fisssiologi

Open Ended

Describe the role of gap junctions in the gastrointestinal smooth muscle function.

Fill in the Blank

Fill in the blank: The individual smooth muscle fibers in the gastrointestinal tract are arranged in bundles of as many as ___ parallel fibers.

Multiple Choice

What are the two types of electrical activity in the gastrointestinal smooth muscle?

• Slow waves

• Spikes

• Continuous waves

• Rhythmic waves

Open Ended

Explain the difference between slow waves and spike potentials in intestinal smooth muscle.

Fill in the Blank

Fill in the blank: The rhythm of contraction in the stomach is about ___ times per minute.

Multiple Choice

What is the frequency range of spike potentials in gastrointestinal muscle?

• 1 to 5 spikes per second

• 5 to 10 spikes per second

• 10 to 20 spikes per second

• 20 to 30 spikes per second

Multiple Choice

What are the interstitial cells of Cajal believed to act as in smooth muscle cells?

• Electrical pacemakers

• Chemical messengers

• Structural support

• Nerve fibers

Multiple Choice

What factors can depolarize the membrane of smooth muscle fibers?

• Stretching of the muscle

• Stimulation by acetylcholine

• Stimulation by parasympathetic nerves

• All of the above

Open Ended

Explain the concept of tonic contraction in gastrointestinal smooth muscle. How does it differ from rhythmic contractions?

Multiple Choice

What is the role of calcium ions in smooth muscle contraction in the gastrointestinal tract?

• They inhibit muscle contraction

• They cause muscle relaxation

• They activate myosin filaments

• They have no effect on muscle contraction

Multiple Choice

What types of neurotransmitters are secreted by enteric neurons as mentioned in the image?

• Acetylcholine

• Serotonin

• Dopamine

• All of the above

Fill in the Blank

Fill in the blank: The myenteric plexus consists mostly of a linear chain of many interconnecting neurons that extends the entire length of the gastrointestinal tract, and it is mainly concerned with controlling ___ activity along the length of the gut.

Multiple Choice

What are the differences between the myenteric and submucosal plexuses?

• Myenteric plexus is mainly concerned with controlling intestinal smooth muscle activity, while submucosal plexus controls local intestinal secretion.

• Myenteric plexus is located in the submucosa, while submucosal plexus is located in the muscularis layer.

• Both plexuses have the same functions and locations.

• Myenteric plexus is primarily excitatory, while submucosal plexus is primarily inhibitory.

Multiple Choice

What are the main functions of the myenteric plexus as described in the image?

• Controlling intestinal smooth muscle activity

• Regulating blood flow

• Stimulating digestive enzyme secretion

• Controlling local intestinal absorption

Open Ended

Explain how the sympathetic nervous system affects gastrointestinal tract activity.

Fill in the Blank

Fill in the blank: The cranial parasympathetic nerve fibers are almost entirely in the ___ nerve.

Multiple Choice

What are the main functions of afferent sensory nerve fibers from the gut?

• Inhibit intestinal movements

• Stimulate intestinal movements

• Transmit signals to the brain

• All of the above

Multiple Choice

What is the role of the parasympathetic nervous system in the gastrointestinal tract?

• Inhibits activity of the enteric nervous system

• Stimulates activity of the enteric nervous system

• Has no effect on the enteric nervous system

• Only affects the stomach

Open Ended

Explain the role of glucose-dependent insulinotropic peptide (GIP) in the gastrointestinal system.

Fill in the Blank

Fill in the blank: Cholecystokinin is secreted by "I" cells in the mucosa of the duodenum and ___ in response to digestive products of fat, fatty acids, and amino acids.

Multiple Choice

Which hormone is secreted by the "S" cells in the mucosa of the duodenum?

• Gastrin

• Cholecystokinin

• Secretin

• Gastric inhibitory peptide

Multiple Choice

What are the primary actions of gastrin in the gastrointestinal tract?

• Stimulates gastric acid secretion

• Inhibits gastric acid secretion

• Stimulates insulin release

• Inhibits intestinal motility

Open Ended

What is peristalsis and how does it function in the gastrointestinal tract?

Open Ended

Explain the role of motilin in gastrointestinal motility.

Multiple Choice

What are the two functional types of movements that occur in the gastrointestinal tract?

• Propulsive movements

• Mixing movements

• Digestive movements

• Absorptive movements

Multiple Select

What are the possible causes of increased blood flow during gastrointestinal activity?

• Release of vasoactive hormones

• Increased muscle activity

• Absorption of nutrients

• Decreased blood flow to the gut

Open Ended

Explain how the blood flow in the gastrointestinal tract changes during digestive activity.

Multiple Choice

What is the role of the portal vein in the splanchnic circulation?

• To transport oxygenated blood to the liver

• To carry nutrients from the gastrointestinal tract to the liver

• To drain blood from the liver to the vena cava

• To supply blood to the spleen

Multiple Choice

The arterial blood supply to the intestines is primarily through which major artery?

• Aorta

• Superior mesenteric

• Inferior mesenteric

• Ileocolic

Multiple Choice

What is the significance of the countercurrent blood flow in the villi?

• Prevents oxygen loss

• Increases nutrient absorption

• Reduces blood flow

• Enhances oxygen delivery

Multiple Choice

What is the role of the parasympathetic nerves in gastrointestinal blood flow?

• Increase blood flow

• Decrease blood flow

• Have no effect

• Only affect the stomach

Multiple Choice

What is the role of sympathetic stimulation in gastrointestinal blood flow during heavy exercise?

• It increases blood flow to the intestines

• It decreases blood flow to the intestines

• It has no effect on blood flow

• It increases glandular secretion

Multiple Choice

The process of chewing is controlled by which part of the brain?

• Cerebral cortex

• Hypothalamus

• Brain stem

• Amygdala

Open Ended

Explain the role of chewing in the digestion of food. Why is it particularly important for fruits and vegetables?

Multiple Choice

What are the two main stages of swallowing as described in the text?

• Voluntary stage

• Involuntary stage

• Mastication stage

• Digestion stage

Open Ended

Describe the involuntary pharyngeal stage of swallowing and its significance in the digestive process.

Multiple Choice

What is the role of the epiglottis during the swallowing process?

• To prevent food from entering the trachea

• To aid in the upward movement of the larynx

• To stimulate the swallowing reflex

• To close the esophagus

Open Ended

What is the role of receptive relaxation in the swallowing process?

Open Ended

Explain the function of the lower esophageal sphincter in the swallowing process.

Multiple Choice

What are the two types of peristalsis involved in swallowing?

• Primary peristalsis

• Secondary peristalsis

• Tertiary peristalsis

• Quaternary peristalsis

Open Ended

Describe the process of mixing and propulsion of food in the stomach as explained in the text.

Fill in the Blank

Fill in the blank: The stomach can accommodate food quantities of up to ___ liters.

Multiple Choice

What is the role of constrictor rings in the stomach during digestion?

• To expel contents through the pylorus

• To mix stomach contents

• To initiate hunger contractions

• To regulate the flow of chyme

Multiple Choice

What are the two major parts of the stomach as described in the anatomical diagram?

• Body

• Antrum

• Fundus

• Pylorus

Open Ended

Describe the effect of the duodenum on stomach emptying as mentioned in the text.

Fill in the Blank

Fill in the blank: The pyloric sphincter is responsible for controlling the passage of ___ into the duodenum.

Multiple Select

What factors promote stomach emptying according to the text?

• Increased gastric volume

• Presence of food in the stomach

• Hormonal signals from the duodenum

• High acidity in the stomach

Multiple Choice

What is the role of the pylorus in controlling stomach emptying?

• It regulates the rate of stomach emptying

• It prevents food particles from mixing

• It increases the pressure in the stomach

• It allows for the absorption of nutrients

Multiple Choice

What are the two types of contractions that occur in the small intestine?

• Mixing contractions and propulsive contractions

• Segmentation contractions and peristaltic contractions

• Circular contractions and longitudinal contractions

• Sphincter contractions and reflex contractions

Open Ended

Explain how the presence of certain breakdown products in the chyme affects gastric emptying.

Multiple Choice

What is the role of cholecystokinin (CCK) in the process of gastric emptying?

• Stimulates gastric emptying

• Inhibits gastric emptying

• Increases stomach acid production

• Decreases bile secretion

Open Ended

Explain the role of the gastroenteric reflex in the small intestine.

Fill in the Blank

Fill in the blank: The maximum frequency of the segmentation contractions in the small intestine is determined by the frequency of electrical slow waves in the intestinal wall, which is the basic electrical rhythm described in Chapter ___.

Multiple Select

What factors affect small intestinal peristalsis?

• Gastrin

• CCK

• Motilin

• Serotonin

Multiple Choice

What are the different types of segmentation movements in the small intestine?

• Regularly spaced

• Isolated

• Irregularly spaced

• Weak regularly spaced

Multiple Choice

What are the principal functions of the colon as described in the text?

• Absorption of water and electrolytes

• Storage of solid feces until it can be expelled

• Mixing movements and propulsion of contents

• All of the above

Open Ended

Describe the feedback control of the ileocecal sphincter and its role in digestion.

Multiple Choice

What is the function of the ileocecal valve in the gastrointestinal system?

• To prevent backflow from the colon to the small intestine

• To absorb nutrients from the chyme

• To store fecal matter until it can be expelled

• To regulate the flow of bile

Fill in the Blank

Fill in the blank: The mass movements in the colon are primarily initiated by the __________ reflexes.

Open Ended

Describe the process of mass movements in the colon and their significance in the digestive system.

Multiple Choice

What are the two types of sphincters that prevent the continual dribble of fecal matter from the anus?

• Internal anal sphincter

• External anal sphincter

• Rectal sphincter

• Gastrocolic sphincter

Open Ended

Explain the role of the external anal sphincter in the defecation process.

Fill in the Blank

The peritoneo________ reflex results from irritation of the peritoneum.

Multiple Choice

What are the different autonomic reflexes that affect bowel activity?

• Duodenocolic reflex

• Gastrocolic reflex

• Enterogastric reflex

• Defecation reflex

Multiple Choice

What type of glands are associated with the alimentary tract?

• Mucous glands

• Salivary glands

• Pancreas

• All of the above

Open Ended

What is the role of mucous glands in the alimentary tract?

Multiple Choice

The presence of food in the gastrointestinal tract stimulates the secretion of juices. What are the three types of stimuli that activate this system?

• Tactile stimulation

• Chemical irritation

• Distension of the gut

• All of the above

Multiple Choice

What stimulates the secretion of the alimentary tract glands?

• Contact of food with the epithelium

• Hormonal signals

• Nervous system signals

• All of the above

Multiple Choice

What are the two primary functions of secretory glands in the gastrointestinal tract?

• Secretion of hormones

• Secretion of digestive enzymes

• Absorption of nutrients

• Protection against pathogens

Open Ended

Explain the basic mechanism of secretion by glandular cells as described in the image.

Multiple Choice

What are the primary secretions of a glandular cell?

• Ptyalin

• Mucus

• Extracellular fluid

• All of the above

Open Ended

Describe the process of secretion in the salivary glands and its significance.

Fill in the Blank

Fill in the blank: Saliva contains ___ which is an enzyme for digesting starches.

Multiple Choice

What is the role of mucus in the gastrointestinal tract?

• Lubrication

• Digestion

• Absorption

• Protection

Multiple Choice

What are the main components of saliva and their functions?

• Electrolytes

• Mucins

• Water

• Digestive enzymes

Open Ended

Explain how the parasympathetic nervous system regulates salivary secretion.

Fill in the Blank

The concentration of potassium ions in saliva is about ___ times greater than in plasma.

Multiple Select

What factors can stimulate salivation according to the text?

• Taste stimuli

• Visual stimuli

• Smell stimuli

• Touch stimuli

Multiple Choice

What is the role of saliva in oral hygiene?

• It helps in digestion

• It contains antibodies

• It provides metabolic support to bacteria

• It prevents tooth decay

Open Ended

Describe the basic mechanism of hydrochloric acid secretion by the parietal cells.

Fill in the Blank

Fill in the blank: The pH of gastric acid is about ___.

Multiple Choice

What is the main function of the oxyntic (parietal) cells in the gastric glands?

• Secrete mucus

• Secrete hydrochloric acid

• Secrete pepsinogen

• Secrete intrinsic factor

Multiple Choice

What are the three types of cells found in the oxyntic (gastric) glands?

• Mucous neck cells

• Peptic (chief) cells

• Oxyntic (parietal) cells

• Intrinsic factor cells

Multiple Choice

The pyloric glands are structurally similar to the oxyntic glands but contain which type of cells?

• Parietal cells

• Mucous cells

• Chief cells

• All of the above

Multiple Choice

What are the basic factors that stimulate gastric secretion?

• Acetylcholine

• Gastrin

• Histamine

• All of the above