Anatomy Review: DIgestive and Nervous Systems
The Digestive System
Module 22.1: Overview of the Digestive system
Alimentary Canal Accessory Organs
• Food passes directly through (tube) • Food does not usually come into direct
contact (*except teeth and tongue)
Oral cavity, pharynx, esophagus, stomach, Teeth, tongue, salivary glands, liver,
small intestine, large intestine gallbladder, pancreas
Basic Digestive Functions
- Fundamental function is to take food in the body and break it down into its
component nutrients to allow use by cells
- Critical role in fluid, electrolyte, and acid base homeostasis (intake and delivery
to blood)
- Ingesting vitamins and minerals, producing hormones, and excreting metabolic
wastes
Basic Digestive Processes
- Ingestion
- Secretion
- Propulsion
- Digestion (mechanical and chemical)
- Absorption
- Defecation
Organization of the abdominopelvic cavity
- Peritoneal membranes
- Peritoneal cavity
- Intra vs retroperitoneal
- Mesenteries
- Greater and lesser omentum
,Histology of the Alimentary Canal
Regulation of Motility
- Motility (movement) of alimentary canal is the key process
- Oral cavity, pharynx, superior portion of esophagus, and last portion of
large intestine -> skeletal muscle
- Rest of alimentary canal -> smooth muscle
- Motility takes several forms, such as swallowing, churning, peristalsis, and
defecation
- Neurological control -> autonomic nervous system (ANS) and enteric nervous
system (ENS)
- Endocrine system -> paracrine and hormones
Module 22.2 The Oral Cavity, Pharynx, and Esophagus
,Primary and Secondary Dentition
Oral Cavity
- Part of alimentary canal and holds teeth and tongue
- Salivary glands (some within and some nearby)
- Ingestion occurs
- Mechanical digestion -> mastication occurs with teeth, tongue, masseter and
temporalis muscles
- Assists chemical digestions by increasing surface area of food
- Chemical digestions begins
Tongue
- Lingual frenulum
- Filiform, fungiform, circumvallate & foliate papillae
- Sensory receptors = taste buds
- Extrinsic muscles control position of tongue
, - Intrinsic muscles control shape and size of tongue
Salivary Glands
- Acinar cell is basic secretory cell of salivary glands
- Serous cells - secrete water based fluid with enzymes and other solutes;
secretions are involved in digestive processes generally released just
before or during eating
- Mucous cells - secrete mucus; primarily involved in keeping the oral
mucosa moist; released continually
- Parotid glands have only serous cells
- Submandibular glands have mostly serous cells and small number of mucous
cells
- Sublingual glands contain mostly mucous cells
- Functions of saliva
- Moistening, lubricating, and cleansing oral mucosa
- Lysozyme and IgA deter growth of pathogenic bacteria in oral cavity
- Mechanical digestion, achieved by moistening and helping to mix ingested
food into bolus so it can be swallowed
- Chemical digestion, achieved by actions of salivary amylase
- Many food molecules dissolve in water of saliva and stimulate taste
receptors on tongue
Pharynx
- Oropharynx and laryngopharynx (nasopharynx isnt part of alimentary canal)
- Oropharynx houses 2 sets of tonsils
- Palatine tonsils
- Lingual tonsils
- Protect alimentary canal from pathogens that enter body via oral
and nasal cavities
The Digestive System
Module 22.1: Overview of the Digestive system
Alimentary Canal Accessory Organs
• Food passes directly through (tube) • Food does not usually come into direct
contact (*except teeth and tongue)
Oral cavity, pharynx, esophagus, stomach, Teeth, tongue, salivary glands, liver,
small intestine, large intestine gallbladder, pancreas
Basic Digestive Functions
- Fundamental function is to take food in the body and break it down into its
component nutrients to allow use by cells
- Critical role in fluid, electrolyte, and acid base homeostasis (intake and delivery
to blood)
- Ingesting vitamins and minerals, producing hormones, and excreting metabolic
wastes
Basic Digestive Processes
- Ingestion
- Secretion
- Propulsion
- Digestion (mechanical and chemical)
- Absorption
- Defecation
Organization of the abdominopelvic cavity
- Peritoneal membranes
- Peritoneal cavity
- Intra vs retroperitoneal
- Mesenteries
- Greater and lesser omentum
,Histology of the Alimentary Canal
Regulation of Motility
- Motility (movement) of alimentary canal is the key process
- Oral cavity, pharynx, superior portion of esophagus, and last portion of
large intestine -> skeletal muscle
- Rest of alimentary canal -> smooth muscle
- Motility takes several forms, such as swallowing, churning, peristalsis, and
defecation
- Neurological control -> autonomic nervous system (ANS) and enteric nervous
system (ENS)
- Endocrine system -> paracrine and hormones
Module 22.2 The Oral Cavity, Pharynx, and Esophagus
,Primary and Secondary Dentition
Oral Cavity
- Part of alimentary canal and holds teeth and tongue
- Salivary glands (some within and some nearby)
- Ingestion occurs
- Mechanical digestion -> mastication occurs with teeth, tongue, masseter and
temporalis muscles
- Assists chemical digestions by increasing surface area of food
- Chemical digestions begins
Tongue
- Lingual frenulum
- Filiform, fungiform, circumvallate & foliate papillae
- Sensory receptors = taste buds
- Extrinsic muscles control position of tongue
, - Intrinsic muscles control shape and size of tongue
Salivary Glands
- Acinar cell is basic secretory cell of salivary glands
- Serous cells - secrete water based fluid with enzymes and other solutes;
secretions are involved in digestive processes generally released just
before or during eating
- Mucous cells - secrete mucus; primarily involved in keeping the oral
mucosa moist; released continually
- Parotid glands have only serous cells
- Submandibular glands have mostly serous cells and small number of mucous
cells
- Sublingual glands contain mostly mucous cells
- Functions of saliva
- Moistening, lubricating, and cleansing oral mucosa
- Lysozyme and IgA deter growth of pathogenic bacteria in oral cavity
- Mechanical digestion, achieved by moistening and helping to mix ingested
food into bolus so it can be swallowed
- Chemical digestion, achieved by actions of salivary amylase
- Many food molecules dissolve in water of saliva and stimulate taste
receptors on tongue
Pharynx
- Oropharynx and laryngopharynx (nasopharynx isnt part of alimentary canal)
- Oropharynx houses 2 sets of tonsils
- Palatine tonsils
- Lingual tonsils
- Protect alimentary canal from pathogens that enter body via oral
and nasal cavities
