Week 11 Content Flashcards

(164 cards)

1
Q

The Respiratory System

A

Facilitate gas exchange

Delivers oxygen to bloodstream, remove carbon dioxide from tissues

Filters, warms air, protects lungs

Regulates pH

Voice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Key Components

A

Upper respiratory tract: Nose, nasal cavities, pharynx, and larynx

Lower respiratory tract: Trachea, bronchi, bronchioles, and alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Respiratory System Zones

A
  1. Conducting zone: Respiratory passageways that transport air
  2. Respiratory zone: Site of gas exchange in the lungs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Key Structures of the Respiratory System

A

Nose, nasal cavity, and paranasal sinuses

Pharynx, larynx, and trachea

Bronchi and smaller branches

Lungs and alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nose

A

Airway for respiration

Moistens, warms, and filters air

Resonating chamber for speech

Houses olfactory receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

External Nose Skeletal Framework Diagram

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Nasal Cavity Structures

A

External nares (nostrils): Anterior openings

Divided by nasal septum

Posterior nasal apertures (choanae): Posterior openings

Continuous with nasopharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Nasal Mucosa

A
  1. Olfactory mucosa: Roof of nasal cavity, has olfactory receptors
  2. Respiratory mucosa: Lines nasal cavity, filters, warms, and humidifies air
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Respiratory Mucosa

A

Goblet cells secrete mucus

Cilia move mucus and contaminants to pharynx

Swallowed and digested

Sensory nerves (trigeminal nerve; CN V) supply the mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Nasal Conchae (Turbinates)

A

Curved bones regulating airflow

Superior and middle conchae: Part of the ethmoid bone

Inferior conchae: Separate bones, project from lateral nasal wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Functions of Nasal Conchae

A

Increase surface area

Create turbulent airflow

Filter, warm, and humidify air

Trap particles and pathogens in mucus

Conserve moisture and heat during exhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Paranasal Sinuses

A
  1. Frontal sinus
  2. Maxillary sinus
  3. Sphenoid sinus
  4. Ethmoid sinus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Paranasal Sinuses

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Pharynx

A

Funned-shaped passageway

Connects nasal cavity to mouth

  1. Nasopharynx
  2. Oropharynx
  3. Laryngopharynx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Nasopharynx

A

Above food entry

Air passage only, closed during swallowing

Uvulva moves superiorly to block it

Continuous with nasal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Features of the Nasopharynx

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Oropharynx

A

Fauces: Arched opening from soft palate to epiglottis

Palatine tonsils: Lateral walls of fauces

Lingual tonsils: Posterior surface of tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Laryngopharynx

A

Passage for food and air

Continuous with esophagus (food) and larynx (air)

Extends to inferior cricoid cartilage boundary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Pharynx Diagram

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Larynx

A

Voice box, C4-C6

Attaches to hyoid superiorly

Opens into laryngopharynx

Transitions into trachea

Controlled by vagus nerve (Cranial nerve X)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Larynx Functions

A

Voice production, houses vocal cords

Maintains open airway

Routes air and food

Superior opening closed during swallowing, open during breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Larynx Structure

A

Single cartilages
1. Thyroid cartilage
2. Cricoid cartilage
3. Epiglottis

Paired cartilages
1. Arytenoid cartilage
2. Corniculate cartilages
3. Cuneiform cartilages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Single Cartilages of the Larynx

A

Thyroid cartilage: Largest, forms laryngeal prominence (Adam’s apple)

Cricoid cartilage: Ring-shaped, connects larynx to trachea

Epiglottis: Covers laryngeal opening during swallowing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Paired Cartilage of the Larynx

A

Arytenoid cartilages: Anchor vocal cords

Corniculate cartilages: Small, horn-shaped, top of arytenoids

Cuneiform cartilages: Rod-shaped, structural support

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Anterior View of Larynx Diagram
26
Vocal Ligaments of Larynx
Vocal folds (true): Produce sound, vibrate with air Vestibular folds (false): No sound production, close larynx during swallowing
27
Structures of the Larynx
Rima glottidis: Opening between vocal folds for air Glottis: Vocal folds and the rima glottidis together
28
Voice Production
Vocal fold length changes pitch - Longer/loose = Lower pitch - Shorter/tight = Higher pitch Volume depends on air force - Stronger airflow = Louder sound
29
Trachea
Windpipe, connect larynx to primary bronchi Descends into mediastinum C-shaped cartilage rings keep airway open Trachealis keeps trachea open on posterior side
30
Cross Section of Trachea and Esophagus Diagram
31
Trachea
Ends at the carina Ridge at the tracheal bifurcation (where it splits into 2 pathways) Splits into right and left primary bronchi
32
Bronchial Tree
Conducting zone Highly branched respiratory passageways Primary bronchi: Largest, right is wider and shorter than left
33
Branching of Bronchial Tree Diagram
34
Bronchial Tree Branching
Secondary (lobar) bronchi: 3 on right, 2 on left Tertiary (segmental) bronchi: Further divisions, deliver air into bronchopulmonary segments
35
Bronchioles in the Conducting Zone
Bronchioles: Small airways (<1 mm), smooth muscle Terminal Bronchioles: Smallest conducting airways (<0.5 mm)
36
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
37
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
38
Alveoli
~400 million Surface area for gas exchange ~ 140m^2
39
Type 1 Alveoli
Main site for gas exchange (O2 and CO2 diffusion) Line alveolar walls
40
Type 2 Alveoli
Produce and secrete surfactant - Reduces surface tension - Aid lung expansion - Prevents collapse
41
Alveolar Macrophages
Immune cells that remove inhaled particles and pathogens Move from alveoli to bronchi Cilia move macrophages to pharynx for removal
42
Respiratory Membrane Diagram
43
Features of Alveoli
Surrounded by elastic fibers Interconnect by alveolar pores Internal surfaces allow macrophage movement Dense network of capillaries surrounds alveolus
44
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
45
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
46
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
47
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
48
Bronchopulmonary Segments of Left Lung
Superior lobe - Apicoposterior - Anterior - Lingular (Superior, Inferior) Inferior lobe - Superior - Anterior basal - Medial basal - Lateral basal - Posterior basal
49
Bronchopulmonary Segments Diagram
50
Blood Supply of the Lungs
Pulmonary arteries: Deliver oxygen-poor blood to lungs Pulmonary veins: Carry oxygenated blood to heart
51
Innervation of the Lungs
Parasympathetic: Bronchoconstriction and vasodilation Sympathetic: Bronchodilation and vasoconstriction Visceral sensory: Pain, stretch, and irritation
52
Pleurae
Double-layered sac around each lung Parietal pleura (outer) Visceral pleura (inner) Pleural cavity: Space between, contains pleural fluid
53
Function of Pleurae
Divide the thoracic cavity into compartments - Central mediastinum (heart, great vessels) - Two pleural compartments (lungs) Reduce friction, regulate pressure, protect organs
54
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
55
Four Processes of Respiration
1. Pulmonary ventilation 2. External respiration 3. Transport of respiratory gases 4. Internal respiration
56
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
57
External Respiration
Gas exchange between lungs and blood - Oxygen diffuses into blood - CO2 diffuses into alveoli to be exhaled Driven by partial pressure gradients
58
Transport of Respiratory Gases
O2 carried by hemoglobin in red blood cells, some in plasma CO2 transported as bicarbonate in plasma
59
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)
60
The Mechanisms of Ventilation
Two phases of pulmonary ventilation - Inspiration (Inhalation) - Expiration (Exhalation)
61
Inspiration
Thoracic cavity volume increases Diaphragm flattens, moves downward Intercostal muscles contract, lifting ribs, expand chest, reduces internal pressure
62
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
63
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
64
Inspiration and Expiration Diagram
65
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)
66
Bronchial Asthma
Chronic airway inflammation Bronchoconstriction and mucus production narrow airways Allergens, cold air, stress Wheezing, shortness of breath, chest tightness, coughing
67
Cystic Fibrosis (CF)
Thick mucus buildup obstructs airways Inherited disorder Chronic cough, lung infections, inflammation, difficulty breathing, poor growth Reduced life expectancy
68
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)
69
Pneumonia
Lung infection causes inflammation Fluid or pus buildup in alveoli Cough, fever, shortness of breath, chest pain, fatigue
70
Pneumothorax
Air in pleural space causes lung collapse Disrupts negative pressure Sudden chest pain, shortness of breath, rapid breathing
71
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
72
Lung Development
1/6 of alveoli present at birth Smoking impairs lung development, prevents further alveoli formation
73
Aging Respiratory System
Fewer nasal glands, dryness, thicker mucus Stiffened thoracic wall, reduced lung elasticity Decreased blood oxygen levels
74
Digestive System
Group of organs that break down food, absorb nutrients, and eliminate waste Provide energy and nutrients for cellular functions
75
Groups of Digestive Organs
1. Alimentary canal (GI Tract) 2. Accessory digestive organs
76
Alimentary Canal
Continuous pathway that food travels through Mouth, pharynx, and esophagus Stomach, small intestine, and large intestine
77
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
78
Abdominal Regions
Abdomen divided into 9 regions by 4 lines Two vertical lines: Midclavicular lines Two horizontal lines: Subcostal plane (superior), transtubercular plane (inferior)
79
Organs of the Abdominal Regions Diagram
80
Abdominal Quadrants
81
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
82
Mesentery
Double layer of peritoneum - Holds organs in place Fat storage Pathway for circulatory vessels and nerves
83
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
84
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
85
Digestive Processes Overview
1. Ingestion 2. Propulsion 3. Mechanical breakdown 4. Digestion 5. Absorption 6. Defecation
86
Ingestion
Taking in food or drink Begins in the mouth
87
Propulsion
Wave-like muscular contractions that propel food Swallowing Peristalsis Adjacent segments of the alimentary canal relax and contract
88
Mechanical Breakdown
Prepares food for chemical digestion 1. Chewing (mouth) 2. Churning (stomach) 3. Segmentation (intestine)
89
Chewing (Mastication)
Breaks food into smaller pieces Shearing, grinding, crushing Easier to swallow Increased surface area for enzymes to act
90
Churning
Mixes food with gastric juices, forms chyme Propulsion: Peristalsis moves chyme toward the pyloric sphincter Retropulsion: Chyme moves backward if sphincter remains closed
91
Segmentation
Rhythmic local contractions of intestine Mixes food with digestive juices
92
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
93
Absorption
Nutrients transported from digestive tract into the bloodstream - Mostly in small intestine Villi increase surface area
94
Defecation
Elimination of indigestible substances and waste products as feces Forms in rectum Expelled from anus through anal canal
95
Digestive Processes Diagram
96
Smooth Muscle
In organ walls Elongated fibers, single central nucleus 1. Longitudinal layer: Fibers parallel to organ's long axis 2. Circular layer: Deeper, fibers encircle organ
97
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
98
Innervation of Smooth Muscle
Controlled by autonomic nervous system - Few fibers per sheet 1. Single-unit innervation: Signals spread through gap junctions, entire sheet contracts 2. Multi-unit innervation: Each smooth muscle cell receives individual nerve input
99
Varicosities
Swellings along autonomic nerve fibers Contain vesicles, release neurotransmitters Coordinate smooth muscle activity Control regional contraction
100
Innervation
Sympathetic fibers: Slow digestion Parasympathetic fibers: Enhance digestion Visceral sensory fibers: Relay status to the CNS
101
Mouth
Oral cavity lined with mucosa Boundaries - Anterior: Teeth, gums, lips - Posterior: Oropharynx - Lateral: Cheeks - Superior: Palate - Inferior: Tongue, floor of mouth
102
Mucosal Membrane
Covers oral cavity - Protects underlying tissues Detects stimuli (temperature, touch, pain) Maintains moisture through glandular secretions
103
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
104
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
105
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
106
Fauces (Throat)
Palatoglossal arches: Anterior, connects soft palate to tongue Palatopharyngeal arches: Posterior, connects soft palate to pharynx
107
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
108
Mouth Diagram
109
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
110
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
111
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
112
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
113
Deciduous Teeth Diagram
114
Permanent Teeth Diagram
115
Nerves of the Teeth
Trigeminal nerve (CN V) Upper teeth: Superior alveolar nerves (maxillary branch) Lower teeth: Inferior alveolar nerves (mandibular branch)
116
Vessels of the Teeth
Upper teeth: Superior alveolar arteries (branches of maxillary artery) Lower teeth: Inferior alveolar arteries
117
Tooth Structure
Crown: Visible part above gumline Neck: At gumline, where crown meets root Root: Below gumline, anchored into mandible, contains root canal
118
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
119
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
120
Salivary Glands
Produce saliva - Lubricate and protects oral tissues Contains enzymes for digestion Break down carbohydrates in mouth
121
Major Salivary Glands
1. Parotid glands: By ear, secrete serous fluid with amylase 2. Submandibular glands: Along mandible, secrete serous fluid and mucous 3. Sublingual glands: Under tongue, secrete mucous
122
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
123
Oropharynx and Laryngopharynx
Passages for air and food Oropharynx: From soft palate to hyoid bone Laryngopharynx: From hyoid esophageal opening
124
Pharyngeal Constrictors
External muscle layer Superior, middle, and inferior pharyngeal constrictors Vital for swallowing
125
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
126
Lower Esophageal Sphincters
Junction of esophagus and stomach Regulates food entry into stomach Prevents acid reflux
127
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
128
Regions of the Stomach
1. Cardia: Where esophagus connects to stomach 2. Fundus: Stores food, contains gastric glands 3. Body: Forms chyme, contains gastric pits and glands 4. Pylorus: Connects to duodenum - Pyloric antrum: Grinds and mixes food - Pyloric canal: Passage for chyme
129
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
130
Gastric Emptying
Pyloric sphincter opens into duodenum Regulates stomach emptying and pace of digestion
131
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
132
Small Intestine
Longest portion of alimentary canal ~ 6 meters Site of most enzymatic digestion and absorption 1. Duodenum 2. Jejunum 3. Ileum
133
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
134
Jejunum
Middle section (~2 meters) - Thicker, more vascular Absorbs carbohydrates, proteins, and fats Has circular folds and villi to increase surface area
135
Ileum
Final section (~3.6 meters) Thinner, less vascular, fewer folds than jejunum Absorbs vitamin B12 and bile salts Contains Peyer's patches
136
Innervation of the Small Intestine
Parasympathetic fibers from vagus nerve (CN X) - Stimulates motility and secretion Sympathetic fibers from thoracic splanchnic nerves - Inhibits digestion
137
Large Intestine
Absorb water and electrolytes Small amount of digestion by bacteria Peristalsis moves feces to rectum Temporary waste storage - Fermentation by gut bacteria
138
Gross Anatomy of Large Intestine
1. Cecum 2. Appendix 3. Colon (ascending, transverse, descending, sigmoid) 4. Rectum 5. Anal canal
139
Features of Large Intestine
Teniae coli: Muscle bands for peristalsis Haustra: Pouches for expansion and contraction Epiploic appendages: Fat-filled pouches
140
Cecum
Beginning of large intestine In lower abdomen, after ileocecal valve Receives chyme, widest part of large intestine Absorbs water and salts Bacterial fermentation
141
Appendix
Finger-like outpouching of cecum, lower right abdomen Contains lymphatic tissue Regulates gut bacteria, supports immune function Often removed after appendicitis
142
Colon
Absorbs water and salts from undigested material Compacts waste Houses bacteria that produce vitamins and digest carbohydrates
143
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
144
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
145
Anal Canal
Final large intestine segment (~3-4 cm) Release feces Internal anal sphincter: Involuntary smooth muscle External anal sphincter: Voluntary skeletal muscle
146
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
147
Vessels of the Large Intestine
First half: Superior mesenteric artery Distal half: Inferior mesenteric artery
148
Process of Digestion Diagram
149
Liver
Largest gland, vital for digestion, metabolism, and detoxification Produces bile to emulsify fats Performs metabolic functions Hepatocyte: Functional cells of the liver
150
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
151
Portal Triad
1. Bile duct: Carries bile to gallbladder or duodenum 2. Hepatic portal vein: Carries nutrient-rich blood from GI tract 3. Hepatic artery: Supplies oxygenated blood to liver
152
Gallbladder
Beneath liver, right upper quadrant ~7-10 cm long, holds 30-50 ml bile Concentrates and expels bile into duodenum for fat digestion
153
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
154
Pancreas
Dual function Endocrine: Produces insulin and glucagon to regulate blood sugar Exocrine: Acinar cells secrete digestive enzymes
155
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
156
Key Pancreas Structures
Main pancreatic duct: Joins bile duct to form hepatopancreatic ampulla, empties into duodenum Arterial supply: Hepatic, splenic, and superior mesenteric arteries
157
Digestive System Diagram
158
Gastroesophageal Reflux Disease (GERD)
Weak lower esophageal sphincter - Stomach acid flows back into esophagus Heartburn, irritation
159
Peptic Ulcers
Mucosal erosion in alimentary canal Gastric ulcers: Pyloric region Duodenal ulcers: Duodenum region Caused by Helicobacter pylori and long-term NSAID use
160
Disorders of the Bowel
Inflammatory bowel disease - Inflammation of intestinal wall, autoimmune - Abdominal pain and diarrhea Crohn's disease Ulcerative colitis
161
Constipation
Infrequent stool, affects the large intestine Low fiber and dehydration Discomfort, potential complications
162
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)
163
Gallstones
Bile component imbalance Sudden intense right upper quadrant pain, nausea, vomiting, fever, jaundice
164
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