Digestive Tract / Hepatobiliary Flashcards
The right pancreatic lobe is closely associated with the _______.
proximal duodenum
The proximal duodenum is the first part of the small intestine, immediately following the stomach.
The right pancreatic lobe is contained within the _______.
mesoduodenum
The mesoduodenum is the peritoneal fold that attaches the duodenum to the posterior abdominal wall. Exposure required retraction of the descending duodenum.
The left pancreatic lobe begins at the _____ and extends along the _____.
pylorus
greater curvature of the stomach
The pylorus is the opening from the stomach into the duodenum.
The left liver lobe is contained within the _______.
dorsal leaf of the greater omentum
The greater omentum is a fold of peritoneum that hangs down from the stomach. Exposure requires retraction of the omentum and stomach cranioventrally.
The body of the pancreas is closely associated with the _______.
proximal duodenum
The body of the pancreas lies between the head and tail, adjacent to the proximal duodenum.
What percentage of the total pancreatic mass is formed by the exocrine portion?
98%
The exocrine portion includes associated vessels, nerves, and ducts. Other portion is endocrine.
What type of cells are pancreatic lobules primarily composed of?
Acinar cells
Acinar cells are part of the exocrine pancreas and synthesize digestive enzymes. Proteases, Amylases, Lipases and Inhibitors.
What are the islands of polygonal cells in the pancreas called?
Islets of Langerhans
The Islets of Langerhans are part of the endocrine pancreas and are associated with acinar cells.
What type of cells secrete glucagon in the pancreas?
Alpha cells
Alpha cells are one of the four distinct polypeptide secreting cell types in the Islets of Langerhans.
What hormone is secreted by Beta cells?
Insulin
Beta cells are involved in glucose metabolism and play a critical role in regulating blood sugar levels.
What hormone do Delta cells produce?
Somatostatin
Somatostatin functions to inhibit the secretion of other hormones and regulate the endocrine system.
What type of cells secrete pancreatic polypeptide?
F or PP cells
Pancreatic polypeptide is involved in regulating both the exocrine and endocrine functions of the pancreas.
Fill in the blank: The Islets of Langerhans are made up of four secreting cell types: Alpha cells, Beta cells, Delta cells, and _______.
F or PP cells
This highlights the diversity of hormone secretion in the pancreatic islets.
What are the four distinct cell types found within the Islets of Langerhans?
- Alpha cells
- Beta cells
- Delta cells
- F or PP cells
Each cell type has a specific hormone they secrete, contributing to various physiological functions.
True or False: Acinar cells are responsible for the secretion of hormones in the pancreas.
False
Acinar cells are responsible for synthesizing digestive enzymes, not hormones.
The majority of the pancreatic blood supply originates from the _______ artery.
**Celiac artery **
Via the splenic and hepatic arteries
The _______ artery is the primary blood supply to the left limb of the pancreas.
splenic
The hepatic artery terminates as the cranial _______ artery.
pancreaticoduodenal
This artery enters the body of the pancreas and supplies the proximal portion of the right limb.
The cranial pancreaticoduodenal artery courses through the _______ portion of the right limb of the pancreas.
proximal
This artery plays a key role in supplying blood to the upper part of the pancreas.
The _______ __________________ artery, a branch of the cranial mesenteric artery, supplies the distal portion of the right limb of the pancreas.
caudal pancreaticoduodenal
The cranial and caudal pancreaticoduodenal arteries _______ within the right limb of the pancreas.
anastomose
Anastomosis refers to the connection between two blood vessels, ensuring adequate blood supply.
The cranial pancreaticoduodenal artery enters the body of the pancreas and courses through the _______ portion of the right limb.
proximal
This artery is vital for maintaining the blood supply to the upper region of the pancreas.
The right limb of the pancreas receives blood supply from the cranial and caudal _______ arteries.
pancreaticoduodenal
These arteries are essential for ensuring that the right limb of the pancreas is adequately perfused.
What composes the pelvic plexus?
- Parasympathetic fibers in the pelvic nerves; branches S1, S2, S3 sacral nerves (somatic);
- Sympathetic fibers in the hypogastric nerves (L1–L4) from the caudal mesenteric ganglion
The pelvic plexus plays a crucial role in the autonomic regulation of the rectum and anus.
What is the function of the parasympathetic fibers of the pelvic plexus in relation to the rectum?
Excitatory
These fibers stimulate rectal activity, facilitating bowel movements.
What is the function of the parasympathetic fibers of the pelvic plexus in relation to the internal anal sphincter?
Inhibitory
This inhibition allows for relaxation of the internal anal sphincter during defecation.
What type of innervation do sympathetic fibers from the hypogastric nerves provide to the rectum?
Inhibitory
Sympathetic fibers generally reduce gastrointestinal motility.
What type of innervation do sympathetic fibers from the hypogastric nerves provide to the internal anal sphincter?
Excitatory
This excitation leads to contraction of the internal anal sphincter, aiding in fecal continence.
Which nerve branch supplies voluntary motor innervation to the external anal sphincter?
Caudal rectal branch of the pudendal nerve
This allows for conscious control over the external anal sphincter.
What type of innervation does the perineal branch provide?
Sensory innervation
This sensory input is important for the perception of rectal filling and the urge to defecate.
What are the circumanal glands?
Located in a subcutaneous zone that radiates up to 4cm outward from anus
Consist of superficial sebaceous portion and deep, nonsebaceous; apocrine and sweat glands are dispersed among these.
Where are the anal glands located?
Zona columnaris
Zona intermedia
Tubuloalveolar glands that produce fatty secretions.
What are the paraanal sinus glands composed of?
Large, coiled, apocrine, sudoriparous tubules
Produce a foul-smelling, serous to pasty liquid. Located in the paranal sinus aka anal sac.
Fill in the blank: The circumanal glands are located in a _______ that radiates up to 4cm outward from the anus.
subcutaneous zone
True or False: The anal glands are external cutaneous glands.
False
Anal glands are located in the internal cutaneous zone.
What type of secretion do paraanal sinus glands produce?
Foul-smelling, serous to pasty liquid
Fill in the blank: The anal glands are _______ that produce fatty secretions.
tubuloalveolar glands
Laterally located; Cranial to the circumanal glands; band of grape-shaped glands 5 mm wide
Name the two main components of the circumanal glands.
- Superficial sebaceous portion
- Deep, nonsebaceous
What is the function of the apocrine and sweat glands in the circumanal glands?
Dispersed among the circumanal glands
They contribute to the glandular secretions.
Fill in the blank: Anal glands are present in the zona _________ and zona _________ of the anal canal.
Fill in the blank: Sebaceous, circumanal, and apocrine sweat glands were restricted to the zona _________.
columnaris
intermedia
cutanea
Three glands of the Anus
Circumanal gland
Anal gland
Paranal sinus gland
Paranal sinus gland are in the anal sac aka paranal sac
What artery initially supplies blood to the bulk of the colon?
cranial mesenteric artery
The cranial mesenteric artery branches into which artery that supplies the colon?
common colic artery
Which artery supplies the cecum?
ileocolic artery
What arteries supply the ascending colon?
ileocolic artery proximally and right colic artery distally
Which arteries supply the transverse colon?
right colic artery proximally and middle colic artery
What artery supplies the proximal half of the descending colon?
middle colic artery
Which artery supplies the distal half of the descending colon?
left colic branch of the caudal mesenteric artery
What artery supplies the most distal portion of the descending colon?
cranial rectal artery as it courses along the mesenteric border to the rectum
What are the threep phases of swallowing?
- oropharyngeal
- esophageal
- gastroesophageal
Which cranial nerves are associated with the oral cavity and pharynx?
Trigeminal nerve (CN V), glossopharyngeal nerve (CN IX), vagus nerve (CN X)
These nerves are connected via the solitary fasciculus (aka solitary tract or tractus solitarius or fasciculus solitarius is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla oblongata).
Where is the swallowing center located?
In the lateral reticular formation
Upper motor neuron
What muscles in regard to the tongue does the Trigeminal nerve (CN V) innervate?
Mylohyoideus and digastricus muscles
These muscles control the elevation of the base of the tongue.
Which cranial nerve innervates the voluntary muscles of the oral cavity?
Facial nerve (CN VII)
What does the Glossopharyngeal nerve (CN IX) innervate?
The Pharynx
Which structures does the Vagus nerve (CN X) innervate?
Pharynx, Larynx (via recurrent laryngeal nerve), Esophagus
What does the Hypoglossal nerve (Cranial Nerve XII) innervate?
The Tongue
What is the nature of the respiratory center mentioned in regardess to swallowing center?
Inhibitory
What percentage of total body protein is produced by the liver?
~20 %
The liver is responsible for producing a significant portion of the body’s protein, including albumin.
Which protein is produced 100% by the liver?
ALB (Albumin)
Albumin is a key protein that helps maintain oncotic pressure and carries various substances in the blood.
What processes does the liver use to maintain plasma glucose levels?
Gluconeogenesis and glycogenolysis
Carbohydrate Metabolism
Which coagulation factors are produced by the liver?
ALL except FVIII and vWF
FVIII (Factor VIII) and vWF (von Willebrand Factor) are produced by vascular endothelium. Some sources has the liver sinusoidal endothelial cells (LSECs) as the primary cells that produce factor VIII in the liver.
What is the role of the reticuloendothelial system (RES) in the liver?
Contributes largest portion of immune function
The RES is involved in phagocytosis and erythrocyte destruction, playing a critical role in the immune system.
Name of macrophages found in the liver?
Kupffer cell
Kupffer cells are specialized macrophages that help in the immune response and detoxification processes.
From what substance is bile synthesized in the liver?
Cholesterol
Bile is essential for digestion and absorption of fats and is produced from cholesterol in the liver.
What substances does the liver clear from the body?
Ammonia, anesthetic agents, drugs
The liver plays a crucial role in detoxifying harmful substances and metabolizing drugs.
What does the liver store?
Glycogen, Fat, vitamins, Zinc, Copper
The liver serves as a storage site for essential nutrients and minerals necessary for various bodily functions.
How much of hepatic function has to be affect to see hypoalbuminea?
70 - 80%
What neuroendocrine change occurs in uncomplicated starvation?
Metabolic rate lowers to decrease nutrient needs
This change helps to conserve energy during periods of starvation.
Which hormone is increased during uncomplicated starvation?
Glucagon
Glucagon plays a key role in maintaining blood glucose levels.
Which hormones are decreased during uncomplicated starvation?
Insulin, catecholamines, and stress hormones
These decreases help shift the body’s metabolism towards fat utilization.
How is blood glucose initially maintained during uncomplicated starvation?
By hepatic glycogenolysis and gluconeogenesis
These processes involve breaking down glycogen and synthesizing glucose from non-carbohydrate sources.
What happens to glycogen stores during uncomplicated starvation?
Glycogen stores are rapidly depleted
This depletion leads to a shift in energy sources.
What becomes the primary source of energy after glycogen stores are depleted?
Fatty acid metabolism produces ketones
Ketones serve as an alternative energy source, especially for the brain.
What does hepatic gluconeogenesis utilize for glucose-dependent tissues?
Amino acids
This process is crucial for maintaining glucose levels for essential functions.
What type of protein is conserved during uncomplicated starvation?
Protein for cardiac and respiratory function
This conservation is vital for sustaining life during starvation.
What are the primary causes of death during uncomplicated starvation?
Respiratory and cardiac failure and bronchopneumonia
These complications arise as the body deteriorates from lack of nutrients.
What happens to the metabolic rate during stress with illness or injury?
Increased
This occurs with no protein conservation and is proportional to the severity of the insult.
What hormonal changes occur during stress?
Increased anti-diuretic hormone, catecholamine, glucagon, and glucocorticoid production
These changes are part of the body’s response to stress.
What system is activated during stress that affects blood pressure?
Renin-angiotensin-aldosterone system
This system plays a key role in regulating blood pressure and fluid balance.
What is the effect on cardiac output during stress?
Decreased
This is a result of various physiological changes during stress.
What happens to peripheral vascular resistance during stress?
Increased
This contributes to the body’s response to stress and can affect blood flow.
What is a relative effect of stress on insulin?
Relative insulin resistance
This can lead to metabolic complications during stress.
What happens to protein catabolism during stress?
Increased
Stress also leads to nitrogen loss and contributes to malnutrition.
What are mediators of inflammation like during stress?
Increased
This can exacerbate the body’s response to injury or illness.
What is the overall effect of stress on metabolic rate?
Increased
This rapid increase can lead to malnutrition if not managed.
What is villous atrophy?
Secondary to malnutrition
A condition characterized by the reduction in the size and number of villi in the intestine, often due to malnutrition.
How quickly does atrophy occur in pigs during fasting?
In as little as 1.5 days.
In piglets on TPN within 1 day
What effect does starvation have on the intestinal epithelial barrier?
It disrupts the barrier, which protects the host from gut-dwelling bacteria.
For how long should enteral feeding not be withheld?
More than 48 hours.
Early initiation of enteral feeding recommended unless specifically contraindicated
What is edema?
Presence of abnormally large amounts of fluid in the intercellular tissue spaces of the body
What are the two types of edema?
Localized and systemic
What can cause localized edema?
Venous obstruction, lymphatic obstruction, or increased vascular permeability
What is ascites?
Fluid accumulation in the peritoneal cavity
What is massive generalized edema called?
Anasarca
What is produced by Parietal cells?
Acids and intrinsic factor
Intrinsic factor is essential for vitamin B12 absorption.
Where are Mucous neck cells located?
Body, antrum
Mucous neck cells secrete mucus.
What do Chief cells produce?
Pepsinogen
Pepsinogen is activated to pepsin in the acidic environment of the stomach.
What is secreted by the Surface epithelium?
Mucus, bicarbonate
These substances help protect the stomach lining from gastric acid.
Which hormones are produced by Endocrine cells?
Gastrin, Histamine, Serotonin
These hormones regulate gastric functions.
Fill in the blank: Parietal cells are located in the _______.
Body
Fill in the blank: Chief cells are primarily found in the _______.
Body
True or False: Mucous neck cells are responsible for producing pepsinogen.
False
Pepsinogen is produced by Chief cells, not Mucous neck cells.
When does the strength of IRA decrease significantly?
Within the first 48 hours
Strength decreases are observed in esophageal (37%), gastroduodenal (64%), small intestine (70%), and colon (72%)
What is the percentage decrease in strength for the esophagus within the first 48 hours?
37%
What is the percentage decrease in strength for the gastroduodenal region within the first 48 hours?
64%
What is the percentage decrease in strength for the small intestine within the first 48 hours?
70%
What is the percentage decrease in strength for the colon within the first 48 hours?
72%
What is the cause of decreased strength in IRA during the first 48 hours?
High collagenase activity on days 0-3
Fill in the blank: On days 0-3 there is a decreased strength in IRA due to _______.
[high collagenase activity]
True or False: The strength of IRA decreases more in the colon than in the esophagus within the first 48 hours.
True
A, Descending duodenum; B, ascending duodenum; C, jejunum; D, ileum; E, cecum; F, ascending colon; G, transverse colon; H, descending colon; I, rectum.
- Abdominal aorta
- cranial mesenteric a.
- middle colic a.
- ileocolic a.
- right colic a.
- colic branch of ileocolic a.
- cecal a.
- antimesenteric ileal branch
- mesenteric ileal branch
- caudal pancreaticoduodenal a.
- jejunal aa.
- phrenicoabdominal aa.
- renal aa.; 14, testicular (ovarian) aa.
- caudal mesenteric a.
- left colic a.
- cranial rectal a.
- cranial pancreaticoduodenal a.
Uncomplicated starvation:
* _____ metabolic rate to ↓ nutrient needs
* ↑ Glucagon, ↓____ and Catecholamines
* Initially Glycogen used for glucose then _____ _____ become primary source of energy
* For organs that need glucose, hepatic gluconeogenesis using proteins – amino acids
* Death takes ____ and is due to respiratory or cardiac failure
Uncomplicated starvation:
* Lower metabolic rate to ↓ nutrient needs
↑ Glucagon, ↓Insulin* and Catecholamines
* Initially Glycogen used for glucose then fatty acids become primary source of energy
* For organs that need glucose, hepatic gluconeogenesis using proteins – amino acids
* Death takes weeks and is due to respiratory or cardiac failure
Stressed Starvation:
* Increased metabolic rate with no _____ conservation
* Increased ______ nervous system (catecholamines, glucagon, glucocorticoids, ADH) → ↓ CO, ↑ vascular resistance, insulin resistance, protein catabolism, inflammation, and rapid malnutrition
Stressed Starvation:
* Increased metabolic rate with no protein conservation
* Increased sympathetic nervous system (catecholamines, glucagon, glucocorticoids, ADH) → ↓ CO, ↑ vascular resistance, insulin resistance, protein catabolism, inflammation, and rapid malnutrition
Villous atrophy:
* Occurs in as little as ____ days of not eating
* Should not withhold feeding >___ hours
Villous atrophy:
* Occurs in as little as 1.5 days of not eating
* Should not withhold feeding >48 hours
