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By the end of this section, you will be able to:
  • State the main digestive roles of the liver, pancreas, and gallbladder
  • Identify three main features of liver histology that are critical to its function
  • Discuss the composition and function of bile
  • Identify the major types of enzymes and buffers present in pancreatic juice

Chemical digestion in the small intestine relies on the activities of three accessory digestive organs: the liver, pancreas, and gallbladder ( [link] ). The digestive role of the liver is to produce bile and export it to the duodenum. The gallbladder primarily stores, concentrates, and releases bile. The pancreas produces pancreatic juice, which contains digestive enzymes and bicarbonate ions, and delivers it to the duodenum.

Accessory organs

This diagram shows the accessory organs of the digestive system. The liver, spleen, pancreas, gallbladder and their major parts are shown.
The liver, pancreas, and gallbladder are considered accessory digestive organs, but their roles in the digestive system are vital.

The liver

The liver    is the largest gland in the body, weighing about three pounds in an adult. It is also one of the most important organs. In addition to being an accessory digestive organ, it plays a number of roles in metabolism and regulation. The liver lies inferior to the diaphragm in the right upper quadrant of the abdominal cavity and receives protection from the surrounding ribs.

The liver is divided into two primary lobes: a large right lobe and a much smaller left lobe. In the right lobe, some anatomists also identify an inferior quadrate lobe and a posterior caudate lobe, which are defined by internal features. The liver is connected to the abdominal wall and diaphragm by five peritoneal folds referred to as ligaments. These are the falciform ligament, the coronary ligament, two lateral ligaments, and the ligamentum teres hepatis. The falciform ligament and ligamentum teres hepatis are actually remnants of the umbilical vein, and separate the right and left lobes anteriorly. The lesser omentum tethers the liver to the lesser curvature of the stomach.

The porta hepatis    (“gate to the liver”) is where the hepatic artery    and hepatic portal vein    enter the liver. These two vessels, along with the common hepatic duct, run behind the lateral border of the lesser omentum on the way to their destinations. As shown in [link] , the hepatic artery delivers oxygenated blood from the heart to the liver. The hepatic portal vein delivers partially deoxygenated blood containing nutrients absorbed from the small intestine and actually supplies more oxygen to the liver than do the much smaller hepatic arteries. In addition to nutrients, drugs and toxins are also absorbed. After processing the bloodborne nutrients and toxins, the liver releases nutrients needed by other cells back into the blood, which drains into the central vein and then through the hepatic vein to the inferior vena cava. With this hepatic portal circulation, all blood from the alimentary canal passes through the liver. This largely explains why the liver is the most common site for the metastasis of cancers that originate in the alimentary canal.

Questions & Answers

how many type of system
Pathias Reply
Two types
Musoke
Respiratory system and Circulatory system
Musoke
6 types of systems
Bkv
Namely:?
Musoke
integumentary system, cardiovascular system, nervous system, digestive system, endocrine system, urinary system.
Atabong
there are many more
Atabong
Thanx
Musoke
What is anatomy !?
Arun Reply
the study of different parts of body to discover situation structure and economy
Aurelia
Anatomy is a study of structure of the body parts and it's consistents. Anatomy is a Greek word which means to cut up
Asma
Which book is perfect for anatomy ? among BD , Vishram , Gray's !?
Arun
iama Student of 1st year
Arun
Ashalata Anatomy text book
Johanna
The study of various body structures and their relationship with one another
Onwochie
Ross and Wilson's anatomy textbook
Onwochie
Anatomy is the study of human structure, functions and other relative organs in the system
Ayorinde
ross and willson book
Tifu
the study of structure unite of body
Faisal
thanks to all
Arun
Does anyone Read A.K dutta?
Arun
refer to the study of human body structure
SAID
Anatomy is study of internal structures of organisms as seen by naked eye
Bkv
which nerve orginates from pons
Kripa Reply
trigeminal nerve
madhuri
demand and supply rules
jamac Reply
compative demand and supply
jamac
compare demand and supply
jamac
what are simple epithelial tissues
Ushie Reply
is a type of tissue which covers the external and internal part of the body
Fatou
more information would be better understanding.
Tasha
It consist of a single layer of identical cells
Bkv
what is platelets
Lilian Reply
platelet is also known as thrombocyte.thrombo means clot.it is a formed element of blood formed from fragment of megakaryocyte surrounded by plasma membrane in the redbone marow
Adeyemo
what is diabetes insipidus
namrata Reply
it is an infection due to less or no secretion of ADH characterized by excretion of dilute urine
Meshack
Infection? I don't think any form of diabetes, whether it's mellitus or insipidus, is caused by an infection.
Matias
ya
Akanyijuka
it is the disorder of salt & water metabolism
Emma
diabetes inspidus is a condition were the liver can't produce insulin to convert the excess sugar to glycogen.
mangs
sorry that is for diabetes mellitus
mangs
what is septal cartilage
Arthur Reply
I don't understand please
Esther Reply
hey
Austine
good evening boss
Austine
Evening
Esther
good evening
Melissa
evening
Vitus
hi
Rodgers
good morning
Aurelia
hello
Helsa
you guys are from ?
Aurelia
Philippines
Helsa
im from india
Aurelia
Hello
Amos
why
Sami
wat
Rodgers
what's that
Gift
what's the medulla?
alhussiney Reply
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum
Ludmila
define bone in simple terms
Mhoses Reply
bones are made up by collagen and calcium phosphate
Aurelia
yes
Confidence
Bones are the hard large calcareous connective tissue of which the adult skeleton of most vertebrates is chiefly composed
Olalekan
Bone is the substance that forms skeleton
Frances
good morning
Mrinal
Skelton muscles is any disorder of calcium
Mrinal
Bones protect the various organs of the body
Celina
Bone is a hard strong and durable type of connective tissue
Bkv
bone is a hard, calcareous connective tissue which gives structural support to the body and helpless in its locomotion!
Divya
It also is the main site for synthesis of the RBCs
Divya
thanks for your answers
Mhoses
A diagram of epithelial tissue
Emmanuel Reply
What does the urinary regulate blood pressure
Jennifer Reply
functions of melatonin
marion Reply
d. inversely proportional
John Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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