Anatomical Position

When an biology is in its conventional anatomical position, positional descriptive terms are provided to indicate regions and features.

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Key Takeaways

Key PointsIn traditional anatomical position, the limbs are placed likewise to the supine position applied on cadavers throughout autopsy.The anatomical place of the skull is the Frankfurt plane. In this position, the reduced margins the the orbitals (eye sockets), the lower margin of the orbits, and also the top margins the the ear canals (poria) lie in the exact same horizontal plane.Because animals can readjust orientation v respect to your environments and also appendages can readjust position v respect come the body, positional descriptive terms refer to the organism only in its standard anatomical place to stop confusion.Key Termsappendage: A limb of the body.supine: lying on the back, reclined.anatomical position: The standard position in i m sorry the body is standing with feet together, eight to the side, and head, eyes, and also palms dealing with forward.

The require for Standardization

Standard anatomical place is the body orientation provided when explicate an organism’s anatomy. Standardization is important to avoid confusion because most organisms can take on plenty of different positions that may change the relative placement the organs. All descriptions describe the biology in its conventional anatomical position, even when the organism’s appendages space in an additional position. Thus, the conventional anatomical position provides a “gold standard” as soon as comparing the anatomy of different members that the same species.


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Relative place in the anatomical position: many terms are offered to define relative place on the body. Cranial ad to functions closer come the head, when caudal refers to attributes closer to the feet. The prior of the body is described as anterior or ventral, if the ago is referred to as posterior or dorsal. Proximal and distal define relative position on the limbs. Proximal describes a function that is closer to the torso, if distal refers to a feature that is closer to the fingers/toes. Medial and also lateral express to place relative to the midline, which is a upright line attracted through the center of the forehead, down through the belly button to the floor. Medial suggests a function is closer come this line, when lateral indicates features further native this line.


Standard Anatomical position in Humans

The conventional anatomical place is agreed upon by the worldwide medical community. In this position, a human being is stand upright through the reduced limbs with each other or slightly apart, feet level on the floor and facing forward, top limbs in ~ the sides v the palms encountering forward and also thumbs pointing far from the body, and head and also eyes directed right ahead. In addition, the arms room usually put slightly except the human body so that the hands do not touch the sides. The location of the limbs, specifically the arms, have crucial implications for directional terms in those appendages.

The basis because that the conventional anatomical place in humans originates from the supine position offered for assessing human cadavers throughout autopsies. Dissection that cadavers was one of the major ways people learned about anatomy transparent history, i m sorry has tremendously influenced the ways through which anatomical understanding has occurred into the scientific ar of today.


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Standard anatomical position: The areas of the body in typical anatomical position, in i m sorry the human body is erect.


In humans, the typical anatomical place of the skull is dubbed the Frankfurt plane. In this position, the orbitales (eye sockets), lower margins that the orbits, and the poria (ear canal upper margins) all lie in the very same horizontal plane. This orientation represents the place of the skull if the topic were standing upright and also looking directly ahead.

It is vital to note that all anatomical descriptions are based upon the conventional anatomical place unless otherwise stated.


Directional Terms

Positional state give specific descriptions the anatomical relationships and enable for consistency as soon as referencing anatomical positions.


Learning Objectives

Identify the anatomical state that define the person body in space


Key Takeaways

Key PointsDescriptions of directional state include: a) remarkable (head) and also inferior (caudal), b) anterior and also posterior, c) lateral and medial, d) deep and superficial, e) proximal and distal, and f) dorsal and ventral.Directional terms provide comparison of anatomical position by to compare the areas of various structures in the body.Key Termsdirectional terms: Directional terms space words provided to define the place of an anatomical structure by compare its place to other structures within the body or within the orientation of the human body itself.

Navigating Anatomy v Language

Directional terms provide an exact descriptions that a structure’s location. They enable a description of anatomical position by comparing place relative to other structures or within the remainder of the body. Traditional anatomical terms because that direction include:

Superior and also inferior (cranial and also caudal) are used when referring to parts of the human body which room toward an end of the body. Superior structures are toward the head (cranial) while inferior (caudal) structures space toward the feet. Examples include the superior and inferior vena cava, which lug deoxygenated blood away from the head (superior) and also from the reduced body (inferior) come the heart.Anterior and also posterior are sometimes used in location of superior and also inferior, respectively. These words space used more often for pet anatomy and also rarely and only with very specific meaning in human being anatomy. Anterior describes the side of the structure facing up in the traditional anatomical place while posterior refers to the bottom side. Because that example, the pituitary gland has an anterior and also posterior side, every of which secretes different species of hormones.Dorsal and also ventral are periodically used in ar of anterior and also posterior, respectively. Dorsal way the ago side or upper side, while ventral way the frontal or lower side. These are largely used with pet anatomy, but can be provided in human anatomy as long as they are describing the side of an appendage. One instance is the dorsal fin in fish, discovered on the upper side of the fish’s body.Lateral is offered to explain anything closer come the sides of the body (toward the arms, in the traditional anatomical position), while medial is provided to describe anything towards the center of the body. In general, numerous structures the the human being body room bilateral and symmetrical with the center of the body, such together the lung or the arms.Deep describes structures closer to the interior center of the body. Because that example, skeletal in an appendage are situated deeper 보다 the muscles. Superficial is supplied to define structures that are closer to the exterior surface ar of the body. For example, the outer layers of skin are superficial to deeper great of skin.Proximal and also Distal explain one allude relative to another. Proximal refers to a suggest closer to the reference allude while distal describes a allude farther away. Once describing appendages, the proximal end of the appendage connects the appendage come the body, while the distal end is far from the body.

Diagram the anatomical terms: Directional axes in a tetrapod.


Key Takeaways

Key PointsRegional terms define the different parts that the human body by the structures and also functions of a specific region. The most basic local terms are the axial and appendicular regions.Axes usage directional state to explain the location and orientation the a specific region.The directional hatchet lateral is used to describe structures divided by a left-to-right axis.Key Termsventral: on the front next of the human body or the matching surface of an animal, typically the lower surface.posterior: Nearer the caudal finish of the body in quadrupeds or the dorsal end in bipeds.axis: A line in between two points the is provided to give direction come an anatomical region.

Regional terms in Anatomy

Regional terms explain anatomy by splitting the parts of the body into different regions that contain frameworks that are involved in comparable functions. Two primary terms are supplied to explain the key regions the the body:

The Axial an ar makes up the key axis the the person body and includes the head, neck, chest, and trunk.The Appendicular an ar makes increase the components of the person body that connect to the axial region. This contains the limbs and also appendages.

These room the two an easy categories of regional terms; however, many other terms are used to define smaller regions within the axial and also appendicular regions. Because that example, the brachial region consists that the eight as a part of the appendicular region, while the abdominal region consists the the abdomen together a smaller component of the axial region.

The abdominal region is subdivided into even smaller regions based on different functions of groups of organs and also tissues in the region. If a human being is experiencing pain in one component of the abdominal muscle region, then the smaller local divisions can help determine the organs involved in the difficulty to far better treat symptoms.

Axes describe Relative Positions

Another method for describing region An axis uses a right line between two components of the body to describe a an ar of the human body with straight direction. Because that example, blood can be claimed to flowin a proximal or distal direction v a region significant by the axis. The X, Y, and also Z axes the the Cartesian coordinate device are used explain the details location of an axis in standard anatomical position.

Many varieties of axes deserve to give regional direction. Any pair of matching directional terms have the right to be linked to kind an axis (such together proximal-distal because that an appendage).

The Dorsoventral axis (DV axis) is developed by the connection of the dorsal and also ventral points of a region. The region between the ship (ventral) and ago (dorsal) is often explained by a DV axis.The Anterioposterior axis (AP axis) is the axis created by the connection of the anterior (top) and posterior (bottom) end of a region. The AP axis the a region is by definition perpendicular come the DV axis and also vice-versa.The Left-to-right axis is the axis connecting the left and also right hand political parties of a region. The is supplied to describe the lateral political parties of a region, i m sorry in humans are regularly symmetrical approximately the center of the body. It is perpendicular come both the DV and AP axes.

Different Directional AP Axes in 3 Body segments of a Horse: Axis (A) (in red) mirrors the AP axis that the tail, (B) shows the AP axis the the neck, and also (C) reflects the AP axis that the head.


Axes give much more clarity and also detail because that describing the ar of an anatomical region. Lock are commonly used in both zoology and human anatomy, and can it is in paired v body airplane to give even an ext detail come anatomical direction, region, and also location.


Body Planes and also Sections

There are three simple reference planes offered in anatomy: the sagittal plane, the coronal plane, and also the transverse plane.


Key Takeaways

Key PointsA coronal or frontal airplane divides the body into dorsal and also ventral (back and also front, or posterior and also anterior) portions.A transverse plane, also known together an axial plane or cross-section, divides the body right into cranial and also caudal (head and also tail) portions.A sagittal aircraft divides the body right into sinister and dexter (left and right) portions.Body planes have several supplies within the anatomy field, consisting of in clinical imaging, descriptions of human body motion, and embryology.Key Termscoronal plane: any vertical plane that divides the body right into anterior and also posterior (belly and also back) sections.transverse plane: Any aircraft that divides the body right into superior and also inferior parts, roughly perpendicular to the spine.sagittal plane: any imaginary aircraft parallel to the median plane.

What room Body Planes?

Body airplane are hypothetical geometric planes used to division the body into sections. Lock are commonly used in both human and also zoological anatomy to explain the place or direction of bodily structures. Referral planes are the conventional planes used in anatomical terminology and also include:

The sagittal airplane (lateral or Y-Z plane) divides the body right into sinister and also dexter (left and also right) sides. The midsagittal (median) airplane is in the midline with the center of the body, and all other sagittal planes are parallel come it.The coronal plane (frontal or Y-X plane) divides the body right into dorsal and ventral (back and also front) portions. It additionally separates the anterior and posterior portions.The transverse aircraft (axial or X-Z plane) divides the body into superior and also inferior (head and tail) portions. It is commonly a horizontal airplane through the center of the body and also is parallel to the ground.

While these space the significant reference planes of the body, various other planes are generally used in relation to this three. A longitudinal airplane is any aircraft perpendicular come the transverse plane, when parasaggital planes room parallel to the saggital plane.The coronal plane, the sagittal plane, and also the parasaggital plane are instances of longitudinalplanes.


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Anatomical airplane in a Human: There are three simple planes in zoological anatomy: sagittal, coronal, and also transverse. A person in the anatomical position, deserve to be explained using a coordinate device with the Z-axis going native front to back, the X-axis going native left come right, and the Y-axis walking from up to down.


Applications of human body Planes

Medical imaging techniques such together sonography, CT scans, MRI scans, or pets scans are among the major applications of human body planes. By imaging a patience in typical anatomical position, a radiologist can construct an X-Y-Z axis roughly the patience to use body planes come the images. The planes can then be supplied to identify and also locate the location of the patient’s inner organs. Individual organs can likewise be split by planes to help identify smaller sized structures within the organ.

Body plane are offered to define anatomical motion in the X-Y-Z coordinate system that the body moves through. One anatomist might model a limb’s selection of motion by measuring i beg your pardon planes the limb deserve to move through and how far it is able come travel.

Anatomical readjust during embryological breakthrough is additionally described and measured v body planes. Because that example, during human embryonic breakthrough the coronal aircraft is horizontal, however becomes vertical as the embryo creates into a fetus. In to compare embryology, body planes carry out a basis for comparing the ways in i beg your pardon different varieties of organisms construct anatomically within the womb.


Key Takeaways

Key PointsThe dorsal cavity includes the major organs the the nervous system, consisting of the brain and spinal cord.The diaphragm is a paper of muscle that separates the thoracic cavity native the ab cavity.Special membrane organization surround the human body cavities, such together the meninges that the dorsal cavity and also the mesothelium of the ventral cavity.The mesothelium consists of the pleura of the lungs, the pericardium that the heart, and also the peritoneum the the abdominopelvic cavity.Key Termsabdominoplevic cavity: The ventral human body chamber that contains the abdominal muscle cavity (primarily cradle system) and the pelvic cavity (primarily reproductive system).dorsal cavity: The cavity in the back of the body that consists of the cranial and also vertebral cavities, which house the mind and spinal cord respectively.Thoracic Cavity: The ventral body chamber that includes the pericardial cavity (the heart) and the pleural cavity (the lungs).

By the broadest definition, a body cavity is any fluid-filled an are in a multicellular organism. However, the term usually describes the space where inner organs develop, situated between the skin and the external lining of the gut cavity.”The person body cavity,” generally refers come the ventral body cavity due to the fact that it is by far the biggest one in volume. Blood vessels space not taken into consideration cavities yet may be held within cavities. Many cavities carry out room because that the offal to change to transforms in the organism’s position. Castle usually includes protective membranes and sometimes bones that safeguard the organs.


Anatomical terminology because that body cavities: Humans have multiple human body cavities, including the cranial cavity, the vertebral cavity, the thoracic cavity (containing the pericardial cavity and the pleural cavity), the ab cavity, and also the pelvic cavity. In mammals, the diaphragm off the thoracic cavity native the abdominal cavity.


Dorsal

The dorsal cavity is a constant cavity located on the dorsal next of the body. It homes the guts of the upper central nervous system, consisting of the mind and the spinal cord. The meninges is a multi-layered membrane in ~ the dorsal cavity the envelops and also protects the brain and spinal cord.

Cranial

The cranial cavity is the anterior part of the dorsal cavity consisting of the an are inside the skull. This cavity has the brain, the meninges of the brain, and also cerebrospinal fluid.

Vertebral

The vertebral cavity is the posterior section of the dorsal cavity and contains the frameworks within the vertebral column. These include the spinal cord, the meninges that the spinal cord, and the fluid-filled spaces between them. This is the many narrow of all body cavities, sometimes described as threadlike.

Ventral

The ventral cavity, the interior room in the front of the body, includes many various organ systems. The organs within the ventral cavity are likewise called viscera. The ventral cavity has actually anterior and posterior portions divided by the diaphragm, a sheet of bones muscle uncovered beneath the lungs.

Thoracic

The thoracic cavity is the anterior ventral human body cavity found within the rib cage in the torso. It homes the major organs that the cardiovascular and also respiratory systems, such as the heart and lungs, but likewise includes guts from various other systems, such together the esophagus and also the thymus gland. The thoracic cavity is inside wall by two varieties of mesothelium, a kind of membrane tissue that currently the ventral cavity: the pleura lining that the lungs, and also the pericadium lining of the heart.

Abdominopelvic

The abdominoplevic cavity is the posterior ventral human body cavity discovered beneath the thoracic cavity and also diaphragm. That is generally split into the abdominal muscle and pelvic cavities. The ab cavity is not contained within bone and houses many organs that the digestive and also renal systems, and some offal of the endocrine system, such together the adrenal glands. The pelvic cavity is had within the pelvis and also houses the bladder and also reproductive system. The abdominopelvic cavity is inside wall by a kind of mesothelium referred to as the peritoneum.


Key Takeaways

Key PointsThe abdominopelvic cavity can be subdivided into 4 quadrants and nine areas.The quadrants are labeled through location: the ideal upper, right lower, left upper, and left lower quadrants.The nine regions are smaller than the 4 abdominopelvic quadrants and also include the appropriate hypochondriac, ideal lumbar, appropriate illiac, epigastric, umbilical, hypogastric (or pubic), left hypochondriac, left lumbar, and left illiac divisions.The perineum is sometimes taken into consideration to it is in the tenth division.The purpose of the abdominal muscle divisions is come describe regional anatomy in the abdomen, and to help clinicians recognize which organ and tissues are connected in a disease based ~ above which regions experience pain.Key Termsleft top quadrant: The left top quadrant is the location of the left section of the liver, the larger part of the stomach, the pancreas, left kidney, spleen, parts of the transverse and descending colon, and parts the the small intestine.Right top quadrant: The best upper quadrant includes the right part of the liver, gallbladder, ideal kidney, a small section of the stomach, parts of the ascending and transverse colon, and also parts the the little intestine.left lower quadrant: The left lower quadrant homes the majority of the tiny intestine, few of the huge intestine, the left woman reproductive organs, and also the left ureter.nine divisions: An alternating system for separating the abdominopelvic cavity right into regions.right reduced quadrant: In the right lower quadrant sit the cecum, appendix, component of the small intestines, the best female reproductive organs, and the ideal ureter.

Anatomists and medical personnel division the abdominopelvic cavity into smaller regions to facilitate study and discussion. These departments are often used come categorize the individual abdominal muscle organs by their place and duty and are used by clinicians to help diagnose the source of ab pain and determine suitable treatment. The most common divisions because that the abdominopelvic an ar are the 4 quadrants and nine regions.


Abdominal nine departments (a) and quadrant regions (b): The abdomen is subdivided into four quadrants and also nine areas.


Abdominal 4 Quadrants

The abdominopelvic region can be separated into 4 quadrants. This quadrants are characterized by the intersection the the saggital plane with the umbilical airplane (the transverse aircraft through the navel). Clinicians use these regions to recognize the organs and also tissues that may be leading to pain or uncomfortable in that region.

Right top Quadrant

The appropriate upper quadrant contains the right portion of the liver, the gallbladder, ideal kidney, a small portion of the stomach, the duodenum, the head the the pancreas, sections of the ascending and transverse colon, and parts of small intestine. Pain in this region is connected with infection and inflammation in the gallbladder and liver or peptic ulcers in the stomach.

Left top Quadrant

The left upper quadrant is the ar of the left portion of the liver, part of the stomach, the pancreas, left kidney, spleen, sections of the transverse and descending colon, and parts that the little intestine. Pain in this region is associated with malrotation of the intestine and colon.

Right reduced Quadrant

In the right reduced quadrant sit the cecum, appendix, part of the small intestines, the right fifty percent of the woman reproductive system, and the right ureter. Pain in this an ar is most commonly associated with appendicitis.

Left lower Quadrant

The left reduced quadrant houses the bulk of the little intestine, some of the big intestine, the left fifty percent of the mrs reproductive system, and the left ureter. Pains in this region is generally associated with colitis (inflammation of the huge intestine) and pelvic inflammatory disease and ovarian cysts in females.

Abdominal ripe Divisions

The nine divisions of the abdominopelvic region are smaller than the four quadrants, allowing for a more detailed discussion. These divisions are marked by two parasagittal and also two transverse planes centered roughly the navel. Most organs are part of many regions, consisting of the gallbladder, duodenum, stomach, kidneys, spleen, little intestine and colon. The perineum (the area beneath the hypogastric an ar at the bottom that the pelvic cavity) is sometimes considered to be a tenth department in this system.

Right Hypochondriac

The appropriate hypochondriac region contains the right part of the liver, the gallbladder, the right kidney, and also parts that the little intestine.

Left Hypochondriac

The left hypochondriac region contains part of the spleen, the left kidney, part of the stomach, the pancreas, and parts of the colon.

Epigastric

The epigastric (above stomach) an ar contains the majority of the stomach, part of the liver, part of the pancreas, component of the duodenum, part of the spleen, and also the adrenal glands. This region pushes out when the diaphragm contracts throughout breathing.

Right Lumbar

The ideal lumbar region consists of the gallbladder, the best kidney, component of the liver, and also the ascending colon.

Left Lumbar

The left lumbar region consists the the descending colon, the left kidney, and component of the spleen.

Umbilical

The umbilical region contains the umbilicus (navel), and also many components of the tiny intestine, such as part of the duodenum, the jejunum, and also the illeum. It additionally contains the transverse colon (the section in between the ascending and descending colons) and also the bottom parts of both the left and also right kidney.

Right Iliac

The best iliac region contains the appendix, cecum, and also the right iliac fossa. The is also commonly described as the ideal inguinal region. Pain in this area is generally connected with appendicitis.

Left Iliac

The left illiac region contains component of the descending colon, the sigmoid colon, and the appropriate illiac fossa. The is additionally commonly dubbed the left inguinal region.

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Hypogastric

The hypogastric an ar (below the stomach) has the organs approximately the pubic bone. These include bladder, part of the sigmoid colon, the anus, and also many offal of the reproductive system, such as the uterus and ovaries in females and also the prostate in males.