Digestive System Flashcards
(33 cards)
A complex network of organs and structures that work together to process the food we eat.
It’s primary function
Digestive System
Provide the body with the essential nutrients required for growth, energy, and overall health.
Key Processes of the Digestive System
- Digestion
- Absorption
Long tube that stretches from the mouth to the anus.
Major Components of the Digestive System
Alimentary Canal (Gastrointestinal Tract)
It consists of several distinct organs, each with specific roles in digestion.
Organs that assist in digestion but are not part of the alimentary can
Major Components of the Digestive System
Include organs like?
Accessory Digestive Organs:
- teeth
- salivary glands
- liver
- gallbladder
- pancreas
Secretes mucus, digestive enzymes, and hormones.
It also absorbs the nutrients from digested food into the bloodstream and offers protection against infectious diseases.
The Alimentary Canal
Structure?
Mucosa
- Surface Epithelium
- Lamina Propria
- Muscle Layer
Contains blood vessels that absorb and transport nutrients. The elastic fibers help maintain the shape of the organs.
The Alimentary Canal
Structure?
Submucosa
The submucosa is made of areolar and dense irregular connective tissue, which houses blood vessels, lymphatic vessels, and nerve fibers (submucosal nerve plexus).
Acts as a protective outer layer and reduces friction between organs.
The Alimentary Canal
Structure?
Serosa
Composed of the visceral peritoneum, a thin layer of fluid producing cells that cover the digestive organs.
This muscle layer regulates food movement through peristalsis (wave-like contractions) and segmentation (mixing of food).
The Alimentary Canal
Structure?
Muscularis Externa
- Circular Layer
- Longitudinal Layer
Where food is initially ingested and digestion begins. It is responsible for mechanical digestion (chewing) and chemical digestion (via saliva).
Organs of the Alimentary Canal
Structure
Mouth (Oral Cavity)
Shared passageway for both food and air. It initiates the swallowing process that moves food toward the esophagus.
Structure
Pharynx
- Nasopharynx: Located behind the nasal cavity.
- Oropharynx: Extends from the soft palate to the epiglottis.
- Laryngopharynx: Extends from the epiglottis to the base of the larynx.
Transports food from the mouth to the stomach via peristalsis.
Structure
Esophagus
A muscular tube, about 10 inches long,
that passes food through the diaphragm to the
stomach.
Its upper part contains skeletal muscle, while
the lower part contains smooth muscle.
A muscle at the junction between the esophagus and stomach that controls food passage into the stomach.
Cardioesophageal Sphincter
- Temporarily stores food and initiates protein digestion.
- It also mechanically churns food into a semi-liquid mixture called chyme.
Structure?
Stomach
- Cardiol region (entry point),
- Fundus
- Body
- Pylorus (exit point to the small intestine).
- Curvatures
- Omentum
The primary site for nutrient absorption.
Components
Small Intestine
- Duodenum: The first part of the small intestine where bile and pancreatic juices are mixed with chyme for digestion.
- Jejunum: The middle section, where the majority of nutrient absorption occurs.
- Ileum: The final portion of the small intestine, where nutrients are absorbed, and the remaining material is prepared for transfer to the large intestine
Absorbs water and electrolytes, forming and storing feces.
Components
Large Intestine
- Cecum
- Appendix
- Colon (Ascending, Transverse, Descending, Sigmoid),
- Rectum
- Anus
Small, pocket-like sacs formed by the contraction of muscle bands.
Functions
Haustra
- Absorbs water and electrolytes from the undigested food.
- Hosts beneficial bacteria that help synthesize vitamins B and K.
- Eliminates waste as feces
Help propel food downward into the esophagus.
The pharyngeal muscles (longitudinal and circular constrictor muscles)
These structures help protect the opening and keep food between the teeth
Lips and Cheeks
The roof of the mouth, composed of the hard (Anterior) and soft (Posterior) palates.
Palate
A fingerlike projection of the soft palate that helps prevent food from entering the nasal cavity.
Uvula
A muscle that aids in mixing food with saliva and initiating swallowing.
Tongue
Lymphoid tissue in the mouth and tongue that plays a role in immune defense.
Tonsils
Produce saliva containing amylase, an enzyme that begins carbohydrate digestiodigestion
Salivary Glands
The Digestive Process
- Mouth: Food is chewed and mixed with saliva, forming a bolus.
- Esophagus: The bolus is transported to the stomach via peristalsis.
- Stomach: Gastric juices begin digesting proteins, creating chyme.
- Small Intestine: Chyme mixes with bile and pancreatic enzymes, and nutrients are absorbed.
- Large Intestine: Water is absorbed, and waste is compacted
- Rectum and Anus: Waste is expelled as feces.
