The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the
thorax (chest) and
pelvis, in humans and in other
vertebrates. The abdomen is the front part of the abdominal segment of the
torso. The area occupied by the abdomen is called the
abdominal cavity. In
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
s it is the
posterior tagma of the body; it follows the thorax or
cephalothorax.
In humans, the abdomen stretches from the thorax at the
thoracic diaphragm to the pelvis at the
pelvic brim. The pelvic brim stretches from the
lumbosacral joint (the
intervertebral disc between
L5 and
S1) to the
pubic symphysis and is the edge of the
pelvic inlet
The pelvic inlet or superior aperture of the pelvis is a planar surface which defines the boundary between the pelvic cavity and the abdominal cavity (or, according to some authors, between two parts of the pelvic cavity, called lesser pelvis an ...
. The space above this inlet and under the thoracic diaphragm is termed the
abdominal cavity. The boundary of the abdominal cavity is the
abdominal wall in the front and the peritoneal surface at the rear.
In vertebrates, the abdomen is a large
body cavity
A body cavity is any space or compartment, or potential space, in an animal body. Cavities accommodate organs and other structures; cavities as potential spaces contain fluid.
The two largest human body cavities are the ventral body cavity, and ...
enclosed by the abdominal muscles, at front and to the sides, and by part of the
vertebral column at the back. Lower ribs can also enclose ventral and lateral walls. The abdominal cavity is continuous with, and above, the pelvic cavity. It is attached to the
thoracic cavity by the
diaphragm
Diaphragm may refer to:
Anatomy
* Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen
* Pelvic diaphragm or pelvic floor, a pelvic structure
* Urogenital diaphragm or triangular ligament, a pelvic structure
Other
* Diap ...
. Structures such as the
aorta, inferior
vena cava
In anatomy, the venae cavae (; singular: vena cava ; ) are two large veins (great vessels) that return deoxygenated blood from the body into the heart. In humans they are the superior vena cava and the inferior vena cava, and both empty into th ...
and
esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...
pass through the diaphragm. Both the abdominal and pelvic cavities are lined by a serous membrane known as the
parietal peritoneum. This membrane is continuous with the
visceral peritoneum lining the organs. The abdomen in vertebrates contains a number of
organs belonging to, for instance, the
digestive system,
urinary system, and
muscular system.
Contents
The
abdominal cavity contains most organs of the
digestive system, including the
stomach, the
small intestine, and the
colon with its attached
appendix
Appendix, or its plural form appendices, may refer to:
__NOTOC__ In documents
* Addendum, an addition made to a document by its author after its initial printing or publication
* Bibliography, a systematic list of books and other works
* Index (pu ...
. Other digestive organs are known as the accessory digestive organs and include the
liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...
, its attached
gallbladder, and the
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an ...
, and these communicate with the rest of the system via various ducts. The
spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . , and organs of the
urinary system including the
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
s, and
adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex ...
s also lie within the abdomen, along with many blood vessels including the
aorta and
inferior vena cava. The
urinary bladder,
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
,
fallopian tubes, and
ovaries
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
may be seen as either abdominal organs or as pelvic organs. Finally, the abdomen contains an extensive membrane called the
peritoneum. A fold of peritoneum may completely cover certain organs, whereas it may cover only one side of organs that usually lie closer to the abdominal wall. This is called the
retroperitoneum, and the kidneys and ureters are known as ''retroperitoneal'' organs.
Abdominal organs can be highly specialized in some animals. For example, the stomach of
ruminants, (a
suborder of mammals that includes
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Adult females are referred to as cows and adult ...
and
sheep), is divided into four chambers –
rumen,
reticulum,
omasum and
abomasum.
Sobo 1906 393.png, View of the various organs and blood-vessels in proximity with liver.
Gray1120.png, The relations of the viscera and large vessels of the abdomen, seen from behind.
Muscles
There are three layers of muscles in the
abdominal wall. They are, from the outside to the inside:
external oblique
The abdominal external oblique muscle (also external oblique muscle, or exterior oblique) is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
Structure
The external oblique is situated on the lateral ...
,
internal oblique, and
transverse abdominal
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (front and side) abdominal wall which is deep to (layered below) th ...
.
The first three layers extend between the
vertebral column, the lower ribs, the
iliac crest and
pubis of the
hip. All of their fibers merge towards the midline and surround the
rectus abdominis in a sheath before joining up on the opposite side at the
linea alba. Strength is gained by the criss-crossing of fibers, such that the
external oblique
The abdominal external oblique muscle (also external oblique muscle, or exterior oblique) is the largest and outermost of the three flat abdominal muscles of the lateral anterior abdomen.
Structure
The external oblique is situated on the lateral ...
runs downward and forward, the
internal oblique upward and forward, and the transverse abdominal horizontally forward.
The
transverse abdominal
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (front and side) abdominal wall which is deep to (layered below) th ...
muscle is flat and triangular, with its fibers running horizontally. It lies between the internal oblique and the underlying
transverse fascia. It originates from the inguinal ligament, costal cartilages 7-12, the iliac crest and thoracolumbar fascia. Inserts into the conjoint tendon, xiphoid process, linea alba and the pubic crest.
The
rectus abdominis muscles are long and flat. The muscle is crossed by three fibrous bands called the
tendinous intersections. The rectus abdominis is enclosed in a thick sheath, formed as described above, by fibers from each of the three muscles of the lateral abdominal wall. They originate at the
pubis bone
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ...
, run up the abdomen on either side of the linea alba, and insert into the cartilages of the fifth, sixth, and seventh ribs. In the region of the
groin, the
inguinal canal, is a passage through the layers. This gap is where the
testes can drop through the wall and where the fibrous cord from the
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
in the female runs. This is also where weakness can form, and cause
inguinal hernia
An inguinal hernia is a hernia (protrusion) of abdominal-cavity contents through the inguinal canal. Symptoms, which may include pain or discomfort especially with or following coughing, exercise, or bowel movements, are absent in about a thir ...
s.
The
pyramidalis muscle
The pyramidalis muscle is a small triangular muscle, anterior to the rectus abdominis muscle, and contained in the rectus sheath.
Structure
The pyramidalis muscle is part of the anterior abdominal wall. Inferiorly, the pyramidalis muscle attache ...
is small and triangular. It is located in the lower abdomen in front of the rectus abdominis. It originates at the pubic bone and is inserted into the linea alba halfway up to the
navel
The navel (clinically known as the umbilicus, commonly known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, altho ...
.
Function
Functionally, the human abdomen is where most of the digestive tract is placed and so most of the absorption and digestion of food occurs here. The alimentary tract in the abdomen consists of the lower
esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to t ...
, the
stomach, the
duodenum, the
jejunum,
ileum, the
cecum and the
appendix
Appendix, or its plural form appendices, may refer to:
__NOTOC__ In documents
* Addendum, an addition made to a document by its author after its initial printing or publication
* Bibliography, a systematic list of books and other works
* Index (pu ...
, the
ascending
''Ascending'' is a science fiction novel by the Canadian writer James Alan Gardner, published in 2001 by HarperCollins Publishers under its various imprints.HarperCollins, Avon, HarperCollins Canada, SFBC/Avon; paperback edition 2001, Eos Books. ...
,
transverse
Transverse may refer to:
*Transverse engine, an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle
* Transverse flute, a flute that is held horizontally
* Transverse force (or ''Euler force''), the tange ...
and
descending colons, the
sigmoid colon and the
rectum. Other vital organs inside the abdomen include the
liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...
, the
kidneys, the
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an ...
and the
spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . .
The
abdominal wall is split into the posterior (back), lateral (sides), and anterior (front) walls.
Movement, breathing and other functions
The abdominal muscles have different important functions. They assist as
muscles of exhalation in the breathing process during
forceful exhalation
The muscles of respiration are the muscles that contribute to inhalation and exhalation, by aiding in the expansion and contraction of the thoracic cavity. The diaphragm and, to a lesser extent, the intercostal muscles drive respiration during q ...
. Moreover, these muscles serve as protection for the inner organs. Furthermore, together with the back muscles they provide postural support and are important in defining the form. When the
glottis is closed and the
thorax and
pelvis are fixed, they are integral in the
cough,
urination,
defecation, childbirth,
vomit, and singing functions.
When the pelvis is fixed, they can initiate the movement of the trunk in a forward motion. They also prevent
hyperextension. When the thorax is fixed, they can pull up the pelvis and finally, they can bend the vertebral column sideways and assist in the trunk's rotation.
Posture
The transverse abdominis muscle is the deepest muscle, therefore, it cannot be touched from the outside. It can greatly affect the body's posture. The internal obliques are also deep and also affect body posture. Both of them are involved in rotation and lateral flexion of the
spine
Spine or spinal may refer to:
Science Biology
* Vertebral column, also known as the backbone
* Dendritic spine, a small membranous protrusion from a neuron's dendrite
* Thorns, spines, and prickles, needle-like structures in plants
* Spine (zoolo ...
and are used to bend and support the spine from the front. The external obliques are more superficial and they are also involved in rotation and lateral flexion of the spine. Also they stabilize the spine when upright. The rectus abdominis muscle is not the most superficial abdominal muscle. The tendonous sheath extending from the external obliques cover the rectus abdominis. The rectus abdominis is the muscle that very fit people develop into the 6-pack ab look. Although it should really be a 10 pack as there are 5 vertical sections on each side. The 2 bottom sections are just above the pubic bone and usually not visible, hence, the 6 pack abs. The rectus abdominals' function is to bend one's back forward (flexion). The main work of the abdominal muscles is to bend the spine forward when contracting concentrically.
Society and culture
Social and cultural perceptions of the outward appearance of the abdomen has varying significance around the world. Depending on the type of society,
excess weight can be perceived as an indicator of wealth and prestige due to excess food, or as a sign of poor health due to lack of exercise. In many cultures, bare abdomens are distinctly sexualized and perceived similarly to
breast cleavage.
Exercise
Being key elements of spinal support, and contributors to good posture, it is important to properly exercise the abdominal muscles together with the back muscles because when these are weak or overly tight they can suffer painful spasms and
injuries. When properly exercised, abdominal muscles contribute to improved posture and balance, reduce the likelihood of
back pain episodes, reduce the severity of back pain, protect against injury by responding efficiently to stresses, help avoid some back surgeries, and help with the healing of back problems, or after spine surgery. When strengthened, the abdominal muscles provide flexibility as well. The abdominal muscles can be worked by practicing disciplines of general body strength such as
Pilates,
yoga
Yoga (; sa, योग, lit=yoke' or 'union ) is a group of physical, mental, and spiritual practices or disciplines which originated in ancient India and aim to control (yoke) and still the mind, recognizing a detached witness-consciou ...
,
T'ai chi, and
jogging. There are also specific routines which target each of these muscles.
Clinical significance
Abdominal obesity
Abdominal obesity, also known as central obesity and truncal obesity, is a condition when excessive visceral fat around the stomach and abdomen has built up to the extent that it is likely to have a negative impact on health. Abdominal obesity h ...
is a condition where
abdominal fat
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...
or visceral fat, has built up excessively between the abdominal organs. This is associated with a higher risk of
heart disease,
asthma
Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...
and
type 2 diabetes.
Abdominal trauma is an injury to the abdomen and can involve damage to the abdominal organs. There is an associated risk of
severe blood loss and
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...
.
Injury to the lower chest can cause injuries to the spleen and liver.
A scaphoid abdomen is when the abdomen is sucked inwards. In a newborn, it may represent a
diaphragmatic hernia. In general, it is indicative of
malnutrition.
Disease
Many
gastrointestinal diseases affect the abdominal organs. These include
stomach disease,
liver disease,
pancreatic disease Pancreatic diseases are diseases that affect the pancreas, an organ in most vertebrates and in humans and other mammals located in the abdomen. The pancreas plays a role in the digestive and endocrine system, producing enzymes which aid the digesti ...
,
gallbladder and
bile duct
A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates.
Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. ...
disease; intestinal diseases include
enteritis,
coeliac disease,
diverticulitis, and
IBS.
Examination
Different
medical procedures can be used to examine the organs of the gastrointestinal tract. These include
endoscopy,
colonoscopy,
sigmoidoscopy,
enteroscopy,
oesophagogastroduodenoscopy
Esophagogastroduodenoscopy (EGD) or oesophagogastroduodenoscopy (OGD), also called by various other names, is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum. It is considered ...
and
virtual colonoscopy. There are also a number of
medical imaging techniques that can be used. Surface landmarks are important in the
examination of the abdomen.
Surface landmarks
In the mid-line a slight furrow extends from the
xiphoid process above to the
pubic symphysis below, representing the
linea alba in the abdominal wall. At about its midpoint sits the umbilicus or
navel
The navel (clinically known as the umbilicus, commonly known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, altho ...
. The
rectus abdominis on each side of the linea alba stands out in muscular people. The outline of these muscles is interrupted by three or more transverse depressions indicating the
tendinous intersections. There is usually one about the xiphoid process, one at the navel, and one in between. It is the combination of the linea alba and the tendinous intersections which form the abdominal "six-pack" sought after by many people.
The upper lateral limit of the abdomen is the subcostal margin (at or near the ''
subcostal plane'') formed by the cartilages of the
false rib
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The sternum, together known as the thoracic cage, is a semi- ...
s (8, 9, 10) joining one another. The lower lateral limit is the anterior crest of the
ilium and
Poupart's ligament, which runs from the anterior superior spine of the ilium to the spine of the
pubis. These lower limits are marked by visible grooves. Just above the pubic spines on either side are the external abdominal rings, which are openings in the muscular wall of the abdomen through which the
spermatic cord emerges in the male, and through which an
inguinal hernia
An inguinal hernia is a hernia (protrusion) of abdominal-cavity contents through the inguinal canal. Symptoms, which may include pain or discomfort especially with or following coughing, exercise, or bowel movements, are absent in about a thir ...
may rupture.
One method by which the location of the abdominal contents can be appreciated is to draw three horizontal and two vertical lines.
=Horizontal lines
=
* The highest of the former is the
transpyloric line
The transpyloric plane, also known as Addison's plane, is an imaginary horizontal plane, located halfway between the suprasternal notch of the manubrium and the upper border of the symphysis pubis at the level of the first lumbar vertebrae, L1. It ...
of C. Addison, which is situated halfway between the
suprasternal notch and the top of the pubic symphysis, and often cuts the pyloric opening of the stomach an inch to the right of the mid-line. The
hilum of each
kidney
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
is a little below it, while its left end approximately touches the lower limit of the
spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . . It corresponds to the first lumbar vertebra behind.
* The second line is the ''
subcostal line'', drawn from the lowest point of the
subcostal arch (
tenth rib
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The sternum, together known as the thoracic cage, is a ...
). It corresponds to the upper part of the third lumbar vertebra, and it is an inch or so above the umbilicus. It indicates roughly the
transverse colon, the lower ends of the kidneys, and the upper limit of the transverse (3rd) part of the
duodenum.
* The third line is called the ''
intertubercular line'', and runs across between the two rough
tubercles, which can be felt on the outer lip of the crest of the ilium about from the anterior superior spine. This line corresponds to the body of the fifth lumbar vertebra, and passes through or just above the
ileo-caecal valve, where the
small intestine joins the
large intestine.
=Vertical lines
=
The two vertical or mid-Poupart lines are drawn from the point midway between the anterior superior spine and the pubic symphysis on each side, vertically upward to the costal margin.
* The right one is the most valuable, as the
ileo-caecal valve is situated where it cuts the intertubercular line. The orifice of the
appendix
Appendix, or its plural form appendices, may refer to:
__NOTOC__ In documents
* Addendum, an addition made to a document by its author after its initial printing or publication
* Bibliography, a systematic list of books and other works
* Index (pu ...
lies an inch lower, at
McBurney's point. In its upper part, the vertical line meets the transpyloric line at the lower margin of the ribs, usually the ninth, and here the
gallbladder is situated.
* The left mid-Poupart line corresponds in its upper three-quarters to the inner edge of the
descending colon.
The right subcostal margin corresponds to the lower limit of the
liver
The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...
, while the right nipple is about half an inch above its upper limit.
Quadrants and regions
The abdomen can be divided into quadrants or regions to describe the location of an organ or structure. Classically, quadrants are described as the left upper, left lower, right upper, and right lower. Quadrants are also often used in describing the site of an abdominal pain.
The abdomen can also be divided into nine regions.
These terms stem from "hypo" meaning "below" and "epi" means "above", while "chondron" means "cartilage" (in this case, the cartilage of the rib) and "gaster" means stomach. The reversal of "left" and "right" is intentional, because the anatomical designations reflect
the patient's own right and left.)
The "right iliac fossa" (RIF) is a common site of pain and tenderness in patients who have
appendicitis. The fossa is named for the underlying
iliac fossa of the
hip bone, and thus is somewhat imprecise. Most of the anatomical structures that will produce pain and tenderness in this region are not in fact in the concavity of the ileum. However, the term is in common usage.
Other animals
In
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
s the abdomen is built up of a series of upper plates known as
tergites and lower plates known as
sternite
The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen.
In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case th ...
s, the whole being held together by a tough yet stretchable membrane.
The abdomen contains the insect's digestive tract and reproductive organs, it consists of eleven segments in most orders of insects though the eleventh segment is absent in the adult of most higher orders. The number of these segments does vary from species to species with the number of segments visible reduced to only seven in the common
honeybee. In the
Collembola
Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called ...
(Springtails) the abdomen has only six segments.
The abdomen is sometimes highly modified. In
Apocrita (bees, ants and wasps), the first segment of the abdomen is fused to the
thorax and is called the
propodeum. In
ants the second segment forms the narrow
petiole. Some ants have an additional
postpetiole segment, and the remaining segments form the bulbous
gaster.
The petiole and gaster (abdominal segments 2 and onward) are collectively called the
metasoma
The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. In insects, it contains most of the digestive tract, respiratory system, and cir ...
.
Unlike other arthropods, insects possess no legs on the abdomen in adult form, though the
Protura do have rudimentary leg-like appendages on the first three abdominal segments, and
Archaeognatha
The Archaeognatha are an order of apterygotes, known by various common names such as jumping bristletails. Among extant insect taxa they are some of the most evolutionarily primitive; they appeared in the Middle Devonian period at about the sa ...
possess small, articulated "styli" which are sometimes considered to be rudimentary appendages. Many larval insects including the
Lepidoptera and the
Symphyta (Sawflies) have fleshy appendages called
prolegs on their abdominal segments (as well as their more familiar thoracic legs), which allow them to grip onto the edges of plant leaves as they walk around.
In
arachnids (spiders, scorpions and relatives), the term "abdomen" is used interchangeably with "
opisthosoma
The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to ...
" ("hind body"), which is the body section posterior to that bearing the legs and head (the prosoma or
cephalothorax).
See also
*
Abdominal fat
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...
References
External links
*
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Animal anatomy
Human anatomy