Week 11 Content Flashcards
The Respiratory System
Facilitate gas exchange
Delivers oxygen to bloodstream, remove carbon dioxide from tissues
Filters, warms air, protects lungs
Regulates pH
Voice
Key Components
Upper respiratory tract: Nose, nasal cavities, pharynx, and larynx
Lower respiratory tract: Trachea, bronchi, bronchioles, and alveoli
Respiratory System Zones
- Conducting zone: Respiratory passageways that transport air
- Respiratory zone: Site of gas exchange in the lungs
Key Structures of the Respiratory System
Nose, nasal cavity, and paranasal sinuses
Pharynx, larynx, and trachea
Bronchi and smaller branches
Lungs and alveoli
Nose
Airway for respiration
Moistens, warms, and filters air
Resonating chamber for speech
Houses olfactory receptors
External Nose Skeletal Framework Diagram
Nasal Cavity Structures
External nares (nostrils): Anterior openings
Divided by nasal septum
Posterior nasal apertures (choanae): Posterior openings
Continuous with nasopharynx
Nasal Mucosa
- Olfactory mucosa: Roof of nasal cavity, has olfactory receptors
- Respiratory mucosa: Lines nasal cavity, filters, warms, and humidifies air
Respiratory Mucosa
Goblet cells secrete mucus
Cilia move mucus and contaminants to pharynx
Swallowed and digested
Sensory nerves (trigeminal nerve; CN V) supply the mucosa
Nasal Conchae (Turbinates)
Curved bones regulating airflow
Superior and middle conchae: Part of the ethmoid bone
Inferior conchae: Separate bones, project from lateral nasal wall
Functions of Nasal Conchae
Increase surface area
Create turbulent airflow
Filter, warm, and humidify air
Trap particles and pathogens in mucus
Conserve moisture and heat during exhalation
Paranasal Sinuses
- Frontal sinus
- Maxillary sinus
- Sphenoid sinus
- Ethmoid sinus
Paranasal Sinuses
Frontal sinus: Frontal bone, lighten skull and enhance voice resonance
Maxillary sinus: Maxillary bones, largest, drain mucus, affect voice tone
Sphenoid sinus: Sphenoid bone, air reservoir, influence voice quality
Ethmoid sinus: Ethmoid bone, warm, filter, and moisten air
Pharynx
Funned-shaped passageway
Connects nasal cavity to mouth
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
Above food entry
Air passage only, closed during swallowing
Uvulva moves superiorly to block it
Continuous with nasal cavity
Features of the Nasopharynx
Pharyngeal tonsil (Adenoids): Posterior wall, destroys inhaled pathogens
Auditory tube opening: Connects middle ear to nasopharynx, pressure balance
Tubal tonsil: Surrounds auditory tube, protects against infection
Oropharynx
Fauces: Arched opening from soft palate to epiglottis
Palatine tonsils: Lateral walls of fauces
Lingual tonsils: Posterior surface of tongue
Laryngopharynx
Passage for food and air
Continuous with esophagus (food) and larynx (air)
Extends to inferior cricoid cartilage boundary
Pharynx Diagram
Larynx
Voice box, C4-C6
Attaches to hyoid superiorly
Opens into laryngopharynx
Transitions into trachea
Controlled by vagus nerve (Cranial nerve X)
Larynx Functions
Voice production, houses vocal cords
Maintains open airway
Routes air and food
Superior opening closed during swallowing, open during breathing
Larynx Structure
Single cartilages
1. Thyroid cartilage
2. Cricoid cartilage
3. Epiglottis
Paired cartilages
1. Arytenoid cartilage
2. Corniculate cartilages
3. Cuneiform cartilages
Single Cartilages of the Larynx
Thyroid cartilage: Largest, forms laryngeal prominence (Adam’s apple)
Cricoid cartilage: Ring-shaped, connects larynx to trachea
Epiglottis: Covers laryngeal opening during swallowing
Paired Cartilage of the Larynx
Arytenoid cartilages: Anchor vocal cords
Corniculate cartilages: Small, horn-shaped, top of arytenoids
Cuneiform cartilages: Rod-shaped, structural support
Anterior View of Larynx Diagram
Vocal Ligaments of Larynx
Vocal folds (true): Produce sound, vibrate with air
Vestibular folds (false): No sound production, close larynx during swallowing
Structures of the Larynx
Rima glottidis: Opening between vocal folds for air
Glottis: Vocal folds and the rima glottidis together
Voice Production
Vocal fold length changes pitch
- Longer/loose = Lower pitch
- Shorter/tight = Higher pitch
Volume depends on air force
- Stronger airflow = Louder sound
Trachea
Windpipe, connect larynx to primary bronchi
Descends into mediastinum
C-shaped cartilage rings keep airway open
Trachealis keeps trachea open on posterior side
Cross Section of Trachea and Esophagus Diagram
Trachea
Ends at the carina
Ridge at the tracheal bifurcation (where it splits into 2 pathways)
Splits into right and left primary bronchi
Bronchial Tree
Conducting zone
Highly branched respiratory passageways
Primary bronchi: Largest, right is wider and shorter than left
Branching of Bronchial Tree Diagram
Bronchial Tree Branching
Secondary (lobar) bronchi: 3 on right, 2 on left
Tertiary (segmental) bronchi: Further divisions, deliver air into bronchopulmonary segments
Bronchioles in the Conducting Zone
Bronchioles: Small airways (<1 mm), smooth muscle
Terminal Bronchioles: Smallest conducting airways (<0.5 mm)
Changes in Bronchial Tree Structure
C-shaped rings transition to cartilage plates
Smooth muscle regulates airway size
Sympathetic stimulation: Airways widen
Parasympathetic stimulation: Airways constrict
Respiratory Zone
Respiratory bronchioles: Branch from terminal bronchioles, gas exchange occurs
Alveolar ducts: Connect respiratory bronchioles to alveoli
Alveolar sacs: Clusters of alveoli, primary site of gas exchange
Alveoli
~400 million
Surface area for gas exchange
~ 140m^2
Type 1 Alveoli
Main site for gas exchange (O2 and CO2 diffusion)
Line alveolar walls
Type 2 Alveoli
Produce and secrete surfactant
- Reduces surface tension
- Aid lung expansion
- Prevents collapse
Alveolar Macrophages
Immune cells that remove inhaled particles and pathogens
Move from alveoli to bronchi
Cilia move macrophages to pharynx for removal
Respiratory Membrane Diagram
Features of Alveoli
Surrounded by elastic fibers
Interconnect by alveolar pores
Internal surfaces allow macrophage movement
Dense network of capillaries surrounds alveolus
Gross Anatomy of the Lungs
Apex: Superior tip
Base: Concave inferior surface
Hilum: Indentation on where vessels, bronchi, and nerves enter/exit
Root: Structures at hilum
Gross Anatomy of Left and Right Lung
Left lung
- Superior and inferior lobes
- Oblique fissure
- Cardiac notch: Depression that accommodates the heart
Right lung: Superior, middle, and inferior lobes
- Oblique and horizontal fissure
Bronchopulmonary Segments
Functional and anatomical unit of lung
Has its own tertiary bronchi, pulmonary artery, and pulmonary vein
Efficient air distribution, gas exchange, and localized treatment
Bronchopulmonary Segments of Right Lung
Superior lobe
- Apical
- Posterior
- Anterior
Middle lobe
- Lateral
- Medial
Inferior lobe
- Superior basal
- Anterior basal
- Medial basal
- Lateral basal
- Posterior basal
Bronchopulmonary Segments of Left Lung
Superior lobe
- Apicoposterior
- Anterior
- Lingular (Superior, Inferior)
Inferior lobe
- Superior
- Anterior basal
- Medial basal
- Lateral basal
- Posterior basal
Bronchopulmonary Segments Diagram
Blood Supply of the Lungs
Pulmonary arteries: Deliver oxygen-poor blood to lungs
Pulmonary veins: Carry oxygenated blood to heart
Innervation of the Lungs
Parasympathetic: Bronchoconstriction and vasodilation
Sympathetic: Bronchodilation and vasoconstriction
Visceral sensory: Pain, stretch, and irritation
Pleurae
Double-layered sac around each lung
Parietal pleura (outer)
Visceral pleura (inner)
Pleural cavity: Space between, contains pleural fluid
Function of Pleurae
Divide the thoracic cavity into compartments
- Central mediastinum (heart, great vessels)
- Two pleural compartments (lungs)
Reduce friction, regulate pressure, protect organs
Location of Lungs and Pleural Cavities
In thoracic cage
- Anterior: Lungs between clavicle and ribs 7-8, pleura ends at rib 10
- Posterior: Lungs reach rib 10, pleura ends between ribs 10-12
Four Processes of Respiration
- Pulmonary ventilation
- External respiration
- Transport of respiratory gases
- Internal respiration
Pulmonary Ventilation
Air movement in and out of lungs
Inhalation: Air enters
Exhalation: CO2 expelled
Thoracic cavity volume changes lung pressure through intercostal contraction/relaxation
External Respiration
Gas exchange between lungs and blood
- Oxygen diffuses into blood
- CO2 diffuses into alveoli to be exhaled
Driven by partial pressure gradients
Transport of Respiratory Gases
O2 carried by hemoglobin in red blood cells, some in plasma
CO2 transported as bicarbonate in plasma
Internal Respiration
Gas exchange between blood and tissues
O2 diffuses from blood to tissues
CO2 diffuses from tissues to blood
Driven by partial pressure differences (High to low)
The Mechanisms of Ventilation
Two phases of pulmonary ventilation
- Inspiration (Inhalation)
- Expiration (Exhalation)
Inspiration
Thoracic cavity volume increases
Diaphragm flattens, moves downward
Intercostal muscles contract, lifting ribs, expand chest, reduces internal pressure
Deep Inspiration
Scalenes: Elevate first 2 ribs
Sternocleidomastoid: Lifts sternum
Pectoralis Minor: Elevate ribs
Quadratus lumborum: Stabilizes lower rib cage
Erector spinae: Extends the back
Expiration
Quiet expiration: Passive, relaxed inspiratory muscles and diaphragm moves upward, decreases thoracic volume
Forced expiration: Active contraction of internal/external obliques and transversus abdominis
Inspiration and Expiration Diagram
Neural Control of Ventilation
Ventral respiratory group (VRG)
- In reticular formation in the medulla oblongata
Neurons generate respiratory rhythm
Chemoreceptors detect blood oxygen changes
- Central chemoreceptors in medulla monitor CO2
- Peripheral chemoreceptors monitor O2 in blood (aortic and cardiac bodies)
Bronchial Asthma
Chronic airway inflammation
Bronchoconstriction and mucus production narrow airways
Allergens, cold air, stress
Wheezing, shortness of breath, chest tightness, coughing
Cystic Fibrosis (CF)
Thick mucus buildup obstructs airways
Inherited disorder
Chronic cough, lung infections, inflammation, difficulty breathing, poor growth
Reduced life expectancy
Chronic Obstructive Pulmonary Disease (COPD)
Prolonged exposure to irritants
Chronic cough, shortness of breath, wheezing, and increased mucus
Emphysema (alveolar damage) and chronic bronchitis (airway inflammation)
Pneumonia
Lung infection causes inflammation
Fluid or pus buildup in alveoli
Cough, fever, shortness of breath, chest pain, fatigue
Pneumothorax
Air in pleural space causes lung collapse
Disrupts negative pressure
Sudden chest pain, shortness of breath, rapid breathing
Pulmonary Embolism
Pulmonary artery blockage from blood clot
Sudden shortness of breath, chest pain, rapid heart rate, coughing up blood
Impaired blood flow, reduced oxygen exchange
Lung Development
1/6 of alveoli present at birth
Smoking impairs lung development, prevents further alveoli formation
Aging Respiratory System
Fewer nasal glands, dryness, thicker mucus
Stiffened thoracic wall, reduced lung elasticity
Decreased blood oxygen levels
Digestive System
Group of organs that break down food, absorb nutrients, and eliminate waste
Provide energy and nutrients for cellular functions
Groups of Digestive Organs
- Alimentary canal (GI Tract)
- Accessory digestive organs
Alimentary Canal
Continuous pathway that food travels through
Mouth, pharynx, and esophagus
Stomach, small intestine, and large intestine
Accessory Digestive Organs
Aid digestion chemically with enzymes, bile, or mechanically
Connected to alimentary canal
Includes teeth, tongue, salivary glands, gall bladder, liver, and pancreas
Abdominal Regions
Abdomen divided into 9 regions by 4 lines
Two vertical lines: Midclavicular lines
Two horizontal lines: Subcostal plane (superior), transtubercular plane (inferior)
Organs of the Abdominal Regions Diagram
Abdominal Quadrants
Peritoneal Cavity and Peritoneum
Peritoneum: Thin serous membrane
1. Visceral peritoneum: Covers digestive organs
2. Parietal peritoneum: Lines inner body wall
Peritoneal cavity: Space between layers, filled with serous fluid
Mesentery
Double layer of peritoneum
- Holds organs in place
Fat storage
Pathway for circulatory vessels and nerves
Ventral Mesenteries
Falciform ligament: Connects liver to abdominal wall, stability
Lesser omentum: Connects liver to lesser curvature of stomach, pathway for blood vessels and ducts
- ie; Portal vein, bile duct
Dorsal Mesenteries
Greater omentum: Connects greater curvature of stomach to abdominal wall
Transverse mesocolon: Stabilizes transverse colon
Sigmoid mesocolon: Connects sigmoid colon to pelvic wall
Digestive Processes Overview
- Ingestion
- Propulsion
- Mechanical breakdown
- Digestion
- Absorption
- Defecation
Ingestion
Taking in food or drink
Begins in the mouth
Propulsion
Wave-like muscular contractions that propel food
Swallowing
Peristalsis
Adjacent segments of the alimentary canal relax and contract
Mechanical Breakdown
Prepares food for chemical digestion
1. Chewing (mouth)
2. Churning (stomach)
3. Segmentation (intestine)
Chewing (Mastication)
Breaks food into smaller pieces
Shearing, grinding, crushing
Easier to swallow
Increased surface area for enzymes to act
Churning
Mixes food with gastric juices, forms chyme
Propulsion: Peristalsis moves chyme toward the pyloric sphincter
Retropulsion: Chyme moves backward if sphincter remains closed
Segmentation
Rhythmic local contractions of intestine
Mixes food with digestive juices
Digestion
Chemical breakdown of food
Mouth: Salivary enzymes begin carbohydrate breakdown
Stomach: Gastric acids and enzymes break down protein
Small intestine: Most chemical digestion here with bile and pancreatic enzymes
Absorption
Nutrients transported from digestive tract into the bloodstream
- Mostly in small intestine
Villi increase surface area
Defecation
Elimination of indigestible substances and waste products as feces
Forms in rectum
Expelled from anus through anal canal
Digestive Processes Diagram
Smooth Muscle
In organ walls
Elongated fibers, single central nucleus
- Longitudinal layer: Fibers parallel to organ’s long axis
- Circular layer: Deeper, fibers encircle organ
Smooth Muscle Contraction
Contracts and relaxes
- 30x slower than skeletal muscle
- Fatigue-resistant
Maintains tone in arteries and visceral organs
Low energy demands
- Few mitochondria required
Innervation of Smooth Muscle
Controlled by autonomic nervous system
- Few fibers per sheet
- Single-unit innervation: Signals spread through gap junctions, entire sheet contracts
- Multi-unit innervation: Each smooth muscle cell receives individual nerve input
Varicosities
Swellings along autonomic nerve fibers
Contain vesicles, release neurotransmitters
Coordinate smooth muscle activity
Control regional contraction
Innervation
Sympathetic fibers: Slow digestion
Parasympathetic fibers: Enhance digestion
Visceral sensory fibers: Relay status to the CNS
Mouth
Oral cavity lined with mucosa
Boundaries
- Anterior: Teeth, gums, lips
- Posterior: Oropharynx
- Lateral: Cheeks
- Superior: Palate
- Inferior: Tongue, floor of mouth
Mucosal Membrane
Covers oral cavity
- Protects underlying tissues
Detects stimuli (temperature, touch, pain)
Maintains moisture through glandular secretions
Lips and Cheeks
Oral labia, orbicularis oris
Cheeks supported by buccinator
- Protects internal structures
- Aids chewing and speech
Oral vestibule: Space between the lips and teeth
Anatomy of the Mouth
Gingivae: Gums, surround and supports the teeth
Labial fenulum: Connects lips to gums
Lingual frenulum: Connects tongue to floor of mouth
Palate
Roof of mouth
Hard palate: Bony, anterior, for tongue pressure during chewing
Soft palate: Muscular, posterior, elevates to close nasopharynx when swallowing
Palatine raphe: Midline ridge of hard palate
Fauces (Throat)
Palatoglossal arches: Anterior, connects soft palate to tongue
Palatopharyngeal arches: Posterior, connects soft palate to pharynx
Key Structures of Oral Cavity
Palatine tonsils: Lateral fauces, trap and filter pathogens
Lingual tonsil: Base of tongue, protect against ingested pathogens
Uvula: Hangs from soft palate; prevents food from entering nasal cavity
Mouth Diagram
Tongue
Interlacing fascicles of skeletal muscle
- Involved in chewing, swallowing and speech
Intrinsic muscles: Within tongue, control shape and movement
Extrinsic muscles: Attached externally, control position
Intrinsic Tongue Muscles
Superior longitudinal: Elevates and curls tip, aids speech and swallowing
Inferior longitudinal: Lowers and retracts tip
Vertical: Flattens, broadens, and controls shape
Transverse: Narrows and elongates, aids speech and swallowing
Superior Surface of the Tongue
Terminal sulcus: Divides tongue into oral cavity (anterior) and oropharynx (posterior)
Median sulcus: Central groove on tongue surface
Posterior third: In oropharynx, covered by lingual tonsil
Teeth Overview
Deciduous teeth: 20, appear at 6 months
Permanent teeth: 32, emerge during childhood
Dental formula: 2I, 1C, 2P, 3M
- 2 incisors, 1 canine, 2 premolars, 3 molars
Deciduous Teeth Diagram
Permanent Teeth Diagram
Nerves of the Teeth
Trigeminal nerve (CN V)
Upper teeth: Superior alveolar nerves (maxillary branch)
Lower teeth: Inferior alveolar nerves (mandibular branch)
Vessels of the Teeth
Upper teeth: Superior alveolar arteries (branches of maxillary artery)
Lower teeth: Inferior alveolar arteries
Tooth Structure
Crown: Visible part above gumline
Neck: At gumline, where crown meets root
Root: Below gumline, anchored into mandible, contains root canal
Tooth Composition
Enamel: Hard, white outer layer
Dentin: Yellow, bone-like tissue beneath enamel
Pulp cavity: Soft tissue inside tooth with nerves and blood vessels
Apical foramen: Opening at root for nerves and blood vessels
Tooth Support Structures
Gingival Sulcus: Groove between tooth gum
Gingiva: Gum tissue, protects tooth
Periodontal ligament: Holds tooth socket, absorbs shock during chewing
Cementum: Covers root, anchors tooth to ligament
Salivary Glands
Produce saliva
- Lubricate and protects oral tissues
Contains enzymes for digestion
Break down carbohydrates in mouth
Major Salivary Glands
- Parotid glands: By ear, secrete serous fluid with amylase
- Submandibular glands: Along mandible, secrete serous fluid and mucous
- Sublingual glands: Under tongue, secrete mucous
Salivary Ducts
Release saliva from glands
Sublingual duct: Under tongue along sublingual fold
Submandibular duct: Beside lingual frenulum
Parotid duct: Near second upper molar, parallel to the zygomatic arch
Oropharynx and Laryngopharynx
Passages for air and food
Oropharynx: From soft palate to hyoid bone
Laryngopharynx: From hyoid esophageal opening
Pharyngeal Constrictors
External muscle layer
Superior, middle, and inferior pharyngeal constrictors
Vital for swallowing
Esophagus
Passages for food and liquid
Muscular tube from pharynx (C6) to stomach (T11)
Passes through diaphragm via esophageal hiatus
~25 cm long in adults
Cervical, thoracic, and abdominal parts
Lower Esophageal Sphincters
Junction of esophagus and stomach
Regulates food entry into stomach
Prevents acid reflux
Stomach
J-shaped organ, upper abdomen
~4 hour food storage
Mechanical digestion: Churns food into chyme
Chemical digestion: Hydrochloric acid and pepsin break down proteins
Absorbs alcohol and some medications
Regions of the Stomach
- Cardia: Where esophagus connects to stomach
- Fundus: Stores food, contains gastric glands
- Body: Forms chyme, contains gastric pits and glands
- Pylorus: Connects to duodenum
- Pyloric antrum: Grinds and mixes food
- Pyloric canal: Passage for chyme
Curvatures of the Stomach
Lesser curvature: Short, concave border from cardia to pylorus, attaches to lesser omentum
Greater curvature: Long, convex border from cardia to pylorus, attaches to greater omentum
Gastric Emptying
Pyloric sphincter opens into duodenum
Regulates stomach emptying and pace of digestion
Layers of the Stomach
Covered by serosa
Muscularis externa
1. Longitudinal layer (outer)
2. Circular layer (middle)
3. Oblique layer (inner, unique to stomach)
Mucosa: Contains gastric glands and mucous cells, lined with rugae
Small Intestine
Longest portion of alimentary canal
~ 6 meters
Site of most enzymatic digestion and absorption
- Duodenum
- Jejunum
- Ileum
Duodenum
First and shortest section (~25 cm, C- shaped)
Main site of chemical digestion
Receives enzymes from main pancreatic duct and common bile duct
Neutralizes stomach acid with bicarbonate ions
Jejunum
Middle section (~2 meters)
- Thicker, more vascular
Absorbs carbohydrates, proteins, and fats
Has circular folds and villi to increase surface area
Ileum
Final section (~3.6 meters)
Thinner, less vascular, fewer folds than jejunum
Absorbs vitamin B12 and bile salts
Contains Peyer’s patches
Innervation of the Small Intestine
Parasympathetic fibers from vagus nerve (CN X)
- Stimulates motility and secretion
Sympathetic fibers from thoracic splanchnic nerves
- Inhibits digestion
Large Intestine
Absorb water and electrolytes
Small amount of digestion by bacteria
Peristalsis moves feces to rectum
Temporary waste storage
- Fermentation by gut bacteria
Gross Anatomy of Large Intestine
- Cecum
- Appendix
- Colon (ascending, transverse, descending, sigmoid)
- Rectum
- Anal canal
Features of Large Intestine
Teniae coli: Muscle bands for peristalsis
Haustra: Pouches for expansion and contraction
Epiploic appendages: Fat-filled pouches
Cecum
Beginning of large intestine
In lower abdomen, after ileocecal valve
Receives chyme, widest part of large intestine
Absorbs water and salts
Bacterial fermentation
Appendix
Finger-like outpouching of cecum, lower right abdomen
Contains lymphatic tissue
Regulates gut bacteria, supports immune function
Often removed after appendicitis
Colon
Absorbs water and salts from undigested material
Compacts waste
Houses bacteria that produce vitamins and digest carbohydrates
Key Segments of Colon
Ascending colon: Upward, right side
Transverse colon: Horizontal from right to left colic (splenic) flexure
Descending colon: Downward, left side
Sigmoid colon: S-shaped, connects to the rectum, stores feces
Rectum
Transition between sigmoid colon and anal canal
Descends along inferior sacrum
Holds feces before elimination
Transports feces to anal canal from excretion
Thick, muscular walls with stretch receptors
Anal Canal
Final large intestine segment (~3-4 cm)
Release feces
Internal anal sphincter: Involuntary smooth muscle
External anal sphincter: Voluntary skeletal muscle
Unique Features of Anal Canal
Anal columns: Vertical mucosal folds with vessels, cushion canal during defecation
Anal valves: Folds at column junctions
Anal sinuses: Secrete mucus for lubrication
Vessels of the Large Intestine
First half: Superior mesenteric artery
Distal half: Inferior mesenteric artery
Process of Digestion Diagram
Liver
Largest gland, vital for digestion, metabolism, and detoxification
Produces bile to emulsify fats
Performs metabolic functions
Hepatocyte: Functional cells of the liver
Liver Structures
Left lobe: Small, separated by falciform ligament
Caudate lobe: Posterior, near inferior vena cave
Right lobe: Large, extends toward diaphragm
Quadrate lobe: Small, inferior, near gallbladder
Portal Triad
- Bile duct: Carries bile to gallbladder or duodenum
- Hepatic portal vein: Carries nutrient-rich blood from GI tract
- Hepatic artery: Supplies oxygenated blood to liver
Gallbladder
Beneath liver, right upper quadrant
~7-10 cm long, holds 30-50 ml bile
Concentrates and expels bile into duodenum for fat digestion
Gallbladder Structure
Fundus: Rounded, faces forward
Body: Central portion
Neck: Narrow, leads to cystic duct
Cystic duct: Links gallbladder to common bile duct
Common bile duct: Carries bile from gallbladder and liver to duodenum
Pancreas
Dual function
Endocrine: Produces insulin and glucagon to regulate blood sugar
Exocrine: Acinar cells secrete digestive enzymes
Pancreas Regions
Head: Widest, in curve of duodenum
Body: Middle, contains most pancreatic tissue and ducts
Neck: Between head and body, anterior to mesenteric vessels
Tail: Tapered end near the spleen; endocrine
Key Pancreas Structures
Main pancreatic duct: Joins bile duct to form hepatopancreatic ampulla, empties into duodenum
Arterial supply: Hepatic, splenic, and superior mesenteric arteries
Digestive System Diagram
Gastroesophageal Reflux Disease (GERD)
Weak lower esophageal sphincter
- Stomach acid flows back into esophagus
Heartburn, irritation
Peptic Ulcers
Mucosal erosion in alimentary canal
Gastric ulcers: Pyloric region
Duodenal ulcers: Duodenum region
Caused by Helicobacter pylori and long-term NSAID use
Disorders of the Bowel
Inflammatory bowel disease
- Inflammation of intestinal wall, autoimmune
- Abdominal pain and diarrhea
Crohn’s disease
Ulcerative colitis
Constipation
Infrequent stool, affects the large intestine
Low fiber and dehydration
Discomfort, potential complications
Inflammatory Disorders of the Digestive System
Pancreatitis
- Inflamed pancreas
- Severe abdominal pain, nausea, vomiting, fever, rapid pulse
Viral hepatitis
- Inflamed liver
- Jaundice and flulike symptoms
- Major types (Hepatitis A, B, C)
Gallstones
Bile component imbalance
Sudden intense right upper quadrant pain, nausea, vomiting, fever, jaundice
Digestive System in Later Life
Digestive organ activity declines
Less digestive juices, fewer enzymes
Less efficient absorption, slower peristalsis
Dehydration
Increased risk of diverticulosis and digestive cancers
