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Flashcards in Digestive Part I Deck (153)
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1
Q

What are the 6 Basic Processes for Digestion?

A
  1. Ingestion
  2. Secretion
  3. Mixing & Propulsion
  4. Digestion
  5. Absorption
  6. Defecation
2
Q

Digestion begins where & with what two mechanisms?

A

In the MOUTH

via Mechanical & Chemical Digestion

3
Q

Mechanical Digestion is accomplished by & creates what?

A

Mastication

  • Food is reduced to a “BOLUS” (easily swallowed mass)
  • Saliva begins to dissolve food
4
Q

Chemical Digestion is accomplished by?

A

Enzymes secreted in the mouth

5
Q

Name the enzymes secreted in the mouth.

A

Salivary Amylase

Lingual Lipase

6
Q

Characteristics of Salivary Amylase.

A
  • Initiates breakdown of carbohydrates
  • Chloride ion: activated in the mouth in saliva
  • Stomach acid deactivates
7
Q

Characteristics of Lingual Lipase.

A
  • Initiates breakdown of lipids (TAGs)

- Activated in the stomach via stomach acid

8
Q

From the mouth food passes into what when swallowed?

A

Pharynx

9
Q

Characteristics of Pharynx.

A
  • Funnel-shaped tube
  • Extends from internal nares to esophagus
  • Composed of skeletal muscle
  • Lined with mucous membrane
10
Q

What are the three parts of the Pharynx?

A

Nasopharynx
Oropharynx
Hypo/Laryngopharynx

11
Q

What part/s of the Pharynx functions in only Respiration?

A

Nasopharynx

12
Q

What part/s of the Pharynx function in digestion & respiration?

A

Oropharynx

Hypo/Laryngopharynx

13
Q

What specific parts of the pharynx does food pass through when swallowed?

A

Oropharynx (1st)

Laryngopharynx (2nd)

14
Q

Characteristics of the Esophagus.

A
  • Collapsible muscular tube
  • Usually 10” long
  • Lies posterior to the trachea
15
Q

Esophagus begins where, passes through what structures, & ends where?

A

Begins: Inferior end of hypo/laryngopharynx
Passes: Through inferior portion of neck, enters mediastinum, & pierces the diaphragm
Ends: Superior portion of stomach

16
Q

What is the name of the area the esophagus pierces the diaphragm?

A

Esophageal Hiatus

17
Q

What is a hiatal hernia?

A

Portion of the stomach that herniates through the esophageal hiatus

18
Q

Name the layers (histology) of the Esophagus. (Superficial to lumen)

A
  1. Adventitia
  2. Muscularis
  3. Submucosa
  4. Mucosa (3 layers)
19
Q

What role does the Adventitia layer of the Esophagus play?

A

Attaches esophagus to surrounding structures

20
Q

Describe the Muscularis layer.

A

Superior 1/3 esophagus is skeletal muscle
Middle 1/3 esophagus is skeletal transitioning to smooth muscle
Inferior 1/3 esophagus is smooth muscle

21
Q

What is contained in the Submucosa Layer of the Esophagus?

A

Areolar connective tissue
Blood Vessels
Mucous Glands

22
Q

What are the 3 layers of the Mucosa layer of the Esophagus?

A
Muscularis mucosae (smooth muscle)
Lamina propria (areolar connective tissue)
Nonkeratinized stratified squamous epithelium
23
Q

What benefit is derived from having Nonkeratinized stratified squamous epithelium lining the lumen of the Esophagus?

A

Considerable protection against abrasion from food particles

24
Q

What occurs at each end of the esophagus involving the Muscularis layer?

A

Muscularis layer thickens forming a sphincters

25
Q

What is the name and function of the most superior sphincter of the Esophagus?

A

Upper Esophageal Sphincter (UES):

  • Skeletal Muscle
  • Regulates movement of food from hypopharynx to esophagus
26
Q

What is the name & function of the inferior sphincter of the Esophagus?

A

Lower Esophageal Sphincter (LES):

  • Smooth Muscle
  • Regulates movement of food from esophagus to stomach
27
Q

Name the different aspects of the physiology of the Esophagus.

A
  • Secretes Mucous (Protective Function)
  • Transports food to the stomach
  • Does NOT produce Digestive Enzymes
  • Does NOT participate in Absorption
28
Q

What is Deglutition?

A

The Act of Swallowing

(Movement of food from the mouth into the stomach)

29
Q

What is involved in the process of Deglutition?

A

Facilitated by secretion of saliva & mucous

Involves: Mouth, Pharynx, Esophagus

30
Q

What are the Stages of Deglutition?

A
  1. Voluntary Stage
  2. Pharyngeal Stage
  3. Esophageal Stage
31
Q

What is occurring during the voluntary stage of deglutition?

A
  • Swallowing starts when bolus is forced to back of oral cavity
  • Bolus travels backward toward the oropharynx by the movement of the tongue upward & backward against the palate
32
Q

What is occurring during the Pharyngeal Stage of deglutition?

A
  • Bolus moves into oropharynx then through hypo/laryngopharynx & into esophagus
  • Bolus stimulates receptors which send impulses to deglutition center in medulla & lower pons
  • Nerve impulses cause soft palate & uvula to move upward to close off nasopharynx
  • Impulses cause epiglottis to close off larynx
  • Bolus moves through oropharynx & hypo/laryngopharynx
33
Q

What is occurring during the Esophageal Stage of deglutition?

A
  • Begins once bolus enters esophagus

- Peristalsis pushes bolus onward to stomach

34
Q

How long does it take for solid or semisolid food to travel from mouth to stomach?

A

4-8 Seconds

35
Q

How long does it take liquids to travel from mouth to stomach?

A

1 Second

36
Q

What are the layers of the GI Tract from lower esophagus to anal canal?

A

Serosa or Adventitia
Muscularis
Submucosa
Mucosa

37
Q

The Serosa Layer is found on all parts of the GI except where?

A

Esophagus

Proximal Portion of Duodenum (closest to stomach)

38
Q

What is the Serosa layer composed of?

A

-Areolar connective tissue & simple squamous epithelium (Mesothelium)

39
Q

What is another name in which the Serosa Layer?

A

Visceral Peritoneum

40
Q

What is the Adventitia layer composed of?

A

Single layer of connective tissue for esophagus & proximal duodenum

41
Q

What is significant of the Muscularis Layer?

A

Skeletal Muscle: Voluntary

Smooth Muscle: Involuntary

42
Q

Where is the voluntary skeletal muscle found?

A

Mouth, pharynx, superior aspect of esophagus

External anal sphincter

43
Q

What is significant of the involuntary smooth muscle layer?

A
  • Contains Myenteric Plexus (Plexus of Auerbach)
  • Contraction help mix & propel food forward break it down
  • Two layers: Inner circular, outer longitudinal
44
Q

What is the Myenteric Plexus (Plexus of Auerback)?

A

Network of neurons between the circular & Longitudinal muscle layers

45
Q

What does the submucosa layer consist of?

A
  • Areolar connective tissue (binds mucosa to Muscularis)
  • Blood & Lymph Vessels that receive absorbed food moleules
  • Contains Submucosal Plexus (Plexus of Meissner)
46
Q

How many layers is the Mucosa Layer of the GI Tract consist of?

A

3 Layers

47
Q

Name the layers of the Mucosa Layer of the GI Tract from outer to inner?

A
  • Muscularis Mucosae
  • Lamina Propria
  • Epithelium
48
Q

What are the characteristics of the Muscularis Mucosae?

A
  • Thin Layer smooth muscle fibers
  • Causes the mucous membrane of small intestine & stomach to have the folded appearance
  • Folds increase surface area for digestion & absorption
  • Movement ensures all absorptive cells are fully exposed to contents
49
Q

What are the characteristics of the Lamina Propria?

A
  • Areolar connective tissue containing blood & lymphatic vessels (allow nutrients to reach tissues)
  • Supports epithelium & binds to Muscularis mucosae
  • CONTAINS majority of MALT
50
Q

What does MALT stand for?

A

Mucosa-associated Lymphatic Tissue

51
Q

What is MALT?

A

-Lymphatic nodular tissue contains immune cells that protect against disease

52
Q

Where is MALT especially present?

A

Tonsils
Small Intestine
Appendix
Large Intestine

53
Q

What are the characteristics of the Mucosa Layer?

A
  • Nonkeratinized stratified squamous cells
  • Simple Columnar cells
  • Exocrine Cells
  • Enteroendocrine Cells
54
Q

Where is the Nonkeratinized stratified squamous cells found & what is it’s function?

A
Mouth
Pharynx
Esophagus
Anal Canal
-Protective Function
55
Q

Where is the Simple Columnar cells found & function?

A

Stomach
Intestines
-Secretion & Absorption
-Tight junctions between cells prevent leakage

56
Q

What is the function of the Exocrine Cells?

A

Secrete mucous & fluid into lumen

57
Q

What is the function of the Enteroendocrine cells?

A

Secrete hormones into lumen

58
Q

Name the Neural innervation of the GI Tract?

A
Intrinsic Nerves (Enteric nervous system)
Extrinsic Nerves (Autonomic Nervous System)
59
Q

What are the characteristics of the ENS?

A
  • “Brain” of the gut
  • 100,000,000 neurons esophagus to anus
  • Myenteric (Auerback) Plexus
  • Submucosal Plexus (Plexus of Meissner)
60
Q

Where is the Myenteric (Auerbach) Plexus located?

A

Between Longitudinal & Circular Smooth Muscle Layers of the Muscularis

61
Q

Where is the Submucosal Plexus (plexus of Meissner) located?

A

Submucosa

62
Q

What do each plexuses consist of?

A

Neurons, interneurouns, sensory neurons

63
Q

What supplies motor impulses to longitudinal & circular smooth muscle layers of Muscularis?

A

Myenteric (Auerback) Plexus

64
Q

The innervation from the Myenteric Plexus provides what?

A

-Majority of motility of GI tract

Frequency & strength of contraction of Muscularis

65
Q

What supplies motor neurons of the secretory cells of the mucosal epithelium?

A

Submucosal (Meissner) Plexus

66
Q

The innervation from Submucosal Plexus provides what?

A

Controlling of secretions of the organs of the GI tract

67
Q

What do the interneurons allow?

A

Connection of the myenteric & submucosal plexuses

68
Q

Where are the sensory neurons found?

A

Supply mucosal epithelium

69
Q

What are the functions of the Sensory Neurons?

A

Chemoreceptors

Baroreceptors

70
Q

What activates the Chemoreceptors?

A

Certain chemicals in food located in the lumen of GI organs

71
Q

What activates the Baroreceptors (Stretch Receptors)?

A

Food stretches distends the wall of GI organs

72
Q

What purpose does the ANS serve for the GI Tract?

A
  • Helps regulate ENS
  • Vagus Nerves (CN-X) supply parasympathetic fibers
  • Parasympathetic nerves for neural connections with ENS
73
Q

Where is the Vagus (CN-X) Nerve not apart of innervation of the GI?

A

Last half of the large intestine

74
Q

What innervates the last half of the large intestine?

A

Parasympathetic fibers supplied from sacral spinal cord

75
Q

Stimulation of the parasympathetic nerves cause?

A

Increase in GI secretion & motility by increasing activity of ENS

76
Q

The ANS Sympathetic nerves arise from where?

A

Thoracic & Upper Lumbar regions of spinal cord

connections with ENS

77
Q

What do the Sympathetic nerves cause?

A

Decrease GI secretion & motility by inhibiting the ENS neurons

78
Q

What do emotions such as fear “fight-or-flight”, anger, anxiety cause within the GI?

A

Sympathetic nerves slow digestion

79
Q

What is the largest serous membrane in the body?

A

Peritoneum

80
Q

What does the peritoneum consist of?

A
  • Layer of Simple Squamous Epithelium (Mesothelium)

- Underlying layer of Areolar Connective Tissue

81
Q

What is the peritoneum divided into?

A
  • Parietal Peritoneum: Lines wall of abdominopelvic cavity

- Visceral Peritoneum: Covers some organs in the cavity & is also considered their Serosa

82
Q

What is the space between the two layers that contains lubricating serous fluid?

A

Peritoneal Cavity

83
Q

What is Ascites?

A

Excess fluid accumulates in the peritoneal cavity

84
Q

What is the most common cause of Ascites?

A

Liver Failure

85
Q

What is the space behind the peritoneum called?

A

Retroperitoneal

86
Q

What organs lie in this space & are covered anteriorly by the peritoneum?

A
Kidneys
Ascending Colon
Descending Colon
Duodenum
Pancreas
87
Q

This contains large folds that weave between the viscera & bind organs together & abdominal cavity, it contains blood vessels, lymph vessels, & nerves?

A

Peritoneum

88
Q

What are the five major folds of the Peritoneum?

A
Grater Omentum
Faciform Ligament
Lesser Omentum
Mesentery
Mesocolon
89
Q

What are the characteristics of the Greater Omentum?

A

Largest Peritoneal fold

  • Drapes over transvers colon & small intestine
  • Double sheet folds back on itself (4 layers)
  • Attaches to portions of stomach & duodenum, anterior small intestines, transverse colon
  • Contains adipose tissue
  • Lymph nodes (macrophages & Ab producing cells)
90
Q

What are the characteristics of the Falciform Ligament?

A
  • Peritoneal fold attaches the liver to ventral surface of abdominal wall
  • Free border contains Ligamentum teres (round ligament; remnant of umbilical vein)
91
Q

What is the only digestive organ attached to anterior abdominal wall?

A

Liver

92
Q

What are the characteristics of the Lesser Omentum?

A
  • Anterior fold in serosa of the stomach & distal duodenum (suspends the stomach & distal duodenum from the liver)
  • Pathway for blood vessels entering Liver
  • Contains Portal Vein, Common hepatic artery, common bile duct & some lymph nodes
93
Q

What is the fan shape fold that binds the jejunum & ileum of small intestine to posterior peritoneal wall?

A

Mesentery

94
Q

This fold extends from posterior peritoneal wall, wraps around small intestine & returns to origin?

A

Mesentery

95
Q

This fold consist of two separate folds that bind portions of large intestine to posterior abdominal wall, carries blood & lymphatic vessels to intestines, holds small intestines loosely in place?

A

Mesocolon

96
Q

What do the two separate folds of the Mesocolon bind to?

A

First binds the transverse colon

Second binds the sigmoid colon

97
Q

What is acute inflammation of the peritoneum?

A

Peritonitis

98
Q

What are some causes of Peritonitis?

A

Contamination from infectious microbes (Surgical wound, perforation or rupture of abdominal organs/structures)

  • Rubbing together of inflamed peritoneal surfaces
  • Peritoneal dialysis
99
Q

The mouth is also known as?

A

Oral or Buccal Cavity

100
Q

What forms the Oral/ Buccal Cavity?

A

Cheeks
Hard & Soft Palates
Tongue

101
Q

What do the Cheeks consist of?

A
  • External by skin
  • Internal Mucous membrane (Nonkeratinized stratified squamous epithelium)
  • Buccinator muscles lie in between external/internal surfaces
102
Q

What are the characteristics of the lips?

A
  • Contain Orbicularis Oris Muscle
  • External Skin, Internal Mucous Membrane
  • Muscles keep food in the mouth
  • Assist in speech
103
Q

What is the Oral space completely bound by cheeks, lips, gums, & buccal side of teeth?

A

Oral Vestibule

104
Q

What is the space that extends from lingual side of teeth back to the fauces?

A

Oral Cavity Proper

105
Q

What forms the roof of the mouth & separates the oral cavity from nasal cavity & allows chewing & breathing at the same time?

A

Palate

106
Q

What are the two divisions of the Palate?

A

Hard Palate

Soft Palate

107
Q

Which palate is the anterior portion of the roof of the mouth, formed by palatine & maxillae bones, covered by mucous membrane?

A

Hard Palate

108
Q

Which palate is the posterior portion of the rood of the mouth & is arched shaped muscular partition between oropharynx & nasopharynx , covered with mucous membrane?

A

Soft Palate

109
Q

This structure hands from free border of soft palate, conical muscular process, drawn upward during swallowing?

A

Uvula

110
Q

The base of the uvula, what are the two muscular fold that run down the lateral sides of the soft palate?

A

Palatoglossal Arch

Palatopharyngeal Arch

111
Q

What is the anterior fold that extends to the side of the base of the tongue?

A

Platoglossal Arch

112
Q

What is the posterior fold that extends to the side of the pharynx?

A

Palatopharyngeal Arch

113
Q

What are the small masses of lymphatic tissue that produce Ab to fight infection?

A

Tonsils

114
Q

What are the names of the different tonsils?

A

Palatine Tonsils
Lingual Tonsil
Pharyngeal tonsils

115
Q

What is the location of the Palatine Tonsils?

A

Between the arches

-Most commonly infected & removed

116
Q

What is the location of the Lingual Tonsil?

A

Base of the tongue

117
Q

What is the location of the Pharyngeal Tonsils?

A

Superior Portion of nasopharynx

118
Q

What is the other name of the Pharyngeal Tonsils?

A

Adenoids

119
Q

Which Tonsils are removed due to closing off of sinus drainage & cause difficulty breathing through the nose?

A

Pharyngeal Tonsils (Adenoids)

120
Q

Two types of Salivary Glands; What are the names of the Minor Glands in the lips, cheeks, palate, & tongue?

A

Labial
Buccal
Palatal
Lingual

121
Q

Two types of Salivary Glands; What are the names of the Major Glands (Secrete most of the saliva)?

A

Parotids
Submanibular
Sublingual

122
Q

What is the location of the Parotid Glands & how does it secrete saliva into the oral cavity?

A

Inferior & anterior to the ears between skin & masseter muscle
-Secretes via Parotid Duct (Stenson’s Duct)

123
Q

This duct pierces the buccinators muscle to open into oral vestibule opposite the second maxillary molar (upper)?

A

Parotid Duct (Stenson’s Duct)

124
Q

Where are the Submandibular Glands located & how do they secrete into the oral cavity?

A
  • Floor of the mouth, medial & partly inferior to the body of the mandible bone
  • Secretes: Submandibullar ducts (Wharton’s Ducts) open either side of lingual frenulum
125
Q

Where are the sublingual glands located and secrete via what ducts?

A

Beneath the tongue & superior to submandibular glands

-Lesser sublingual ducts, open into floor of the mouth in oral cavity proper

126
Q

What does Saliva consist of?

A

Chemically 99.5% water & 0.5% Solutes

127
Q

What are some of the solutes within Saliva?

A
Sodium
Potassium
Chloride
Bicarbonate
Phosphate
Dissolved gases, various organic substances, Immunoglobulin A, Lysozymes, Salivary amylase
128
Q

Which glands secrete serous liquid containing salivary amylase?

A

Parotid Glands

129
Q

Which glands secrete serous fluid & salivary amylase & contain mucous cells, a thicker version of what the Parotid glands secrete?

A

Submandibular Glands

130
Q

These glands secrete mostly mucous cells, it is thicker & only has a small amount of salivary amylase?

A

Sublingual Glands

131
Q

What role does water play in Saliva?

A

Allows for taste by gustatory receptors

Allows for digestive reactions to begin

132
Q

What do the Chloride ions do within Saliva?

A

Activate Salivary Amylase (breakdown of starches)

133
Q

What role does Bicarb & Phosphate ions play in digestion?

A

Buffer acidic foods

134
Q

What is the pH of Saliva?

A

6.35-6.85 (Slightly Acidic)

135
Q

What wastes are secreted through saliva?

A

Urea & Uric Acid

136
Q

What controls Salivation?

A

Autonomic Nervous System

137
Q

How much saliva is secreted daily on average?

A

1-1.5 liters

138
Q

Which portion of the Nervous System promotes continuous secretion of a moderate amount of saliva, which lubricates mucous membranes & esophagus & helps keep the movements of the tongue & lips moist during speech?

A

Parasympathetic

139
Q

Which portion of the Nervous System dominates Salivation during Stress?

A

Sympathetic

140
Q

What is Xerostomia?

A

Dry Mouth & Throat

141
Q

Impulses for taste are conveyed to two salivary nuclei in the brain stem called?

A

Superior Salivatory Nuclei

Inferior Salivatory Nuclei

142
Q

Which fibers return parasympathetic impulse to stimulate salivation?

A

Facial (CN-VII) Cranial Nerve

Glossopharyngeal (CN-IX) Cranial Nerve

143
Q

This accessory digestive organ is composed of skeletal muscle covered with a mucous membrane & its associated muscle form the floor of the oral cavity?

A

Tongue

144
Q

What does the tongue attach to?

A

Inferiorly: Hyoid Bone
Styloid process of temporal bone
Mandible

145
Q

What is the fold of mucous membrane in the midline of the ventral aspect of the tongue & attaches to the floor of the mouth, aids in limiting movement of tongue posteriorly?

A

Lingual Frenulum

146
Q

What is the clinical finding if this is abnormally short, rigid, or anteriorly placed; a person is said to be “tongue-tied” because of lack of movement of the tongue?

A

Ankyloglossia

147
Q

These glands are found in the lamina propria of the tongue & secrete watery serous fluid that contains lingual lipase?

A

Lingual Glands (Von Ebners Glands)

148
Q

What are characteristics of Lingual Lipase?

A

Acts on 30% of dietary triglycerides but is not activated until in the stomach

149
Q

What covers the Dorsal & lateral surfaces of the tongue?

A

Papillae

150
Q

These are nipple shaped projection of lamina propria covered with stratified squamous epithelium, many contain receptors for gustation & some for touch?

A

Papillae

151
Q

What are the different types of Papillae?

A

Vallate (Circumvallate)

Fungiform

152
Q

These papillae are approx. 12 form an inverted “V” shaped row at the back of the tongue & each one of the 12 contain 100-300 taste buds?

A

Vallate (Circumvallate) Papillae

153
Q

These papillae are mushroom shaped elevation scattered over the entire tongue surface and each contain about 5 taste buds?

A

Fungiform Papillae