting Portion: Air travels through the nose, throat, larynx, trachea, and bronchi to get to the lungs. 2. Respiratory Portion: The part where oxygen and carbon dioxide actually exchange in the alveoli (tiny air sacs in the lungs). What’s the DiSerence Between Respiration and Ventilation? Respiration: The exchange of gases (oxygen and carbon dioxide) between the atmosphere, blood, and cells. o External Respiration is gas exchange between the lungs and blood. o Internal Respiration is gas exchange between the blood and the cells. Ventilation (Breathing): The act of moving air in and out of the lungs. o Inspiration (Inhalation): Breathing in, where the chest expands and air enters the lungs. o Expiration (Exhalation): Breathing out, where the chest shrinks and air leaves the lungs. Air Volumes: 1. Total Lung Capacity: All the air in your lungs (including air you can't fully exhale). 2. Tidal Volume: The normal amount of air you breathe in and out with each breath. 3. Inspiratory Reserve: Extra air you can inhale after a normal breath. 4. Expiratory Reserve: Extra air you can exhale after a normal breath. 5. Residual Volume: Air that stays in your lungs even after you breathe out as much as you can. 6. Minute Respiratory Volume: The total air you breathe in and out in one minute. The Nose and Pharynx - Simplified Functions of the Nose:  1. Warm the air you breathe using blood vessels. 2. Moisten the air with mucus. 3. Filter the air by trapping dust with mucus and moving particles with tiny hairs (cilia) to the throat. 4. Helps with vocal sounds by providing resonance (echo). External Nose: Made of bone and cartilage, covered with skin and lined with mucus. o External Nares: Your nostrils. o Vestibule: Area just inside the nostrils with coarse hairs. Tip of the nose is flexible cartilage; Bridge is made of bone. The nose is divided into right and left sides by the nasal septum (like a wall inside the heart). Internal Nose: Connects to the pharynx (throat) through two openings called internal nares (choanae). Pharynx (Throat) - Simplified Functions of the Pharynx: 1. Passageway for air and food. 2. Helps with speech by providing a space for sound to travel. 3 Parts of the Pharynx: 1. Nasopharynx (top part): o Starts at the internal nares (where air enters from the nose) and goes down to the soft palate. o Eustachian Tubes: Help balance air pressure between the middle ear and the outside environment. 2. Oropharynx (middle part): o Goes from the soft palate to the level of the hyoid bone (in the throat). o It’s shared for both breathing (air) and eating (food, drink). o Has two pairs of tonsils: palatine and lingual tonsils. 3. Laryngopharynx (bottom part): o Extends from the hyoid bone to the larynx (voice box). o It leads to both the esophagus (food tube) and the larynx (voice box), serving both air and food. Larynx (Voice Box) - Simplified The larynx connects the throat (pharynx) to the windpipe (trachea). It has vocal folds (also called vocal cords) that make sound when air passes through them. o Tight folds make high-pitched sounds. o Looser folds make low-pitched sounds. 3 Types of Cartilage in the Larynx: 1. Epiglottis: o A flap that covers the airway (glottis) when swallowing, preventing food from going into the windpipe.  o It moves up when you swallow, closing oZ the airway like a lid. 2. Thyroid Cartilage (Adam's Apple): o The big piece of cartilage in front of the larynx, which gives it a triangular shape. o It’s larger in men than women. 3. Cricoid Cartilage: o The base of the larynx, found below the thyroid cartilage. o It’s important for emergency procedures to open the airway. Trachea (Windpipe) - Simplified The trachea is made up of C-shaped cartilage rings stacked on top of each other. Structure of the Trachea: 1. Open part of the C's: Allows the esophagus to expand slightly when swallowing food. 2. Solid part of the C's: Keeps the trachea open so air can pass through easily without the walls collapsing. 3. The rings are held together by smooth muscle and the trachea is lined with tiny hairs (cilia) that help move mucus and particles up and out. The trachea starts at the larynx and goes down into the chest, where it splits into the right and left bronchi. Carina - Simplified The carina is the ridge where the trachea splits into the right and left bronchi. It’s very sensitive and triggers the cough reflex when something irritates it. If the carina is widened or distorted, it could be a sign of serious problems, like cancer aZecting nearby lymph nodes. Bronchi Division and Lungs - Simplified Bronchial Tree: 1. Trachea (Windpipe) divides into: o Primary Bronchi (one for each lung). § Right lung: 3 lobes. § Left lung: 2 lobes. 2. The Primary Bronchi split into Secondary Bronchi (one for each lobe). 3. Secondary Bronchi split into Tertiary Bronchi. 4. Tertiary Bronchi split into smaller tubes called Bronchioles. 5. Bronchioles divide further into Terminal Bronchioles. 6. Terminal Bronchioles lead to Respiratory Bronchioles. 7. Respiratory Bronchioles lead to Alveolar Ducts. 8. Alveoli: Tiny air sacs where gas exchange (oxygen and carbon dioxide) happens. Lungs - Simplified The lungs are covered by two layers of membrane: 1. Parietal Pleura: Outer layer that surrounds and protects the lungs.  2. Visceral Pleura: Inner layer that covers the lungs. o Between these layers is a small space called the pleural cavity filled with pleural fluid, which reduces friction when breathing. Left Lung has 2 lobes. Right Lung has 3 lobes. Respiratory Muscles - Simplified 1. Diaphragm: Main muscle for breathing in. It’s controlled by the phrenic nerve and helps expand the chest. 2. External Intercostals: Help raise the ribs to inhale. Controlled by the intercostal nerve. 3. Internal Intercostals: Help lower the ribs to exhale. Also controlled by the intercostal nerve. Respiratory Problems - Simplified 1. Bronchial Asthma: Airway spasms make it hard to breathe, causing wheezing and diZiculty exhaling. It’s often triggered by allergies. 2. Bronchitis: Inflammation of the bronchi (airways) that leads to coughing up thick mucus. Smoking is a common cause. 3. Emphysema: The walls of the alveoli break down, causing the lungs to stay inflated. This makes breathing harder, especially exhaling. It’s caused by long-term irritation, like smoking. 4. Chronic Obstructive Pulmonary Disease (COPD): A group of diseases (including asthma, bronchitis, and emphysema) that block airflow and make it hard to breathe. 5. Pneumonia: Infection in the lungs that causes the alveoli to fill with fluid, reducing air space and making it hard to breathe. 6. Tuberculosis (TB): A bacterial infection that destroys lung tissue and replaces it with scar tissue, which makes it harder to breathe. 7. Coryza (Common Cold): A viral infection causing a stuZy nose and coughing. It usually doesn’t have a fever, and antibiotics don’t help. 8. Influenza (Flu): A viral infection causing fever, chills, and muscle aches, along with cold-like symptoms. 9. Pulmonary Embolism: A blood clot blocks blood flow in the lungs, which can be life-threatening. 10. Pulmonary Edema: Fluid builds up in the lungs, often due to heart failure, making it diZicult to breathe. Key Medical Terms Related to the Respiratory System - Simplified Apnea: Not breathing. Asphyxia: Lack of oxygen, often because of low air oxygen levels. Aspiration: Breathing in something like food, water, or a foreign object into the lungs. Diphtheria: A serious bacterial infection that makes the airway membranes thick and leathery, which can block air and cause suZocation.  Diaphoresis: Excessive sweating. Dyspnea: DiZicult or painful breathing. Hypoxia: Not enough oxygen getting to the body's cells. Ortopnea: DiZiculty breathing when lying down. Pallor: Paleness of the skin. Tachypnea: Fast breathing. Respiratory Acidosis: When the blood becomes too acidic because the body can't get rid of enough carbon dioxide, often due to lung disease or not breathing enough. Respiratory Alkalosis: When the blood becomes too basic because the body gets rid of too much carbon dioxide, often due to fast breathing or certain drugs. Epistaxis: Nosebleed. Pleurisy: Inflammation of the pleura (the lining around the lungs), causing pain when breathing.  Digestive System Digestive System - Simplified The digestive system has two main parts: 1. GI Tract: The path that food travels through. o Buccal Cavity (Mouth) → Pharynx → Esophagus → Stomach → Small Intestine → Large Intestine 2. Accessory Organs: Help in digestion but are not part of the path food takes. o Liver, Gallbladder, and Pancreas Contents of the Mouth (Buccal Cavity): 1. Lips: The outer part of the mouth, soft and not very thick. 2. Teeth and Gums: Teeth help grind food, and gums hold the teeth in place. 3. Tongue: Helps mix and move food around in the mouth. 4. Salivary Glands: Produce saliva, which helps in digestion. 5. Uvula: A small piece of tissue hanging at the back of the mouth that helps with swallowing. 6. Palates: o Hard Palate: The bony part of the roof of your mouth. o Soft Palate: The soft, fleshy part at the back of the mouth. 7. Cheeks: The sides of the mouth, lined with soft tissue. Processes in the Mouth: Mastication (Chewing): The process of breaking food into smaller pieces using your teeth and mixing it with saliva. This forms a soft mass called a bolus, which is easy to swallow. Deglutition (Swallowing): The action of moving food from the mouth to the stomach with the help of saliva and mucus. Digestion: Starts in the mouth with the help of enzymes (like amylase) and mucus. Pharynx (Throat): The pharynx is a muscular tube lined with mucus. It doesn’t digest food but helps move it from the mouth to the esophagus. Esophagus (Food Tube): The esophagus is a stretchy tube behind the trachea (windpipe) that carries food from the throat to the stomach. It does not digest food or absorb nutrients but helps move food along with mucus. There are two sphincters (muscle valves) that control the flow of food in the esophagus: 1. Upper Esophageal Sphincter: Relaxes when you swallow, allowing food to enter the esophagus. 2. Lower Esophageal Sphincter: Relaxes to let food move from the esophagus to the stomach. Peritoneum - Simplified The peritoneum is the largest smooth membrane in the body. It surrounds and protects organs in the abdominal area, just like how the pericardium surrounds the heart and the pleura surrounds the lungs. Peritoneal Cavity: This is the space between two layers of the peritoneum that contains a smooth fluid to reduce friction. There are two types of peritoneum: 1. Parietal Peritoneum: Lines the walls of the abdomen. 2. Visceral Peritoneum: Covers some of the abdominal organs. Peritoneal Folds - Structures That Hold Organs in Place The peritoneum also forms folds that help hold organs together and in place. These folds contain blood vessels, lymphatic vessels, and nerves. 1. Mesentery: A fold that holds the small intestine to the back wall of the abdomen. It lets the intestines move freely while still being supported. 2. Falciform Ligament: This connects the liver to the front of the abdomen and the diaphragm. 3. Omentum: A fatty fold of the peritoneum. o Greater Omentum: A large fold that hangs down like an apron over the stomach and intestines. o Lesser Omentum: Connects the stomach and small intestine to the liver. Stomach The stomach is a key organ in digestion and is divided into four parts: 1. Cardia: The top part where food enters from the esophagus. 2. Fundus: The upper storage area where digestion begins. 3. Body (Antrum): The main part of the stomach with folds called rugae. 4. Pylorus: The lower part connected to the small intestine through the pyloric sphincter. The stomach has four types of gastric glands: 1. Peptic or Chief Cells: Release pepsinogen (inactive enzyme) and gastric lipase (helps digest fats). 2. Parietal Cells: Produce hydrochloric acid (HCL), which: o Activates pepsinogen to pepsin (helps break down proteins). o Kills germs in food. o Helps absorb vitamin B12. 3. Mucous Cells: Secrete mucus to protect the stomach lining. 4. Enteroendocrine Cells: Release gastrin, a hormone that helps release stomach acid and enzymes. The combination of food and gastric juices creates a liquid called chyme. Digestion in the Stomach Peristalsis: The stomach moves food in waves every 15-25 seconds to mix it. After eating, the stomach takes 2-6 hours to empty:  o Carbs leave quickly. o Proteins take longer. o Fats take the longest. Small Intestine - Main Job: Digestion and Nutrient Absorption (90% of it) The small intestine starts at the pyloric sphincter (where food exits the stomach) and ends at the cecum (the beginning of the large intestine). It's about 10 feet long. There are 3 parts and 1 sphincter in the small intestine: 1. Duodenum (first part) o The smallest part of the small intestine. o Important for mixing bile and digestive enzymes to break down food: § Common bile duct: From the liver and gallbladder, it delivers bile, which helps break down fats. § Pancreatic duct: From the pancreas, it releases enzymes that help break down carbs, proteins, and fats (e.g., amylase, trypsin, and lipase). 2. Jejunum (middle part) o Where most nutrient absorption happens. 3. Ileum (last part) o Has the ileocecal sphincter that controls the movement of food into the cecum (start of the large intestine). Large Intestine - Main Jobs: Absorb Remaining Water, Make Feces, and Expel Waste The large intestine is about 5 feet long. Its main jobs are to: 1. Absorb water left from food. 2. Make certain vitamins. 3. Form feces (poop). 4. Expel feces from the body. It’s made up of 3 parts: 1. Cecum (first part) o The start of the large intestine. o Has the vermiform appendix, which plays a role in immunity (has lots of immune tissue). 2. Colon (middle part) o Has 4 sections: § Ascending colon: Goes up the right side of the abdomen. § Transverse colon: Goes across the abdomen. § Descending colon: Goes down the left side of the abdomen. § Sigmoid colon: Curves into the left lower part of the abdomen. 3. Rectum (last part) o About 8 inches long. o Contains: § Anal canal: The last part of the rectum.  § Internal anal sphincter: Smooth muscle (involuntary). § External anal sphincter: Skeletal muscle (voluntary). Feces After food has been in the large intestine for 3-10 hours, the intestine absorbs water, making the food thicker and forming feces. Feces consists of: o Water o Inorganic salts o Dead cells from the digestive tract o Bacteria o Leftover food and undigested material. Defecation - Getting Rid of Waste Defecation is the process of eliminating feces from the body. Liver - The Body’s Chemical Factory The liver is located below the diaphragm, mostly on the right side of your body. It makes bile, a yellowish-green liquid that helps with digestion. What’s in Bile? Bile is mostly water and contains: o Bile salts: Help break down large fat molecules into smaller fat droplets. o Cholesterol. o Lecithin: A type of fat. o Bile pigments (like bilirubin): Give bile its color. o Ions (like sodium and potassium). Bile is both: Excretory (helps get rid of waste). Digestive (helps break down fats). Bile enters small channels in the liver and then travels through the common hepatic duct. Bilirubin: Waste from Red Blood Cells When old red blood cells break down, they release: o Iron and globin (protein part) get recycled. o Bilirubin, a waste product, is excreted into bile. Bilirubin is broken down in the intestine, and part of it gives feces their color. Liver Functions - What It Does 1. Carbohydrate Metabolism - Keeps blood sugar at normal levels: o Turns other sugars (like fructose and galactose) into glucose. o Turns excess glucose into fat for storage. o Stores glucose as glycogen when blood sugar is high. o Breaks down glycogen into glucose when blood sugar is low. o Makes glucose from amino acids when needed. 2. Protein Metabolism - Helps process proteins. 3. Removes drugs and hormones from the body.  4. Makes bile. 5. Makes bile salts. 6. Stores vitamins and minerals (like A, D, E, K, B12, and iron). 7. Phagocytosis - Eats up and breaks down harmful particles or old cells. 8. Activates vitamin D. 9. Fat Metabolism - Helps process fats. Gall Bladder - Bile Storage The gallbladder stores and concentrates bile until the body needs it. When food enters the small intestine, the gallbladder contracts and pushes bile through the cystic duct, into the common bile duct, and into the small intestine. Bile enters the small intestine through the common bile duct, and it leaves the liver through the common hepatic duct. Pancreas - The Digestive Helper The pancreas is located behind the stomach and connects to the duodenum (the first part of the small intestine) through 2 ducts. The pancreas is made of two main types of cells: 1. Pancreatic Islets (Islets of Langerhans): These make up about 1% of the pancreas and are part of the endocrine system. They produce hormones that regulate blood sugar: § Alpha cells: Release glucagon when blood sugar is low, raising blood sugar. § Beta cells: Release insulin when blood sugar is high, lowering blood sugar. § Delta cells: Release a hormone to slow down growth hormone when blood sugar is normal. § F cells: Release pancreatic polypeptide, which helps control pancreas secretions. 2. Acini: These make up 99% of the pancreas and are part of the exocrine system. They produce digestive enzymes (called pancreatic juice) to break down food in the small intestine. What’s in Pancreatic Juice? Water, sodium bicarbonate (helps neutralize stomach acid), and digestive enzymes: o Amylase: Breaks down carbohydrates (sugars). o Trypsin, Chymotrypsin, and Carboxypeptidase: Break down proteins. o Lipase: Breaks down fats. o Ribonuclease and Deoxyribonuclease: Break down nucleic acids (DNA and RNA). Health Issues Related to the Pancreas 1. Gallstones: o Form from cholesterol crystals in the gallbladder (where bile is stored).  o Can block bile flow, causing pain, jaundice (yellow skin), and discomfort. 2. Cirrhosis (Scarring of the Liver): o Happens when liver cells are replaced by scar tissue due to long-term damage (like from alcohol or infections). o Symptoms include jaundice, swelling in legs, bleeding, and sensitivity to medications. 3. Gastric Ulcer: o Sores in the stomach lining, caused by a lack of mucus protection and too much acid. o Can be triggered by stress, certain foods, alcohol, aspirin, or smoking. 4. Appendicitis (Appendix Inflammation): o Occurs when the appendix gets blocked, causing pain, nausea, and vomiting. o It usually starts with pain near the belly button and moves to the lower right abdomen. 5. Hepatitis (Liver Inflammation): o Caused by viruses, alcohol, or drugs. o There are 3 types: § Hepatitis A: Spread by contaminated food or water. § Hepatitis B: Spread by sexual contact, shared needles, or contaminated blood products. § Hepatitis C: Mainly spread by blood transfusions or needle sharing.