Erin Odya teaches Anatomy & Physiology at Carmel High School in Carmel, Indiana, one of Indiana's top schools. She is also the author of Anatomy & Physiology For Dummies.
Pat DuPree taught anatomy/physiology, biology, medical terminology, and environmental science.
The Language of Anatomy & Physiology
IN THIS CHAPTER
Learning to speak the language
Casing the cavities
Orienting yourself to the body
Human anatomy is the study of our bodies' structures while physiology is how they work. It makes sense, then, to learn the two in tandem. But before we can dive in to the body systems and their intricate structures, you must first learn to speak the language of the science.
Organization of the Body
As you know, the body is organized into systems, grouping together the organs that work together to achieve a common goal. To house all these organs, our body must create spaces to hold them. The body has two cavities that achieve this: the dorsal cavity, which holds the brain and spinal cord and the ventral cavity that holds everything else. The dorsal cavity splits into the spinal cavity, which holds the spinal cord, and the cranial cavity that houses the brain. The ventral cavity is split into the thoracic cavity and the abdominopelvic cavity by a large band of muscle called the diaphragm. Within the thoracic cavity are the right and left pleural cavities, which hold each lung, and the mediastinum. Within the mediastinum is the pericardial cavity which contains the heart. The abdominopelvic cavity divides into the abdominal cavity (with the stomach, liver, and intestines) and the pelvic cavity (with the bladder and reproductive organs), though there's no distinct barrier between the two.
In order to create these cavities within our bodies, we have membranes to border the space. The visceral membrane lies atop of the organs, making direct contact with them. For example, the outermost layer of the heart is called the visceral pericardium and on the lungs it's the visceral pleura. The parietal membrane lies on the other side of the spaces or lining the cavity itself. So the lining of the abdominopelvic cavity is known as the parietal peritoneum (note that it's not the parietal abdominopelvic that just sounds weird).
The other parts of the body are divided into axial and appendicular areas. The axial portions are the parts of your body that form your axis - the head, chest, and abdomen. The appendicular portions form your appendages - your arms and legs. For consistency when referencing them, there are proper terms for all of the body's areas. The terminology used in identifying many of the regions is found in Table 1-1. You'll notice these terms popping up all over this book.
Table 1-1 The Body's Regions
sole/bottom of foot
back of knee
That's a lot of new terms for the first chapter! Let's see how well they're sticking.
Q. Which of the following organs would you find in the mediastinum?
- I only
- II only
- III only
- I & II
- I, II, & III
A. The correct answer is only the heart. The mediastinum is defined as the area between the lungs and the liver is in the abdominopelvic cavity.
1-10 Label the body cavities illustrated in Figure 1-1.
Illustration by Kathryn Born, MA
FIGURE 1-1: Body cavities.
11-16 Match the description to identify the membranes that create the body's cavities.
a. parietal pericardium
b. parietal peritoneum
c. parietal pleura
d. visceral pericardium
e. visceral peritoneum
f. visceral pleura
- _____ The outermost layer encasing the heart
- _____ The membrane that lies on the surface of the liver
- _____ The surface of the heart
- _____ The lining of the thoracic cavity
- _____ The membrane making direct contact with the lungs
- _____ The layer that lines the abdominopelvic cavity
17 True or False: The cephalic region is considered part of the appendicular body.
18 Which body part would be affected if you injured your tarsal region?
19 If you suffered a laceration (cut) to your chin, the injury would be located in the ____ region.
20 Identify the correct pairing of terms:
- popliteal - inner elbow
- lumbar - back of the neck
- antecubital - upper arm
- coxal - shoulder
- sural - back of lower leg
Getting into Position
In anatomy and physiology, we often identify the body's features in reference to other body parts. Because of this, we need a standardized point of reference, which is known as anatomical position.
Anatomical position is the body facing forward, feet pointed straight ahead, arms resting on the sides, with the palms turned outward. Unless you are told otherwise, this is the body's position whenever specific body parts are described in reference to other locations.
Because we can only see the external surface of the body, sections must be made in order for us to see what's inside. It's important to take note of what type of section was made to provide the view you see in a picture or diagram. There are three planes (directions) in which sections can be made:
- frontal: separating the front from the back
- sagittal: dividing right and left sides
- transverse: creating top and bottom pieces
We also use directional terms to describe the location of structures. It helps to learn them as their opposing pairs to minimize confusion. The most commonly used terms are:
- anterior/posterior: in front of/behind
- superior/inferior: above/below
- medial/lateral: closer to/further from the midline (also used with rotation)
- superficial/deep: closer to/further from the body surface
- proximal/distal: closer to/further from attachment point (used for appendages)
Right and left are also used quite often but be careful! They refer to the patient's right and left, not yours.
You got it? Let's find out.
21-23 Identify the planes of body sections in Figure 1-2.
Illustration by Kathryn Born, MA
FIGURE 1-2: The body's planes.
24-28 Fill in the blanks.
- The neck is __________ to the hips.
- The lungs are __________ to the rib cage.
- The nose is __________ to the ears.
- The wrist is __________ to the shoulder.
- The buttocks are __________ to the navel (belly button).
Answers to Questions on Terminology
The following are answers to the practice questions presented in this chapter.
1-10 Figure 1-1 should be labeled as follows:
1. j. ventral, 2. d. dorsal, 3....