Anatomical Position

When an organism is in its typical anatomical position, positional descriptive terms are used to show regions and also features.

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Key Takeaways

Key PointsIn conventional anatomical position, the limbs are placed likewise to the supine position enforced on cadavers during autopsy.The anatomical place of the skull is the Frankfurt plane. In this position, the lower margins that the orbitals (eye sockets), the lower margin of the orbits, and also the top margins the the ear canals (poria) lied in the same horizontal plane.Because pets can readjust orientation with respect to their environments and appendages can readjust position with respect to the body, positional descriptive terms describe the organism only in its traditional anatomical place to avoid confusion.Key Termsappendage: A limb of the body.supine: lying on that back, reclined.anatomical position: The standard place in i m sorry the human body is standing v feet together, eight to the side, and head, eyes, and palms facing forward.

The require for Standardization

Standard anatomical position is the human body orientation supplied when explicate an organism’s anatomy. Standardization is essential to avoid confusion since most organisms can take on many different positions that may adjust the relative placement of organs. Every descriptions describe the biology in its traditional anatomical position, even when the organism’s appendages are in one more position. Thus, the typical anatomical position provides a “gold standard” as soon as comparing the anatomy of various members of the exact same species.


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Relative ar in the anatomical position: numerous terms are provided to explain relative place on the body. Cranial advert to attributes closer to the head, while caudal advert to features closer come the feet. The former of the human body is referred to as anterior or ventral, when the earlier is referred to as posterior or dorsal. Proximal and distal define relative place on the limbs. Proximal refers to a attribute that is closer come the torso, when distal refers to a function that is closer come the fingers/toes. Medial and lateral express to position relative to the midline, i beg your pardon is a upright line drawn through the center of the forehead, down v the belly switch to the floor. Medial suggests a function is closer to this line, while lateral indicates attributes further from this line.


Standard Anatomical place in Humans

The conventional anatomical place is agreed ~ above by the global medical community. In this position, a human is standing upright with the reduced limbs together or contempt apart, feet level on the floor and also facing forward, top limbs at the sides with the palms dealing with forward and also thumbs pointing away from the body, and head and eyes directed straight ahead. In addition, the arms space 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 vital implications because that directional state in those appendages.

The basis because that the conventional anatomical position in humans comes from the supine position offered for evaluating human cadavers during autopsies. Dissection of cadavers was among the major ways people learned about anatomy throughout history, i beg your pardon has tremendously influenced the ways through which anatomical expertise has occurred into the scientific field of today.


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Standard anatomical position: The areas of the body in traditional anatomical position, in which the human body is erect.


In humans, the typical anatomical position of the skull is referred to as the Frankfurt plane. In this position, the orbitales (eye sockets), lower margins the the orbits, and also the poria (ear canal upper margins) all lie in the same horizontal plane. This orientation to represent the position of the skull if the subject were was standing upright and also looking directly ahead.

It is essential to note that all anatomical descriptions are based upon the typical anatomical position unless otherwise stated.


Directional Terms

Positional state give specific descriptions that anatomical relationship and permit for consistency when referencing anatomical positions.


Learning Objectives

Identify the anatomical terms that specify the human body in space


Key Takeaways

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

Navigating Anatomy v Language

Directional state provide precise descriptions the a structure’s location. They enable a description of anatomical place by comparing ar relative to various other structures or in ~ the remainder of the body. Standard anatomical terms because that direction include:

Superior and inferior (cranial and also caudal) are used when introduce to parts of the body which are toward an end of the body. Superior frameworks are toward the head (cranial) while inferior (caudal) structures space toward the feet. Examples include the superior and also inferior vena cava, which bring deoxygenated blood far from the head (superior) and also from the reduced body (inferior) come the heart.Anterior and posterior are sometimes used in ar of superior and inferior, respectively. These words are used much more often for animal anatomy and also rarely and also only with an extremely specific an interpretation in person anatomy. Anterior refers to the side of the structure encountering up in the traditional anatomical place while posterior refers to the bottom side. For example, the pituitary gland has actually an anterior and posterior side, each of i beg your pardon secretes different species of hormones.Dorsal and also ventral are sometimes used in location of anterior and also posterior, respectively. Dorsal means the back side or top side, while ventral way the frontal or lower side. This are largely used with animal anatomy, yet can be supplied in person anatomy as lengthy as they are describing the next of an appendage. One instance is the dorsal fin in fish, discovered on the upper side that the fish’s body.Lateral is supplied to describe anything closer to the sides of the human body (toward the arms, in the typical anatomical position), while medial is used to describe anything towards the center of the body. In general, numerous structures the the human body space bilateral and also symmetrical v the middle of the body, such as the lung or the arms.Deep refers to structures closer to the interior center of the body. For example, skeleton in an appendage are located deeper 보다 the muscles. Superficial is provided to explain structures that are closer come the exterior surface of the body. Because that example, the external layers the skin room superficial come deeper great of skin.Proximal and also Distal describe one suggest relative come another. Proximal refers to a suggest closer come the reference suggest while distal refers to a point farther away. When describing appendages, the proximal finish of the appendage connects the appendage come the body, while the distal end is away from the body.

Diagram the anatomical terms: Directional axes in a tetrapod.


Key Takeaways

Key PointsRegional terms explain the different parts that the body by the structures and also functions of a details region. The most basic regional terms space the axial and also appendicular regions.Axes use directional terms to describe the location and also orientation the a specific region.The directional ax lateral is provided to describe structures split by a left-to-right axis.Key Termsventral: top top the front side of the person body or the corresponding surface of one animal, commonly the reduced surface.posterior: Nearer the caudal finish of the body in quadrupeds or the dorsal finish in bipeds.axis: A line between two points the is supplied to give direction to an anatomical region.

Regional terms in Anatomy

Regional terms describe anatomy by separating the components of the human body into different regions that contain structures that are connected in similar functions. Two main terms are provided to define the main regions of the body:

The Axial region makes up the key axis that the human body and includes the head, neck, chest, and trunk.The Appendicular region makes up the components of the human body that affix to the axial region. This has the limbs and also appendages.

These space the two straightforward categories of regional terms; however, numerous other terms are supplied to describe smaller regions within the axial and appendicular regions. Because that example, the brachial an ar consists the the arm as a component of the appendicular region, when the abdominal region consists of the abdomen together a smaller part of the axial region.

The abdominal region is subdivided into even smaller regions based on different functions of teams of organs and also tissues in that region. If a human is experiencing pain in one part of the abdominal region, then the smaller regional divisions can assist determine the organs associated in the difficulty to far better treat symptoms.

Axes define Relative Positions

Another method for describing an ar An axis uses a directly line between two components of the body to define a region of the human body with linear direction. Because that example, blood deserve to be stated to flowin a proximal or distal direction v a region marked by that axis. The X, Y, and Z axes of the Cartesian coordinate device are used define the specific location of an axis in typical anatomical position.

Many varieties of axes can give local direction. Any type of pair of corresponding directional terms can be merged 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 clues of a region. The an ar between the belly (ventral) and back (dorsal) is often explained by a DV axis.The Anterioposterior axis (AP axis) is the axis developed by the connection of the anterior (top) and also posterior (bottom) ends of a region. The AP axis of a region is by definition perpendicular to the DV axis and vice-versa.The Left-to-right axis is the axis connecting the left and right hand political parties of a region. The is used to define the lateral political parties of a region, i beg your pardon in human beings are often symmetrical roughly the center of the body. That is perpendicular come both the DV and AP axes.

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


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


Body Planes and Sections

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

What are Body Planes?

Body airplane are theoretical geometric planes offered to division the body into sections. They are generally used in both human and also zoological anatomy to explain the ar or direction of bodily structures. Reference planes space the traditional planes provided in anatomical terminology and also include:

The sagittal airplane (lateral or Y-Z plane) divides the body into sinister and also dexter (left and right) sides. The midsagittal (median) airplane is in the midline v the facility of the body, and also 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 airplane (axial or X-Z plane) divides the body into superior and also inferior (head and also tail) portions. The is generally a horizontal plane through the center of the body and also is parallel to the ground.

While these room the major reference planes of the body, other planes are frequently used in relationship to these three. A longitudinal aircraft is any aircraft perpendicular come the transverse plane, when parasaggital planes space parallel to the saggital plane.The coronal plane, the sagittal plane, and the parasaggital planes are examples of longitudinalplanes.


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Anatomical airplane in a Human: There space three simple planes in zoological anatomy: sagittal, coronal, and transverse. A human being in the anatomical position, deserve to be defined using a coordinate device with the Z-axis going from front come back, the X-axis going native left to right, and the Y-axis walk from as much as down.


Applications of human body Planes

Medical imaging approaches such as sonography, CT scans, MRI scans, or pets scans are among the primary applications of body planes. By imaging a patient in traditional anatomical position, a radiologist can build an X-Y-Z axis approximately the patience to apply 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 airplane to assist identify smaller sized structures within the organ.

Body airplane are offered to define anatomical motion in the X-Y-Z coordinate system that the human body moves through. An anatomist can model a limb’s range of activity by measuring i beg your pardon planes the limb can move through and also how much it is able to travel.

Anatomical change during embryological breakthrough is also described and also measured with body planes. Because that example, throughout human embryonic development the coronal plane is horizontal, however becomes vertical as the embryo develops into a fetus. In comparative embryology, body planes administer a basis because that comparing the ways in i beg your pardon different species of organisms construct anatomically in ~ the womb.


Key Takeaways

Key PointsThe dorsal cavity includes the primary organs the the worried system, including the brain and spinal cord.The diaphragm is a paper of muscle the separates the thoracic cavity indigenous the abdominal cavity.Special membrane tissues surround the body cavities, such together the meninges that the dorsal cavity and also the mesothelium that the ventral cavity.The mesothelium consists of the pleura that the lungs, the pericardium of the heart, and the peritoneum of the abdominopelvic cavity.Key Termsabdominoplevic cavity: The ventral body chamber that has the abdominal cavity (primarily digestive system) and the pelvic cavity (primarily reproductive system).dorsal cavity: The cavity in the back of the body that includes the cranial and vertebral cavities, which residence the brain and spinal cord respectively.Thoracic Cavity: The ventral body chamber that has the pericardial cavity (the heart) and also the pleural cavity (the lungs).

By the broadest definition, a human body cavity is any kind of fluid-filled room in a multicellular organism. However, the ax usually describes the room where inner organs develop, located between the skin and also the external lining that the gut cavity.”The person body cavity,” generally refers come the ventral human body cavity because it is by far the biggest one in volume. Blood vessels room not taken into consideration cavities however may be hosted within cavities. Most cavities carry out room because that the guts to readjust to transforms in the organism’s position. Lock usually has protective membranes and also sometimes skeletal that safeguard the organs.


Anatomical terminology for body cavities: Humans have multiple body cavities, consisting of the cranial cavity, the vertebral cavity, the thoracic cavity (containing the pericardial cavity and the pleural cavity), the abdominal cavity, and the pelvic cavity. In mammals, the diaphragm the end the thoracic cavity indigenous the abdominal muscle cavity.


Dorsal

The dorsal cavity is a continuous cavity situated on the dorsal side of the body. It residences the organs of the upper central nervous system, including the mind and the spinal cord. The meninges is a multi-layered membrane within 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 consist of of the an are inside the skull. This cavity includes the brain, the meninges that the brain, and also cerebrospinal fluid.

Vertebral

The vertebral cavity is the posterior portion of the dorsal cavity and contains the frameworks within the vertebral column. These encompass the spinal cord, the meninges of the spinal cord, and also the fluid-filled spaces in between them. This is the most narrow of every body cavities, sometimes described as threadlike.

Ventral

The ventral cavity, the interior an are in the front of the body, includes many different organ systems. The organs within the ventral cavity are additionally called viscera. The ventral cavity has actually anterior and posterior portions divided by the diaphragm, a paper of skeleton muscle discovered beneath the lungs.

Thoracic

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

Abdominopelvic

The abdominoplevic cavity is the posterior ventral body cavity found beneath the thoracic cavity and diaphragm. The is generally separated into the abdominal muscle and pelvic cavities. The abdominal muscle cavity is not consisted of within bone and houses countless organs the the digestive and also renal systems, as well as some organs of the endocrine system, such as the adrenal glands. The pelvic cavity is included within the pelvis and also houses the bladder and also reproductive system. The abdominopelvic cavity is lined by a kind of mesothelium referred to as the peritoneum.


Key Takeaways

Key PointsThe abdominopelvic cavity have the right to be subdivided into four quadrants and nine areas.The quadrants are labeled by location: the appropriate upper, best lower, left upper, and also left lower quadrants.The nine regions are smaller than the 4 abdominopelvic quadrants and also include the appropriate hypochondriac, appropriate lumbar, ideal illiac, epigastric, umbilical, hypogastric (or pubic), left hypochondriac, left lumbar, and also left illiac divisions.The perineum is sometimes thought about to be the tenth division.The purpose of the ab divisions is to describe local anatomy in the abdomen, and to aid clinicians determine which organ and also tissues are affiliated in a an illness based on which areas experience pain.Key Termsleft upper quadrant: The left top quadrant is the ar of the left section of the liver, the larger part of the stomach, the pancreas, left kidney, spleen, sections of the transverse and descending colon, and also parts the the little intestine.Right upper quadrant: The appropriate upper quadrant contains the right portion of the liver, gallbladder, appropriate kidney, a small section of the stomach, portions of the ascending and transverse colon, and also parts of the small intestine.left reduced quadrant: The left reduced quadrant dwellings the majority of the tiny intestine, few of the big intestine, the left woman reproductive organs, and also the left ureter.nine divisions: An alternative system for splitting the abdominopelvic cavity right into regions.right lower quadrant: In the right reduced quadrant sit the cecum, appendix, component of the little intestines, the ideal female reproductive organs, and also the appropriate ureter.

Anatomists and medical personnel divide the abdominopelvic cavity right into smaller regions to facilitate study and discussion. These departments are regularly used come categorize the individual abdominal muscle organs by their location and function and are supplied by clinicians to assist diagnose the resource of abdominal muscle pain and determine proper treatment. The most usual divisions because that the abdominopelvic region are the 4 quadrants and also nine regions.


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


Abdominal four Quadrants

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

Right upper Quadrant

The best upper quadrant includes the right section of the liver, the gallbladder, right kidney, a small portion of the stomach, the duodenum, the head that the pancreas, sections of the ascending and transverse colon, and parts of tiny intestine. Pain in this an ar is linked with infection and inflammation in the gallbladder and also liver or peptic ulcers in the stomach.

Left top Quadrant

The left top quadrant is the location of the left part of the liver, component of the stomach, the pancreas, left kidney, spleen, parts of the transverse and descending colon, and parts that the tiny intestine. Pains in this an ar is connected with malrotation that the intestine and colon.

Right reduced Quadrant

In the right reduced quadrant sit the cecum, appendix, component of the little intestines, the right half of the female reproductive system, and the right ureter. Pain in this region is most commonly connected with appendicitis.

Left reduced Quadrant

The left lower quadrant houses the bulk of the tiny intestine, several of the huge intestine, the left fifty percent of the female reproductive system, and also the left ureter. Pains in this region is generally linked with colitis (inflammation the the big intestine) and also pelvic inflammatory condition and ovarian cysts in females.

Abdominal nine Divisions

The nine departments of the abdominopelvic region are smaller than the four quadrants, permitting for a much more detailed discussion. These departments are marked by 2 parasagittal and also two transverse plane centered about the navel. Many organs are part of lot of regions, including the gallbladder, duodenum, stomach, kidneys, spleen, little intestine and also colon. The perineum (the area beneath the hypogastric an ar at the bottom the the pelvic cavity) is sometimes thought about to be a tenth division in this system.

Right Hypochondriac

The ideal hypochondriac an ar contains the right part of the liver, the gallbladder, the best kidney, and also parts the the little intestine.

Left Hypochondriac

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

Epigastric

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

Right Lumbar

The right lumbar an ar consists of the gallbladder, the best kidney, part of the liver, and also the ascending colon.

Left Lumbar

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

Umbilical

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

Right Iliac

The right iliac an ar contains the appendix, cecum, and the best iliac fossa. That is likewise commonly described as the right inguinal region. Pain in this area is generally linked with appendicitis.

Left Iliac

The left illiac an ar contains part of the diminish colon, the sigmoid colon, and the ideal illiac fossa. The is also commonly dubbed the left inguinal region.

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Hypogastric

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