DIGESTIVE SYSTEM Flashcards
GI provides the body with a continual supply of water, electrolytes, vitamins, and nutrients, which requires the following:
- Movement
- Secretion
- Absorption
- Circulation
- Control
Adaptation of Parts:
______: Facilitates simple passage of food.
Esophagus
Adaptation of Parts:
______: Acts as temporary storage for food.
Stomach
Adaptation of Parts:
______: Specialized for digestion and absorption.
Small Intestine
Physiologic Anatomy of the Gastrointestinal Wall
- Cross Section of the Intestinal Wall (from outer surface inward):
- Serosa
- Longitudinal Smooth Muscle Layer
- Circular Smooth Muscle Layer
- Submucosa
- Mucosa
______: Sparse bundles of smooth muscle fibers located in the deeper layers of the mucosa.
Mucosal Muscle
______: Executed by the various smooth muscle layers.
Motor Functions of the gut
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A ______
SYNCYTIUM
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Length: ______-______ µm
200, 500
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Diameter: ______-______ µm
2, 10
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
______ connections enable coordinated activity
Inter-layer
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Made up of bundles of ______ fibers (______ and ______ layers)
parallel, longitudinal, circular
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Fibers are ______ connected (via ______)
electrically, gap junctions
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Functions as a single unit (______)
syncytium
GASTROINTESTINAL SMOOTH MUSCLE FUNCTIONS AS A SYNCYTIUM
Allows synchronized ______ and ______ for digestion
contractions, relaxations
______: Continuous slow electrical activity along muscle membranes
Intrinsic Electrical Activity
TYPES OF ELECTRICAL WAVES:
- Slow Waves
- Spike Potentials
- Changes in Voltage of the Resting Membrane Potential
- Entry of Calcium Ions Causes Smooth Muscle Contraction
- Tonic Contraction of Some Gastrointestinal Smooth Muscle
TYPES OF ELECTRICAL WAVES:
______:
- Gradual changes in resting membrane potential (______-______ mV)
Slow Waves, 5, 15
TYPES OF ELECTRICAL WAVES:
______:
- Frequency varies by region:
Stomach: ~______/min
Duodenum: ~______/min
Terminal Ileum: ~______-______/min
Slow Waves, 3, 12, 8, 9
TYPES OF ELECTRICAL WAVES:
______:
- Caused by interactions between smooth muscle cells and pacemaker cells (Interstitial cells of ______)
Slow Waves, Cajal
TYPES OF ELECTRICAL WAVES:
______:
- Typically don’t cause contraction directly
Slow Waves
TYPES OF ELECTRICAL WAVES:
______:
- True action potentials exceeding -40 mV
Spike Potentials
TYPES OF ELECTRICAL WAVES:
______:
- Frequency: ______-______ spikes/second, lasting ______-______ milliseconds
Spike Potentials, 1, 10, 10, 20
TYPES OF ELECTRICAL WAVES:
______:
- ______ slow wave peaks = ______ spike potential frequency
Spike Potentials, Higher, increased
TYPES OF ELECTRICAL WAVES:
______:
- Generated by calcium-sodium channels
Spike Potentials
TYPES OF ELECTRICAL WAVES:
______:
- Calcium influx initiates muscle ______
Spike Potentials, contractions
TYPES OF ELECTRICAL WAVES:
______:
- The resting membrane potential of a muscle cell is typically around ______ millivolts. Changes in this voltage can affect how easily the muscle can be ______.
Changes in Voltage of the Resting Membrane Potential, -56, excited
TYPES OF ELECTRICAL WAVES:
______:
- Depolarization makes muscles ______ excitable, while hyperpolarization makes them ______ excitable.
Changes in Voltage of the Resting Membrane Potential, more, less
TYPES OF ELECTRICAL WAVES:
______:
- ______ occurs when calcium ions enter muscle fibers.
Entry of Calcium Ions Causes Smooth Muscle Contraction, Contraction
TYPES OF ELECTRICAL WAVES:
______:
- Calcium activates ______ filaments through a ______ control mechanism, allowing contraction.
Entry of Calcium Ions Causes Smooth Muscle Contraction, myosin, calmodulin
Role of Slow and Spike Potentials
- Slow waves primarily allow ______ entry and do not directly cause muscle ______.
sodium, contraction
Role of Slow and Spike Potentials
- Significant ______ occurs during spike potentials, leading to ______.
calcium influx, contraction
TYPES OF ELECTRICAL WAVES:
______:
- Continuous contraction not linked to the ______ activity, lasting several ______ to ______.
Tonic Contraction of Some Gastrointestinal Smooth Muscle, rhythmic slow wave, minutes, hours
TYPES OF ELECTRICAL WAVES:
Tonic Contraction of Some Gastrointestinal Smooth Muscle
- Causes of Tonic Contraction:
- Continuous repetitive spike potentials
- Hormonal stimulation
- Continuous calcium ion entry
TYPES OF ELECTRICAL WAVES:
Tonic Contraction of Some Gastrointestinal Smooth Muscle
- Causes of Tonic Contraction:
Continuous repetitive spike potentials: ______ frequency leads to ______ contraction.
Higher, greater
TYPES OF ELECTRICAL WAVES:
Tonic Contraction of Some Gastrointestinal Smooth Muscle
- Causes of Tonic Contraction:
Hormonal stimulation: Causes partial ______ without ______.
depolarization, action potentials
TYPES OF ELECTRICAL WAVES:
Tonic Contraction of Some Gastrointestinal Smooth Muscle
- Causes of Tonic Contraction:
Continuous calcium ion entry: Occurs independently of ______.
membrane potential changes
NEURAL CONTROL OF GASTROINTESTINAL FUNCTION— ______ SYSTEM
ENTERIC NERVOUS
The ______ is a complex network of over ______ million neurons embedded in the ______, extending from the ______ to the ______. It controls gastrointestinal ______ and ______.
enteric nervous system (ENS), 100, gastrointestinal tract, esophagus, anus, movements, secretions
Plexuses:
- Myenteric Plexus (Auerbach’s Plexus)
- Submucosal Plexus (Meissner’s Plexus)
Plexuses:
______ Plexus (______ Plexus):
- Located between the longitudinal and circular muscle layers.
Myenteric, Auerbach’s
Plexuses:
______ Plexus (______ Plexus):
- Primarily controls gastrointestinal motility.
Myenteric, Auerbach’s
Plexuses:
______ Plexus (______ Plexus):
- Extends along the gastrointestinal tract.
Myenteric, Auerbach’s
Plexuses:
Myenteric Plexus (Auerbach’s Plexus):
Controls:
- Increased ______.
- Enhanced ______.
- Increased ______ and ______.
- Contains both ______ and ______ neurons.
tone of the gut wall, rhythmic contractions, contraction frequency, speed of peristalsis, excitatory, inhibitory
Plexuses:
______ Plexus (______ Plexus):
- Found in the submucosa.
Submucosal, Meissner’s
Plexuses:
______ Plexus (______ Plexus):
- Mainly regulates gastrointestinal secretion and local blood flow
Submucosal, Meissner’s
Plexuses:
______ Plexus (______ Plexus):
- Focuses on local control within segments of the intestine.
Submucosal, Meissner’s
Plexuses:
______ Plexus (______ Plexus):
- Integrates sensory signals for regulating secretion, absorption, and local contractions.
Submucosal, Meissner’s
Plexuses:
______ Connections:
- ______ and ______ fibers connect to both plexuses, ______ or ______ gastrointestinal functions.
Extrinsic, Sympathetic, parasympathetic, enhancing, inhibiting
Plexuses:
______:
- Originate from the ______, relaying information to both plexuses and other nervous system components.
Sensory Nerve Endings, gastrointestinal epithelium
Types of Neurotransmitters Secreted by Enteric Neurons
Over ______ neurotransmitters identified, including:
- ______
- ______
25, Excitatory, Inhibitory
Types of Neurotransmitters Secreted by Enteric Neurons
Over 25 neurotransmitters identified, including:
- Excitatory: ______, certain ______.
Acetylcholine, peptides
Types of Neurotransmitters Secreted by Enteric Neurons
Over 25 neurotransmitters identified, including:
- Inhibitory: ______, ______, vasoactive intestinal ______
Norepinephrine, epinephrine, polypeptide
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation:
- Divided into ______ (______ nerve) and ______ divisions.
Parasympathetic, cranial, vagus, sacral
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation:
- ______ enteric nervous system activity, ______ gastrointestinal functions.
Parasympathetic, Increases, enhancing
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation Usually Inhibits Gastrointestinal tract Activity
Sympathetic
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation:
- Originates from the spinal cord (______ to ______).
Sympathetic, T5, L2
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation:
- Generally inhibits gastrointestinal activity through ______ release.
Sympathetic, norepinephrine
AUTONOMIC CONTROL OF THE GASTROINTESTINAL TRACT
______ Stimulation:
- Can block peristalsis if strongly stimulated.
Sympathetic
Afferent Sensory Nerve Fibers From the Gut
Sources of Stimulation:
- ______, ______, and ______.
Gut mucosa irritation, excessive distention, specific chemicals
Afferent Sensory Nerve Fibers From the Gut
Sensory Pathways:
- ______ fibers transmit signals to the ______ and ______, influencing ______ and ______ control.
Afferent, spinal cord, brain stem, reflexes, gastrointestinal
Gastrointestinal Reflexes:
- Local Reflexes
- Long-Distance Reflexes
- CNS-Connected Reflexes
Gastrointestinal Reflexes:
______: Integrated within the ENS, controlling secretion and motility.
Local Reflexes
Gastrointestinal Reflexes:
______: From gut to prevertebral ganglia and back, such as the gastrocolic reflex.
Long-Distance Reflexes
Gastrointestinal Reflexes:
______: Involving the spinal cord or brain stem, including gastric control and defecation reflexes.
CNS-Connected Reflexes
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
- Gastrointestinal hormones play crucial roles in regulating ______ processes, including ______ and ______. They are released into the ______ circulation and act on specific target cells, even when nervous connections are severed.
digestive, secretion, motility, portal
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
- Gastrin
- Cholecystokinin (CCK)
- Secretin
- Glucose-dependent Insulinotropic Peptide (GIP)
- Motilin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
- Secreted by “G” cells in the ______ of the ______.
Gastrin, antrum, stomach
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Stomach distention.
Gastrin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Presence of protein products.
Gastrin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Gastrin-releasing peptide from gastric mucosa nerves (______ stimulation).
Gastrin, vagal
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Stimulates gastric acid secretion.
Gastrin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Promotes growth of gastric mucosa.
Gastrin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
- Secreted by “I” cells in the ______ of the ______ and ______.
Cholecystokinin (CCK), mucosa, duodenum, jejunum
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Digestive products of fat (fatty acids and monoglycerides).
Cholecystokinin (CCK)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Contracts the gallbladder, releasing bile into the small intestine.
Cholecystokinin (CCK)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Inhibits gastric motility, slowing stomach emptying.
Cholecystokinin (CCK)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Suppresses appetite by signaling the brain through sensory afferent fibers.
Cholecystokinin (CCK)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
- Secreted by “S” cells in the ______ of the ______.
Secretin, mucosa, duodenum
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Acidic gastric juice entering the duodenum.
Secretin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Promotes pancreatic secretion of bicarbonate to neutralize acid.
Secretin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Has a mild effect on gastrointestinal motility.
Secretin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
- Secreted by the mucosa of the upper small intestine.
Glucose-dependent Insulinotropic Peptide (GIP)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Fatty acids, amino acids, and to a lesser extent, carbohydrates.
Glucose-dependent Insulinotropic Peptide (GIP)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Decreases gastric motility, slowing emptying into the duodenum.
Glucose-dependent Insulinotropic Peptide (GIP)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Stimulates insulin secretion at lower blood levels.
Glucose-dependent Insulinotropic Peptide (GIP)
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
- Secreted by the stomach and upper duodenum during fasting.
Motilin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Stimuli for Secretion:
- Occurs cyclically every 90 minutes during fasting.
Motilin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Increases gastrointestinal motility.
Motilin
HORMONAL CONTROL OF GASTROINTESTINAL MOTILITY
Hormones:
______
Actions:
- Stimulates interdigestive myoelectric complexes that move through the stomach and small intestine.
Motilin
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
- The gastrointestinal tract exhibits two main types of movements essential for digestion and absorption: ______ movements and ______ movements.
propulsive, mixing
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Propulsive Movements:
______
- Is the primary propulsive movement in the gastrointestinal tract. It’s a coordinated contraction that pushes food forward, similar to squeezing a tube.
Peristalsis
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Propulsive Movements:
Peristalsis
- Stimuli: Peristalsis is triggered by the distention of the ______, ______ or ______ irritation, and strong ______ signals.
gut, chemical, physical, parasympathetic
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Propulsive Movements:
Peristalsis
- Role of the Myenteric Plexus: The myenteric plexus is essential for ______ peristalsis.
effective
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Propulsive Movements:
Peristalsis
- Direction: Peristalsis generally moves food towards the ______, following the “______.”
anus, law of the gut
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Mixing Movement:
______
- Are responsible for mixing intestinal contents. Unlike peristalsis, which moves food forward, these
contractions create intermittent constrictions along the gut wall, chopping and mixing the contents.
Segmentation Contractions
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Mixing Movement:
Segmentation Contractions
- Mixing vs. Propulsion: In some areas, ______ contractions can also assist in mixing, especially when a ______ blocks forward movement.
peristaltic, sphincter
FUNCTIONAL MOVEMENTS IN THE GASTROINTESTINAL TRACT
Mixing Movement:
Segmentation Contractions
- Variability: The specific mixing movements can ______ throughout the gastrointestinal tract, adapting to the needs of each segment.
differ
GASTROINTESTINAL BLOOD FLOW— SPLANCHNIC CIRCULATION
- The splanchnic circulation supplies blood to the ______, ______, ______, and ______. A unique feature of this system is that all blood from these organs flows through the ______ via the ______ before entering general circulation. This allows the liver to filter and process substances absorbed from the gut.
gastrointestinal tract, spleen, pancreas, liver, liver, portal vein
Blood Flow through the Liver
Filtration: As blood passes through the liver ______, ______ cells remove bacteria and other harmful particles.
sinusoids, reticuloendothelial
Blood Flow through the Liver
Nutrient Processing: The liver processes ______, ______ nutrients absorbed from the gut, ______ a portion and ______ the rest.
non-fat, water-soluble, storing, metabolizing
Blood Flow through the Liver
Fat Absorption: Fats are initially absorbed into the ______ system and enter ______ through the ______, bypassing the ______.
lymphatic, systemic circulation, thoracic duct, liver
ANATOMY OF THE GASTROINTESTINAL BLOOD SUPPLY
Arterial Supply: The gastrointestinal tract is supplied by major arteries including the ______ and ______, with smaller arteries branching out to supply the walls of the ______ and ______.
superior mesenteric artery, inferior mesenteric artery, small, large intestines
ANATOMY OF THE GASTROINTESTINAL BLOOD SUPPLY
Vascular Organization: Arteries branch within the ______, forming a network that ensures adequate blood supply to the ______ and ______.
gut wall, muscle layers, intestinal villi
EFFECT OF GUT ACTIVITY AND METABOLIC FACTORS ON GASTROINTESTINAL BLOOD FLOW
______ Blood Flow: Blood flow in the gastrointestinal tract correlates directly with ______ levels. For example, during nutrient absorption, blood flow can increase up to ______. After meals, blood flow rises significantly but decreases over ______-______ hours back to resting levels.
Activity-Dependent, local activity, eightfold, 2, 4
MECHANISMS OF INCREASED BLOOD FLOW DURING GASTROINTESTINAL ACTIVITY:
- Vasodilator Substances
- Metabolic Demand
MECHANISMS OF INCREASED BLOOD FLOW DURING GASTROINTESTINAL ACTIVITY:
Vasodilator Substances:
- Hormones like ______, ______, ______, and ______ released from the ______ promote ______ during digestion.
cholecystokinin, vasoactive intestinal peptide, gastrin, secretin, intestinal mucosa, vasodilation
MECHANISMS OF INCREASED BLOOD FLOW DURING GASTROINTESTINAL ACTIVITY:
Vasodilator Substances:
- ______ (______ and ______) released from ______ also contribute to increased blood flow.
Kinins, kallidin, bradykinin, glands
MECHANISMS OF INCREASED BLOOD FLOW DURING GASTROINTESTINAL ACTIVITY:
Metabolic Demand:
- ______ oxygen levels in the gut wall during active digestion lead to ______ blood flow, aided by the accumulation of ______ like ______.
Decreased, increased, vasodilators, adenosine
“______” BLOOD FLOW IN VILLIS
Vascular Arrangement: In the intestinal villi, ______ and ______ run ______ but in ______ directions, allowing significant oxygen to diffuse from the ______ blood to the ______ blood before reaching the tips of the villi. This “______” mechanism can lead to ______, especially in conditions like ______, resulting in potential ______ damage to the villi.
COUNTERCURRENT, arterioles, venules, parallel, opposite, arterial, venous, countercurrent, oxygen deficits, circulatory shock, ischemic
NERVOUS CONTROL OF GASTROINTESTINAL BLOOD FLOW
______: Increases blood flow and glandular secretion during digestion, primarily as a secondary effect of enhanced glandular activity.
Parasympathetic Stimulation
NERVOUS CONTROL OF GASTROINTESTINAL BLOOD FLOW
______: Causes vasoconstriction in the gastrointestinal tract, reducing blood flow. This is particularly useful during exercise or shock when blood needs to be redirected to vital organs like the heart and brain.
Sympathetic Stimulation
NERVOUS CONTROL OF GASTROINTESTINAL BLOOD FLOW
______: After initial sympathetic vasoconstriction, local metabolic mechanisms can override this effect, restoring blood flow to essential areas.
Autoregulatory Escape
PROPULSION AND MIXING OF FOOD IN THE ALIEMENTARY TRACT
Ingestion of Food
- Food intake is driven by ______, while the choice of food is influenced by ______. Both mechanisms are vital for nutritional health.
hunger, appetite
PROPULSION AND MIXING OF FOOD IN THE ALIEMENTARY TRACT
Mastication (Chewing)
- ______ play a central role in chewing, with ______ cutting food and ______ grinding it. Chewing is
largely controlled by the ______ and is often a ______ action. Chewing enhances digestion by breaking down food, especially tough fruits and vegetables, making it easier for digestive enzymes to act.
Teeth, incisors, molars, brainstem, reflex
Swallowing (______) is a complex process divided into three stages: ______, ______ (______), and ______ (______).
Deglutition, voluntary, pharyngeal, involuntary, esophageal, involuntary
Swallowing is a complex process divided into three stages: voluntary, pharyngeal (involuntary), and esophageal (involuntary). The pharyngeal stage involves closing the ______ to prevent food from entering the ______ tract, while the esophageal stage uses ______ to move food to the stomach.
trachea, respiratory, peristaltic waves
Esophageal Stage of Swallowing
Two types of peristalsis move food through the esophagus:
- ______ peristalsis (______) and
- ______ peristalsis (triggered by ______).
The lower ______ prevents stomach acid from flowing back into the esophagus.
primary, continuous movement, secondary, food retention, esophageal sphincter
Stomach Motor Functions
The stomach has three primary motor functions:
(1) storing food,
(2) mixing it with gastric secretions to form chyme, and
(3) gradually releasing chyme into the small intestine for further digestion and absorption
The stomach has two parts: the ______ (upper) and ______ (lower) portions. When food stretches the stomach, ______ reflex relaxes the stomach wall, allowing it to store up to ______ liters of food.
orad, caudad, vagovagal, 1.5
Stomach
______ mix the food, forming ______, which is gradually emptied into the ______.
Peristaltic waves, chyme, small intestine
Stomach
______ occur when the stomach is empty, the person sometimes felt ______ in the ______ of stomach called ______.
Hunger contractions, mild pain, pit, hunger pangs
Stomach
Emptying is regulated by the ______ and ______ reflexes.
pyloric pump, duodenum enterogastric
Stomach
Hormones like cholecystokinin (CCK) and gastrin play key roles in controlling ______.
stomach motility
MOVEMENT OF THE SMALL INTESTINE
The small intestine has two main types of movements: ______ and ______, both contributing to food digestion and movement.
mixing contractions, propulsive contractions
MOVEMENT OF THE SMALL INTESTINE
MIXING CONTRACTIONS (SEGMENTATION)
- Segmentation contractions occur when the intestine is stretched by ______, causing ______. These contractions divide the intestine into segments, promoting mixing of food with ______. Frequency is controlled by ______, with a maximum of ______ per minute in the duodenum and proximal jejunum and ______-______ per minute in the ileum. ______ reduces contraction strength by blocking the enteric nervous system.
chyme, localized contractions, intestinal secretions, electrical slow waves, 12, 8, 9, Atropine
MOVEMENT OF THE SMALL INTESTINE
PROPULSIVE MOVEMENTS
- Peristalsis propels chyme toward the ______ at ______–______ cm/sec, slower in the ______. Nervous and hormonal control increases ______ post-meal, driven by factors like ______ and ______. Peristalsis spreads chyme for ______ and may be blocked at the ______ until triggered by the ______ reflex. Peristaltic rush occurs during severe irritation, rapidly clearing the small intestine. Contractions of the ______ and ______ aid in absorption by increasing surface area and promoting lymph flow.
anus, 0.5, 2.0, terminal ileum, peristaltic activity, gastrin, CCK, absorption, ileocecal valve, gastroileal, muscularis mucosae, villi