exam 4

Functions of the Respiratory System

Absorbs O2 into blood, releases CO2, and houses structures involved in speech and smell receptors.

Nose

Inlet and outlet for air, includes nares (nostrils) and nasal cavity.

Nasal cavity

Space inside the nose partitioned into left and right chambers by the nasal septum.

Nasal Conchae

Ridges on the side walls of the nasal cavity that swirl inhaled air.

Functions of Nasal Conchae

Generate air turbulence to moisten, warm, and trap dust; lined with mucus membrane.

Paranasal Sinuses

Cavities surrounding the nasal cavity that help resonate speech sounds.

Pharynx

Also known as the throat, lined with mucous membrane and contains skeletal muscle.

Larynx

Voice box, lined with mucus membrane, contains the epiglottis and vocal folds.

Epiglottis

Flap of cartilage that covers the opening of the larynx during swallowing.

Vocal folds

Ligaments with skeletal muscles that vibrate to generate speech sounds.

How pitch is controlled in speech

By loosening or tightening of the vocal cords.

How volume is controlled in speech

By altering how much air is exhaled across the vocal cords.

Trachea

Windpipe, a 5 inch long tube lined with mucus membrane and cilia.

Lungs

Composed of bronchi, bronchioles, visceral pleura, and alveoli.

Alveoli

Microscopic air bulbs in the lungs, sites of gas exchange between airways and blood.

Type 1 Alveolar cells

Flat epithelial cells that are part of the alveolar wall.

Type 2 Alveolar cells

Secrete surfactant to prevent the alveoli from collapsing.

Infant Respiratory Distress Syndrome (IRDS)

Occurs when a baby lacks sufficient surfactant in their lungs.

Bronchioles

Tiny airways that are smaller than 1 mm and lack cartilage rings.

Bronchocontriction

Contraction of smooth muscle in bronchi and bronchioles leading to reduced airway diameter.

Bronchodilation

Relaxation of smooth muscle in bronchi and bronchioles increasing airway diameter.

Primary Bronchi

Two large airways that branch off the trachea to each lung.

Secondary Bronchi

Branch off primary bronchi, connecting to lobes of each lung.

Tertiary Bronchi

Branch off secondary bronchi, further dividing in the lungs.

Visceral Pleura

Membrane covering the lungs, reduces friction with the chest cavity.

Parietal Pleura

Membrane lining the chest cavity, similar to the visceral pleura.

Ventilation

Gas exchange between the lungs and atmosphere; involves inspiration and expiration.

Inspiration

Breathing in air, causing the diaphragm and external intercostals to contract.

Forced Inspiration

Deep breathing involving additional muscles for greater increase in lung volume.

Exhalation

Breathing out air, occurring when diaphragm and external intercostals relax.

Forced expiration

Forcibly blowing air out of the lungs, involving muscles in the abdomen and intercostals.

Asthma

Disease characterized by bronchoconstriction and airway inflammation.

COPD

Chronic Obstructive Pulmonary Disease, includes bronchitis and emphysema.

Bronchitis

Chronic airway inflammation caused by infection or pollutants.

Emphysema

Loss of lung elasticity due to destroyed elastic tissue and fused alveolar walls.

Pneumonia

Inflammation of alveoli usually caused by infection.

Conscious Control of Ventilation

Ability to mentally control skeletal muscles involved in breathing.

Unconscious Control of Ventilation

Regulated by the respiratory center in the brain stem.

Hyperventilation

Increased depth and frequency of breathing due to low O2 or high CO2.

Hypoventilation

Slow and shallow breathing due to high O2 or low CO2.

O2 transport in blood

1% of O2 dissolved in plasma, 99% bound to hemoglobin.

Factors influencing oxygen hemoglobin binding

Heat, pH, CO2 levels affect the release of O2 from hemoglobin.

How CO2 is transported through the blood

7% dissolved, 23% bound to hemoglobin, 70% converted to bicarbonate.

Carbon Monoxide Poisoning

CO binds to hemoglobin more effectively than O2, leading to hypoxia.

Symptoms of CO poisoning

Headache, dizziness, confusion, fatigue, nausea, loss of consciousness.

Breathing at High Altitude

Less oxygen is absorbed, body compensates by increasing RBC production.

Altitude Sickness

Mild hypoxia caused by high elevation; symptoms include headache and fatigue.

Digestive System functions

Mechanical digestion, chemical digestion, and absorption.

Digestive tract

Tube extending from mouth to anus with four layers.

Mucosa

Inner layer of the digestive tract, varies in epithelial type along its length.

Submucosa

Loose connective tissue layer containing blood and lymphatic vessels.

Muscularis Externa

Muscular layer with both skeletal and smooth muscle; involved in peristalsis.

Peristalsis

Coordinated contraction of smooth muscle to move material through the tract.

Serosa

Outer layer covering the digestive organs, composed of a slick membrane.

Mouth

Includes structures involved in mechanical and chemical digestion.

Mechanical Digestion in the Mouth

Chewing (mastication) mixes food with saliva to form a bolus.

Saliva

Produced by salivary glands, contains water, mucus, amylase, and bicarbonate.

Chemical Digestion in the Mouth

Carried out by salivary amylase which breaks down starches.

Absorption in the Mouth

Only small, hydrophobic molecules can be absorbed.

Pharynx

Throat; involved in swallowing, not much absorption occurs.

Esophagus

Gullet; primarily involved in swallowing.

Swallowing (Deglutition)

Process of moving the bolus from the mouth to the stomach through coordinated muscle actions.

Stomach

Lined with mucus, contains gastric juice for digestion.

Hydrochloric Acid (HCl)

Strong acid in gastric juice that denatures proteins.

Pepsin

Enzyme that breaks down proteins into smaller peptides in the stomach.

Gastric Lipase

Enzyme that breaks down fats in the stomach.

Chyme

Mixture of food, saliva, and gastric juices in the stomach.

GERD (Gastroesophageal Reflux Disease)

Caused by improper closure of the cardiac sphincter, leading to heartburn.

Small Intestine sections

Duodenum, jejunum, ileum; site of most chemical digestion and absorption.

Circular Folds

Large ridges in the small intestine that increase surface area.

Villi

Fingerlike structures in the small intestine that absorb nutrients.

Microvilli

Microscopic projections on villi that contain digestive enzymes.

Mechanical Digestion in the Small Intestine

Segmentations and peristalsis mix and move chyme.

Pancreatic Juice

Secreted into the duodenum to aid in digestion, contains multiple enzymes and bicarbonate.

Bile

Produced by the liver, helps emulsify fats in the duodenum.

Brush Border Enzymes

Digestive enzymes located on the microvilli of the small intestine.

Absorption in the Small Intestine

Most absorption occurs, including water, electrolytes, vitamins, and nutrients.

Large Intestine

Absorbs water and electrolytes, includes appendix and various colon sections.

Healthy Bacteria in Large Intestine

Contribute to digestion and reservoirs for microbial balance.

Haustra

Bulges along the length of the large intestine.

Haustral Churning

Contraction of haustra that promotes digestion and absorption.

Defecation

Reflex triggered by fecals build-up in the rectum.

Chemical Digestion in the Large Intestine

Carried out by bacteria that break down remaining sugars and amino acids.

Lactose Intolerance

Condition where lactose cannot be properly digested due to lack of lactase.

Absorption in the Large Intestine

Some nutrients and water are absorbed, including vitamins produced by bacteria.

Feces Composition

Includes undigested food, bacteria, and various waste products.

Smell of Feces

Derived from gases produced during fermentation of food in the large intestine.

Defecation Issues

Includes diarrhea and constipation, caused by movement issues of fecal matter.

Diarrhea

Rapid passage of feces leading to hydration issues.

Constipation

Slow movement of feces causing dryness and difficulty in defecation.

Fiber

Plant carbohydrates that cannot be digested but aid in bowel regularity.

Types of Fiber

Soluble fiber dissolves in water; insoluble fiber does not but aids in bulk.

Benefits of Fiber

Prevents constipation, promotes satiety, and can help lower cholesterol.

Healthy Diet Inclusion

Both soluble and insoluble fibers are beneficial in maintaining digestive health.