DIGESTIVE SYSTEM Flashcards
T or F
The gastrointestinal (GI) tract or alimentary canal is a continuous tube that extends from the throat to the anus through the thoracic and abdominopelvic cavities
FLASE
The gastrointestinal (GI) tract or alimentary canal is a continuous tube that extends from the mouth to the anus through the thoracic and abdominopelvic cavities
Organs of the GI tract
Mouth,
pharynx,
esophagus,
stomach,
small intestine, and
large intestine
Accessory organs of the GI tract
Teeth,
tongue,
salivary glands,
liver,
gallbladder, and
pancreas
what is Ingestion?
o taking food and liquid into the mouth
Release of substances, water, acid, buffers, and enzymes into the lumen (interior space) of the GI tract
Secretion
T or F
In normal secretion,
- 3-7L of secretions
- Mixing and propulsion: propulsive or peristaltic movement along the GI tract
- Ability to mix and move material along its length is called motility
FALSE
5-7L of secretions
Mixing and propulsion: propulsive or peristaltic movement along the GI tract
Ability to mix and move material along its length is called motility
Mechanical and chemical breakdown or digestion of food
Digestion
Passage of digested products from the GI tract into the blood and lymph
Absorption
Elimination through feces and urine along the GI tract
Defecation
LAYERS OF THE GI TRACT WALL
- Serosa
- Muscularis Externa (or Muscularis)
- Submucosa
- Mucosa
Epithelium - Lamina propria - Muscularis mucosae:
o “Brain of the gut”; special nervous system for the GI tract
Enteric Nervous System
T or F
Sympathetic function: inhibitory effect, which may be caused by anxiety, anger, or fear; has a connection with myenteric and meissner plexus
Parasympathetic function: excitatory effect; has a connection with vagus and pelvic nerves
TRUE
The Enteric Nervous System is composed of how many neurons?
o Consists of about 100 million neurons extending from the esophagus to the anus
What are the CONTROL OF GI TRACT FUNCTION
Neural Regulation?
A. Autonomic Nervous System
B. Enteric Nervous System
What are the Control of the GI tract function Hormonal Regulation
A. GI Tract Hormones
B. Paracrines
Neurocrines
o It is the largest serous membrane of the body
PERITONEUM
The PERITONEUM is divided into 2 parts. What are they?
a) Parietal peritoneum: lines the abdominal cavity wall
b) Visceral peritoneum: cover organs in the cavity
o Largest peritoneal fold, which drapes over the transverse colon and coils of the small intestine like a “fatty apron”
Greater Omentum
Attaches the liver to the anterior abdominal wall and diaphragm
Connects the right and left lobes of the liver (the liver has 4 lobes: right, left, caudate, & quadrate lobes)
Falciform Ligament
Suspends the stomach and duodenum from the liver
Pathway for blood vessels entering the liver and contains the hepatic vein and artery
Binds the jejunum and ileum of the small intestine to the posterior abdominal wall
Lesser Omentum
o Binds the transverse (transverse mesocolon) and sigmoid (sigmoid mesocolon) colon of the large intestine to the posterior abdominal wall
Mesocolon
o Also known as oral or buccal cavity and is formed by the cheeks, hard and soft palates, and tongue
MOUTH
o Composition of saliva:
a. Mucin: makes saliva a good lubricant
b. Lysozyme, IgA: for protection
c. Salivary amylase (ptyalin)
o Function of saliva:
Initial digestion of carbohydrates
Lubrication, swallowing, taste bud stimulation
Protection of the oral cavity
o Types of immunoglobulins
IgG, IgA, IgM, IgE, IgD (GAMED)
T or F
Water is secreted by labial, buccal, palatal, parotid, submandibular, and lingual (sublingual gland) glands
FALSE
Saliva is secreted by labial, buccal, palatal, parotid, submandibular, and lingual (sublingual gland) glands
An accessory digestive organ composed of skeletal muscle covered mucous membrane
Forms the floor of the oral cavity
Tongue
o Maneuvers food for chewing, shaped food into a bolus, and forces the food to the back of the mouth for swallowing
Tongue
o The extrinsic muscles of the tongue are:
Hyoglossus
Genioglossi
Myeloglossu
Styloglossus
o 4 types of papillae (increases surface area):
- Vallate
- Foliate
- Fungiform
- Filiform
The Teeth is also known as?
And is used for?
Also known as dentes, which are used for grinding food into smaller sizes
T or F
Humans have two sets of teeth during a lifetime:
TRUE
A total of 20 teeth by age 2; first teeth to appear are the lower central incisors at about 6 months
- Deciduous teeth (baby or milk teeth):
- replace deciduous teeth between the ages 6 and 12; a total of 32 teeth but sometimes wisdom teeth never erupt or are absent
- Permanent teeth:
T or F
- Wisdom teeth usually appears between ages of 7 to 25
FALSE
- Wisdom teeth usually appears between ages of 17 to 25
funnel shaped tube that extends from the internal nares to the esophagus posteriorly and to the larynx anteriorly
Pharynx
about 25 cm long; posterior to the trachea, connects the pharynx with the stomach; pierces the diaphragm through an opening called the esophagus hiatus
Esophagus
T or F
o Takes 24 seconds for solids to reach stomach 1-3 sec for liquids
FALSE
o Takes 8 seconds for solids to reach stomach 1-3 sec for liquids
PARTS OF ESOPHAGUS
cervical, thoracic, and abdominal esophagus
T or F
The esophagus has two sphincters: medial and lateral esophageal sphincters
FALSE
Has two sphincters: upper and lower esophageal sphincters
o J or inverted C-shaped organ inferior to the diaphragm and the most dilatable structure of the GI tract
STOMACH
o A mixing chamber of bolus and gastric juices to form chime
STOMACH
o Reservoir of food before release into the small intestine
STOMACH
T or F
The stomach can
o Secretes hormone and other substances
o Can store up to 1 gallon or 3-7L
True
Regions of the Stomach
a. Cardia
b. Fundus
d. Body
d. Antrum
e. Pylorus
Gland Cells in the Gastric Glands
Mucous neck cells:
Parietal cells
Chief cells
G cells
What does G cells do?
G cells: secrete gastrin into the bloodstream
What does Chief cells: do?
Chief cells: secrete pepsinogen and gastric lipase
T or F
Parietal cells: produce intrinsic factor (needed for absorption of vitamin B12) and hydrochloric acid
If there is an insufficient intrinsic factor, pernicious pneumonia may occur
FALSE
Parietal cells: produce intrinsic factor (needed for absorption of vitamin B12) and hydrochloric acid
If there is insufficient intrinsic factor, pernicious anemia may occur
