Lesson 77: Structure and function of the Liver

What is another name for the liver?

Hepar.

What is the largest organ/gland in the animal body?

The liver.

What is the most cranial organ in the abdominal cavity?

The liver.

Where is the liver located in the abdominal cavity relative to other organs?

Between the diaphragm and the stomach.

How is the liver generally oriented?

Transversely.

What are the two main surfaces of the liver?

Parietal (Cranial) and visceral (Caudal) surfaces.

Which structure ventrally relates to the liver and covers part of it?

Xiphoid cartilage.

An enlarged liver may extend caudally beyond what anatomical landmark?

The costal arch on the ventrolateral aspect.

In the peritoneal cavity, how is the liver distributed between the right and left sides?

Distributed on right and left (3:2) halves.

What are the general boundaries of the liver on the left side (intercostal space)?

From 7th to 9th ICS / 7th to 10th ribs.

Name three aspects of metabolic regulation performed by the liver

Carbohydrate Metabolism, Lipid Metabolism, and Protein Metabolism.

What general function involves the metabolism of toxins, drugs, and environmental compounds?

Detoxification.

How does the liver metabolize drugs?

Primarily through enzymatic reactions.

What product of the liver is essential for the emulsification and digestion of fats?

Bile.

Where is bile stored in species that have one?

The gallbladder.

Name two types of proteins synthesized by the liver

Albumin and coagulation factors.

Name four nutrients and vitamins stored by the liver

Glycogen, fat-soluble vitamins (A, D, E, K), vitamin B12, and minerals like iron and copper.

What specific cells in the liver contribute to immune functions?

Kupffer cells.

What role does the liver play in ruminants regarding volatile fatty acids?

It is key in processing volatile fatty acids from ruminal fermentation.

Name the four basic lobes of the mammalian liver

Right lobe, Left lobe, Quadrate lobe, and Caudate lobe.

Name two extended parts (processes) of the caudate lobe

Caudate process and Papillary process.

What notch is found on the dorsal border of the left side of the liver?

Esophageal notch.

What notch is found on the dorsal border on the right side of the liver?

Notch for the caudal vena cava.

Where is the gallbladder typically located on the visceral surface?

Between the right and quadrate lobe.

What structures lie between the left and quadrate lobes on the ventral border?

Falciform and round ligament.

What is the term for the opening through which vessels and structures enter the liver?

Hilus.

What structure collectively forms the "root" of the liver?

Hepatic portal vein, hepatic artery, bile duct, lymphatic vessels, and nerves.

What is the smaller division of a liver lobe called?

Lobule.

Which domestic animal's liver clearly shows defined lobules on its surface?

The pig liver.

What are the divisions of the right lobe in the dog?

Right lateral and medial lobes.

What are the divisions of the left lobe in the dog?

Left lateral and medial lobes.

Name the two processes of the caudate lobe in the canine liver

Caudate process of the caudate lobe and Papillary process of the caudate lobe.

Name the blood vessel that carries functional blood supply to the liver (part of the root)

Hepatic Portal vein.

Name the blood vessel that carries arterial blood supply to the liver (part of the root)

Hepatic Artery.

What ligament attaches the liver to the diaphragm in a semicircular/curved manner?

The coronary ligament.

What two ligaments, left and right, attach the liver to the diaphragm?

The triangular ligaments.

What ligament is a median attachment to the diaphragm and abdominal floor?

The falciform ligament.

The falciform ligament is a remnant of what embryonic structure?

The ventral mesentery/ventral connecting peritoneum.

What specific term refers to the remnant of the fetal umbilical vein?

The round ligament (teres ligament).

What structure lies between the stomach and the liver?

The lesser omentum.

The Hepatic artery, which supplies fully oxygenated blood, originates from which larger artery?

Celiac Artery.

The Celiac Artery also gives rise to which other artery supplying the gallbladder?

Cystic artery.

What is the functional blood supply to the liver?

The Hepatic Portal Vein.

The Hepatic Portal Vein carries blood from which three organs/areas?

Digestive tract, pancreas, and spleen.

What vessels provide the venous drainage of the liver?

Hepatic veins.

Where do the Hepatic veins open?

Into the CVC (Caudal Vena Cava).

Where does the CVC pass relative to the liver?

Along the dorsal border of the liver.

What term describes an abnormal connection between the Hepatic Portal System and the Systemic Circulation?

Portocaval/Portosystemic shunt.

Sympathetic innervation of the stomach originates from which spinal cord segments?

Thoracolumbar (T5–L2) spinal cord.

Sympathetic preganglionic fibers for the stomach travel via which nerves?

The splanchnic nerves.

Where do the sympathetic preganglionic fibers for the stomach synapse?

In the right celiac ganglion (part of the celiac plexus).

Parasympathetic innervation to the stomach and liver originates from which structure in the medulla oblongata?

The dorsal motor nucleus of the Vagus n..

What nerve trunk provides parasympathetic and sensory innervation to the liver?

Ventral Vagal trunk.

In the cat liver, how do the caudate and papillary processes compare in size to the dog?

Both are larger.

In relation to the ribcage, how is the cat liver typically situated?

Smaller liver, completely enclosed within the ribcage.

The cat liver has a deeper impression related to what organ?

Deeper renal impression.

Relative to the median plane, where is the ruminant liver mainly located?

Mainly right to the median plane.

By how many degrees is the ruminant liver rotated?

Rotated 90 degrees.

In the ruminant, where is the left lobe situated?

Cranioventral.

In the ruminant, where is the right lobe situated?

Caudo-dorsal.

What impression is deep on the ox liver but shallow in sheep?

Esophageal impression.

Describe the shape of the gallbladder in the ox (cattle)

Pear-shaped.

Describe the shape of the gallbladder in the sheep

Elongated.

What impression is found on the caudate process of the ruminant liver?

Renal impression.

Name three large impressions found on the visceral surface of the ruminant liver

Omasal, reticular, and abomasal impressions.

Why does the pig liver have no renal impression in the caudate lobe?

It is the only domestic mammal in which the liver has no contact with the right kidney.

How is the shape of the equine liver described?

Asymmetrical.

What happens to the right lobe of the equine liver with age?

It atrophies.

What causes the atrophy of the right lobe in horses?

Pressure from the right dorsal colon.

What anatomical structure is absent in the horse liver?

The Gall bladder.

What process is absent in the equine liver?

No papillary process.

How is the round (teres) ligament described in the horse?

Strong and well formed.

Name three impressions found on the visceral surface of the equine liver

Stomach, duodenal, and colic impressions.

What is the opening of the common bile duct into the duodenum called?

Major Duodenal papilla.

Name the smallest starting point for bile flow within the liver

Bile canaliculi.

In the dog, how do the bile duct and pancreatic duct open into the duodenum?

Via a single opening but opening separately.

What unique feature distinguishes the cat's biliary system regarding the ducts?

The pancreatic duct joins the common bile duct.

Since the horse lacks a gallbladder, how is the bile duct described?

It has a wide lumen.

In the horse, the bile duct and major pancreatic duct open together into what structure?

The hepaticopancreatic ampulla.

What anatomical feature in the horse acts as a valve for the bile duct opening?

Oblique passage of duct through wall.