2.1: Lab Exercise 1- The Language of Anatomy

Lab Summary: In this lab, you will practice using anatomical terminology, identifying body regions, planes, cavities, and serous membranes. This exercise will help you learn the “ABCs” of A&P, which uses a language all its own! The information in this lab is also applicable to your lecture course for chapter 1. You will use this information throughout your study of A&P and classes involving human bodies. For example, if you know the location of the axillary region, you will know where an axillary temperature is taken. In another example, if you know the definition and application for the term proximal, you will know that a proximal fracture (break) in the femur is closer to the hip than the knee.

Your objectives for this lab are:

• Describe the anatomical position, and explain its importance when using anatomical terminology

• Use proper anatomical terminology to describe

  • body regions and the location of these regions to each other (ex. The otic regions are posterior and lateral to the tip of the nose)
  • orientation and direction (anterior/ventral, posterior/dorsal, medial lateral, proximal, distal, inferior/caudal, superior/cranial, superficial, deep)
  • body planes (sagittal, transverse, frontal/coronal)

• Name the body cavities and indicate the important organs in each. Cavities to concentrate on are

  • Dorsal, cranial, and vertebral
  • Ventral, thoracic, abdominal, pelvic, pleural, pericardial
• Describe the serous membranes of the ventral body cavities,
  • Location of visceral vs parietal membranes
  • Pleural, pericardial, and peritoneal membranes

Background

Anatomical Language

Anatomists and health care providers use terminology to precisely talk about the anatomy of the human body that can seem overwhelming at first. The purpose of this language is not to confuse, but rather to increase precision, efficiency, and to reduce medical errors. For example, if you tell a friend that you have a scar “above the wrist” is it located on the forearm two or three inches away from the hand? Or is it at the base of the hand? Is it on the palm-side or back-side? By using precise anatomical terminology, including anatomical position, regional terms, directional terms, body planes, and body cavities, we can eliminate ambiguity and increase precision.

Anatomical terms are made up of roots, prefixes, and suffixes. The root of a term often refers to an organ, tissue, or condition, whereas the prefix or suffix often describes the root. For example, in the disorder hypertension, the prefix “hyper-” means “high” or “over,” and the root word “tension” refers to pressure, so the word “hypertension” refers to abnormally high blood pressure.

Anatomical Position

Anatomists have standardized the position of the body when it is referenced using descriptive terms to increase precision in language. Just as maps are normally oriented with north at the top, the standard body “map,” called anatomical position, is that of the body standing upright, with the feet at shoulder width and parallel, toes forward. The upper limbs are held out to each side, and the palms of the hands face forward (see Figures 1.3 or 1.4 for an example). Using this standard position helps reduce confusion and increase precision while describing parts of the human body. It does not matter how the body being described is oriented (ex: a doctor describing their patient who is sitting on an exam table), the terms are used as if that person is in anatomical position. For example, a scar in the “anterior (front) carpal (wrist) region” would always be present on the palm side of the wrist. The term “anterior” would always be used even if the hand were palm down on a table.

A body that is lying down is described as either prone or supine. Prone describes a face-down orientation, and supine describes a face up orientation. These terms are sometimes used in describing the position of the body during specific physical examinations or surgical procedures and you may hear the terms used to describe the position of the cadavers used in this course.

Activity 1.1: Learning Regional Terms

The human body’s numerous regions have specific terms to help increase precision in language (see Figure \(\PageIndex{1}\)). Notice that the term “brachium” or “arm” is reserved for the “upper arm” and “antebrachium” or “forearm” is used rather than “lower arm.” Similarly, “femur” for “thigh” is correct, and “leg” or “crus” is reserved for the portion of the lower limb between the knee and the ankle.

Figure \(\PageIndex{1}\): Regions of the Human Body. The human body is shown in anatomical position in an (a) anterior view and a (b) posterior view. The regions of the body are labeled in boldface.

In the next activities, you will answer questions using the terms you learned in this activity.

Activity 1.2: Applying Directional Terms

Anatomists use a standard group of terms to describe directions concerning the human body (Figure \(\PageIndex{2}\)). Do remember that these terms are relative! These terms are essential for describing the relative locations of different body structures. For instance, an anatomist might describe one band of tissue as “inferior to” another or a physician might describe a tumor as “superficial to” a deeper body structure. Learning these terms now is critical to avoid confusion when you are studying or describing the locations of particular body parts in this course and in any future study of the human body.

• Anterior (or ventral) - Describes the front or direction toward the front of the body. For example, the toes are found on the anterior portion of the foot.
• Posterior (or dorsal) - Describes the back or direction toward the back of the body. For example, the spinal column is posterior to the sternum.
• Superior (or cranial) - Describes a position above or higher than another part of the body. For example, the eyes are superior to the mouth. Superior and cranial can often be used interchangeably though cranial is used to specifically refer to a structure near or toward the head. In quadrupeds the terms sometimes cannot be used interchangeably.
• Inferior (or caudal) - Describes a position below or lower than another part of the body. For example, the pelvis is inferior to the abdomen. Inferior and caudal can often be used interchangeably though caudal is used to specifically refer to a structure near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). In quadrupeds the terms sometimes cannot be used interchangeably.
• Lateral - Describes the side or direction toward the side of the body. For example, the thumb is lateral to the other digits.
• Medial - Describes the middle or direction toward the middle of the body. For example, the big toe is the most medial toe.
• Proximal - Describes a position in a limb that is nearer to the point of attachment or the trunk of the body. For example, the upper arm is proximal to the wrist.
• Distal - Describes a position in a limb that is farther from the point of attachment or the trunk of the body. For example, the foot is distal to the thigh.
• Superficial - Describes a position closer to the surface of the body. For example, the skin is superficial to the bones.
• Deep - Describes a position farther from the surface of the body. For example, the brain is deep to the skull.
• Contralateral - Describes structures found on opposite sides of the body (right vs. left side). For example, the right foot is contralateral to the left arm.
• Ipsilateral - Describes structures found on the same side of the body. For example, the right hand and right shoulder are ipsilateral.

Figure \(\PageIndex{2a}\): Directional Terms Applied to the Human Body. Paired directional terms are shown as applied to the human body in anatomical position.

Figure \(\PageIndex{2b}\): Cross section of the thigh showing superficial and deep terms

Procedure for Activity 1.2: Applying Directional Terms

Part 1 Procedure: Anatomical Position
Using the definition of anatomical position (found in the background information) and proper anatomical language, take turns with your lab partner to give simple, one-movement verbal instructions to transition from the given starting positions (listed in the table below), so that the other person ends up in anatomical position. Write your detailed step-by-step instructions in the provided table. 

Starting Position	Instructions Given to Move to Anatomical Position
Example: From a glamor shot with the feet and torso facing away from you and the chin angled over the left shoulder toward you.	Example: Rotate the mental (chin) region anteriorly and medially Turn the entire body 180 degrees Face palmar (palm) region anteriorly
1: From lying face-up on the ground with their head, back, hands, and feet on the floor with both knees bent
2: From a seated position on the floor with their legs straight and arms folded across their chest
3: From sitting in a chair with their back to you and hands sitting in their lap
4: From standing and facing you with their legs crossed and hands in their pocket

Part 2 Procedure: Labeling Anatomical and Regional Terminology

1. Obtain tape and paper (or sticky notes) and two of the following models (a torso model, mini muscle person torso, skeleton)
2. Write the following terms on paper or sticky notes and attach them to your models. It’s up to you on which models you correctly place your labels.
   • Directional terms: Superior, lateral, caudal, proximal, superficial, dorsal
   • Regional terms: axillary, brachial, femoral, coxal, cephalic, olecranal, popliteal, antecubital, acromial, ocular, thoracic
3. Once you are done, have another group check your accuracy and make any necessary corrections.
4. Then, have your instructor or TA check your accuracy.

Part 3 Procedure: Applying Anatomical and Regional Terminology
Use appropriate anatomical and regional terminology to fill in the blanks in the questions below.

1. The eyes are _______________________________, _________________________, and _______________________________ to the tip of the nose.
2. The antecubital region is _________________________to the olecranal region.
3. The bones are _____________________ to the muscles that move them.
4. The patellar region is _______________________ to the tarsal region.
5. The sternal region is ________________________ to the mamillary regions.
6. The most distal region of the leg is the ____________________________ region.
7. The umbilical region is _________________________ to the mental region.
8. The most superficial organ of the human body is the _____________________.
9. The crease that forms when you flex (bend) your leg at the hip is called the _____________________ region.
10. When you clap, the two regions of the hand that meet to make sound are the ___________________ regions.

Activity 1.3: Learning Body Sections & Planes

Body Planes

A section is a two-dimensional surface of a three-dimensional structure that has been cut. Modern medical imaging devices enable clinicians to obtain “virtual sections” of living bodies which we call these scans. Body sections and scans can be correctly interpreted, however, only if the viewer understands the plane along which the section was made. A plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine (Figure \(\PageIndex{3}\)).

• Sagittal plane - Divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane.
• Frontal plane - Divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is sometimes referred to as a coronal plane.
• Transverse plane - Divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.

Figure \(\PageIndex{3}\): Planes of the Body. The three planes most commonly used in anatomical and medical imaging are the sagittal, frontal, and transverse planes.

Body Cavities and Associated Serous Membranes

The body maintains its internal organization by means of membranes, sheaths, and other structures that separate compartments. The dorsal (posterior) cavity and the ventral (anterior) cavity are the largest body compartments (Figure \(\PageIndex{4}\)). These cavities contain delicate internal organs, and the ventral cavity allows for significant changes in the size and shape of the organs as they perform their functions. The lungs, heart, stomach, and intestines, for example, can change their shape considerably during expansion or contraction without distorting other tissues or disrupting the activity of nearby organs since they are found in cavities.

Figure \(\PageIndex{4}\): Dorsal and Ventral Body Cavities. The ventral cavity includes the thoracic and abdominopelvic cavities and their subdivisions. The dorsal cavity includes the cranial and spinal cavities.

The dorsal and ventral cavities are each subdivided into smaller cavities (Figure \(\PageIndex{4}\)). In the dorsal cavity, the cranial cavity houses the brain, and the vertebral (spinal) cavity encloses the spinal cord. Just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The brain and spinal cord are protected by the bones of the skull and vertebral column and by cerebrospinal fluid, a colorless fluid produced by the brain, which cushions the brain and spinal cord within the dorsal cavity.

The ventral cavity has two main subdivisions: the thoracic cavity and the abdominopelvic cavity. The thoracic cavity is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. The thoracic cavity contains the lungs (each found in a pleural cavity and surrounded by pleural membranes) and the heart (found in a pericardial cavity and surrounded by pericardial membranes). Many organs in the ventral cavity have both a visceral serous membrane and a parietal serous membrane. The visceral membrane lies directly on the organ; the parietal membrane is more superficial, and, thus, closer to the external body wall. Between the two membranes is a thin, lubricating fluid. The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity. The abdominopelvic cavity, containing the peritoneal membranes, is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that primarily houses the digestive organs, and the pelvic cavity, the division that primarily houses the organs of reproduction.

Procedure for Activity 1.3: Learning Body Sections & Planes

1. Obtain a large torso model.
2. Using the information in Activity 1.3 and the torso model, fill in the table below. If there is more than one organ in a cavity, list at least two organs.
3. Then, answer the multiple-choice questions below.

Body cavity	Organ Example(s)
Cranial
Abdominal
Pericardial
Pleural
Ventral

For each of the following questions there could be one or more than one correct answer.

1. Choose the body plane(s) that would allow you to see both lungs at the same time:

A) Midsagittal

B) Parasagittal

C) Frontal

D) Transverse

E) Oblique

2. Choose all possible body plane(s) that would allow you to see the brain and the spinal cord:

A) Sagittal

B) Frontal

C) Transverse

D) Oblique

3. Choose the body plane(s) that would allow you to see the brain but not the spinal cord:

A) Midsagittal

B) Parasagittal

C) Frontal

D) Transverse

E) Oblique

4. Choose the body plane(s) that would allow you to see the right eye but not the left eye:

A) Midsagittal

B) Parasagittal

C) Frontal

D) Transverse

E) Oblique

 5. The serous membrane around the heart that sits directly on the heart itself is called _________.

A)  visceral pleura

B)  visceral pericardium

C)  visceral peritoneum

D)  parietal pericardium

E)  parietalpleura

Additional Learning Resources:

• Watch these two (2) videos to learn more about these critical, introductory concepts of A&P listed above
  • https://www.youtube.com/watch?v=D4vayAF4atI&feature=youtu.be
  • https://www.youtube.com/watch?v=4UJ4sylQsEM&feature=youtu.be

• Practice anatomical terminology and labeling of regions, cavities, and membranes here:

  • https://wps.pearsoned.com/bc_marieb_hap_9_oa/218/55856/14299219.cw/index.html (choo se chapter 1)
  • https://wps.pearsoned.com/bc_martini_fap_8_oa/93/23992/6141952.cw/index.html (choose chapter 1)
  • http://academic.pgcc.edu/~aimholtz/AandP/PracPrac/2050_Lab1/Lab1_Terminology.html (Terminology)
  • http://academic.pgcc.edu/~aimholtz/AandP/PracPrac/2050_Lab2/Lab2_RegionsAndCavities.html (regions and cavities)
  • https://webanatomy.umn.edu/ch1-topics (regions and cavities)