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By the end of this section, you will be able to:
  • Label on a diagram the four main regions of the stomach, its curvatures, and its sphincter
  • Identify the four main types of secreting cells in gastric glands, and their important products
  • Explain why the stomach does not digest itself
  • Describe the mechanical and chemical digestion of food entering the stomach

Although a minimal amount of carbohydrate digestion occurs in the mouth, chemical digestion really gets underway in the stomach. An expansion of the alimentary canal that lies immediately inferior to the esophagus, the stomach links the esophagus to the first part of the small intestine (the duodenum) and is relatively fixed in place at its esophageal and duodenal ends. In between, however, it can be a highly active structure, contracting and continually changing position and size. These contractions provide mechanical assistance to digestion. The empty stomach is only about the size of your fist, but can stretch to hold as much as 4 liters of food and fluid, or more than 75 times its empty volume, and then return to its resting size when empty. Although you might think that the size of a person’s stomach is related to how much food that individual consumes, body weight does not correlate with stomach size. Rather, when you eat greater quantities of food—such as at holiday dinner—you stretch the stomach more than when you eat less.

Popular culture tends to refer to the stomach as the location where all digestion takes place. Of course, this is not true. An important function of the stomach is to serve as a temporary holding chamber. You can ingest a meal far more quickly than it can be digested and absorbed by the small intestine. Thus, the stomach holds food and parses only small amounts into the small intestine at a time. Foods are not processed in the order they are eaten; rather, they are mixed together with digestive juices in the stomach until they are converted into chyme, which is released into the small intestine.

As you will see in the sections that follow, the stomach plays several important roles in chemical digestion, including the continued digestion of carbohydrates and the initial digestion of proteins and triglycerides. Little if any nutrient absorption occurs in the stomach, with the exception of the negligible amount of nutrients in alcohol.

Structure

There are four main regions in the stomach    : the cardia, fundus, body, and pylorus ( [link] ). The cardia    (or cardiac region) is the point where the esophagus connects to the stomach and through which food passes into the stomach. Located inferior to the diaphragm, above and to the left of the cardia, is the dome-shaped fundus    . Below the fundus is the body    , the main part of the stomach. The funnel-shaped pylorus    connects the stomach to the duodenum. The wider end of the funnel, the pyloric antrum    , connects to the body of the stomach. The narrower end is called the pyloric canal    , which connects to the duodenum. The smooth muscle pyloric sphincter    is located at this latter point of connection and controls stomach emptying. In the absence of food, the stomach deflates inward, and its mucosa and submucosa fall into a large fold called a ruga    .

Questions & Answers

Its a fusion of bones where the bones becomes flexible or stiff.. Its a kind of arthritis
rumana Reply
what is ankylosis
Adam Reply
master gland Kon si h
kajal Reply
Pituitary gland
KUNDAN
pituitary gland because it give harmonies and control other gland
ABDULLAH
glands often secrete hormones which play an important role in maintaining homeostasis.
KUNDAN
pituitary gland
Aftab
pituitary gland is master gland because it present in biran and secrtehormones and play other gland of human body and function its gland so that also called master gland.
ABDULLAH
pituitary glandis the master gland of our body
Nadeem
how do you study for A&P? lab and lecture?
Aubrey Reply
depends how your lab exams and lecture exams are structured. but either way, you want to study two weeks before any of the exams. study in a way that you would be teaching it to someone. lec is mostly physio. and a lil' anatomy. lab is all anatomy and motion- so memorization is key.
Berlin
record the lectures in both cases. read the lessons for that class day. have questions. go to office hours. this will help you in A&P- if anything the teacher would give you a little bit of points for making so much of an effort
Berlin
When one is suffering from motion sickness what area of the brain may trigger emesis?
amy Reply
that is the sign of stroke. if the patient have a stroke. the left side of body is weakness, the affected right of cerebrum but if right side of the body is weakness surely in left side!
Larry
thank you sooo much bro
Fatima Reply
helloo
Sentamu
Fatima hw a u
Sentamu
hii
Shubham
any one elaborate fr me foramens of the skull and features which they transmit
Sentamu
icant undrestand plz
zahruuzh Reply
try to read I hop you will understand
state and explain 20 radiology uses
ILYAS Reply
what are chemicals in anatomy and physiology?
Mike Reply
what can I do to find it easy for me in anatomy and physiology course
Mike
study up on the basics of the periodic chart, learn bones and muscles attachments, and learn muscles. Those take the longest to memorize. After that it should be a little easier.
Toni
what are the two types of body cells
Jennifer Reply
what is malnutrition
Claire
malnutrition refers to faulty nutrition resulting from malabsorption,poor diet or overeating. Sometimes too these food do not contain all the six food nutrients in their right proportion.
Yakubu
thank you
Claire
welcome
Yakubu
Will u be malnourished?
Baigwa
gud
Budumari
What's the difference between radiology and radiology
gabriel
Nothing! Radiology it means the study or using of radiation in medical science it can be 1.diagnose or treatment diagnosed radiology! x- ray. ultrasound. ct-scan. mammogram. MRI. 2. treatmen- radiation oncology, like Cobalt 60. and nuclear medicine
Larry
what is X-ray?
Nissar
X-ray is type of light that make it possible to see inside any object. as human body
KUNDAN
How the nervous system develops
ayiesher Reply
From the cells at the back of an embryo
Mma
breifly explain anatomy of thorax
Hadiza Reply
How many region the rib is divided
Konneh
how many bon of human being
Nura
206
John
how to study for the skeletal system
ryaisha
and anatomy
ryaisha
I really need sources immediately
ryaisha
I printed out all the different bones. Put them in the see through protective sheaths and got dry erase markers. I could right on them and erase to help me learn to spell the names of markings and bones.
Toni
Or go to a book store, Barnes and Noble(doesn't have to be this) and they have coloring books for anatomy. $16. Really helpful.
Toni
okay thanks and are what study tools you use to study the materials and get a better understanding
ryaisha
*what are
ryaisha
hiii
Roopa
I prefer diagrams, pictures that lay out each step with the information in each step. For Example: how action potential creates muscles to move. A pictured diagram gives me a better understanding of how each piece plays a role in each step of the process.
Toni
Also for basics, such as memorizing vocab. Flash cards are great. Don't become discouraged if you don't get them all right the first times through. The more you go through them, your brain will remember pieces of information from each and help you to pull out the information 😉
Toni
okay thanks
ryaisha
what is the functions of the lips in human
Momboi Reply
could I say sensation?
Sovilace
kissing
Obrian
for protection
Omar
Lips assist in speech and eating
Cindy
Too many easy questions. Which bones are the axial and appendicular? What are the abbreviations for TEE, TTE, AED, A-Mode, B-Mode, and LTH? What is the difference between hypothalamus and thalamus? Where is the parathyroid located? How many True Ribs do we have?
Sovilace Reply
Transesophageal echocardiography Transthoracic Echocardiography automated external defibrillator brightnees mode Los Hermanos Taverna
Inam
what is anatomy
okello Reply
anatomy is scientific study of body structures and how they relate to each other
Skeater

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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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