BODY ORIENTATION
O U T L I N E
13.1 A Regional Approach to Surface Anatomy
13.2 Head Region 398
13.2a Cranium 399
13.2b Face 399
13.3 Neck Region 399
398
13
13.4 Trunk Region 401
13.4a Thorax 401
13.4b Abdominopelvic Region
13.4c Back 404
403
Surface
13.5 Shoulder and Upper Limb Region
13.5a
13.5b
13.5c
Shoulder 405
Axilla 405
Arm 405
405
Anatomy
13.5d Forearm 406
13.5e Hand 406
13.6 Lower Limb Region 408
13.6a Gluteal Region 408
13.6b Thigh 408
13.6c Leg 409
13.6d Foot 411
MODULE 1: BODY ORIENTATION
,398 Chapter Thirteen Surface Anatomy
magine this scenario: An unconscious patient has been brought Health-care professionals rely on four techniques when
I to the emergency room. Although the patient cannot tell the ER
physician what is wrong or “where it hurts,” the doctor can assess
examining surface anatomy. Using visual inspection, they directly
observe the structure and markings of surface features. Through
some of the injuries by observing surface anatomy, including: palpation (pal-pā ś hŭ n) (feeling with firm pressure or perceivin
by the sense of touch), they precisely locate and identify anatomi
■ Locating pulse points to determine the patient’s heart rate and
features under the skin. Using percussion (per-ku s̆ h ú n̆ ), they tap
pulse strength
firmly on specific body sites to detect resonating vibrations. And
■ Palpating the bones under the skin to determine if a
via auscultation (aws-ku ̆l-tā ś hu n̆ ), they listen to sounds emitted
fracture has occurred
from organs.
■ Passively moving the limbs to observe potential damage to
In our discussion of surface anatomy in this chapter, th
muscles and tendons
illustrations include some structures that we have discussed previ
■ Examining skeletal and muscular landmarks to discover
ously and other features yet to be discussed. We strongly sugges
whether joints are dislocated
that you return to this chapter often as you explore and examin
Examination of surface anatomy must often substitute for other body systems in subsequent chapters. In addition, before you
interviewing the patient, and when the health-care professional is a begin, refer back to chapter 1 and review the discussion of body
keen observer, it may be very accurate in assessing illness or injury. region names and abdominopelvic regions and quadrants.
13.1 A Regional Approach Study Tip!
to Surface Anatomy When preparing for an anatomy exam, your best study aid is your
Learning Objectives: own body. Palpating surface anatomy features on yourself will help
1. Explain the importance of surface anatomy in learning you recall these features on an exam and, more importantly, give you
about internal structures. a richer understanding of human anatomy.
2. Discuss how surface anatomy studies help us diagnose and
treat disease.
Surface anatomy is a branch of gross anatomy that exam-
ines shapes and markings on the surface of the body as they 13.2 Head Region
relate to deeper structures. An understanding of surface anatomy
Learning Objective:
is essential for locating and identifying anatomic structures prior
1. Identify the surface features of the cranial and facial regions.
to studying internal gross anatomy. Health-care personnel use
surface anatomy to help diagnose medical conditions and to treat The head is the most complex and highly integrated region
patients, as when taking a pulse, inserting a needle or tube, or of the body because it houses the brain, which communicate
performing physical therapy. You have already begun your study with and controls all of the body systems. The head is structur
of surface anatomy; each time we have asked you to palpate a ally and developmentally divided into the cranium and the face
part of your body and feel for a structure, you have examined Figure 13.1 shows the regions and many of the surface anatomy
your own surface anatomy. structures of the head and neck.
Frontal region
Superciliary arch
Frontal (with eyebrow)
Cranial Temporal Bridge of
Superior palpebra nose
Occipital
Auricular Auricle Dorsum nas
Orbital External acoustic meatus Apex of nos
Zygomatic arch Ala nasi
Nasal Nostril
Buccal region Lips (labia)
Facial
Oral Inferior palpebra Mental
Philtrum region
Buccal
Thyroid
Mental cartilage
Neck (cervical) Sternoclavicular joint of larynx
Thyroid cartilage
Nuchal of larynx Clavicle
(posterior
neck) Suprasternal
notch
(a) Lateral view (b) Anterior view
Figure 13.1
Head and Neck. The major regions of the head and neck are shown in (a) lateral view, while specific features are shown in (b) anterior view.
, Chapter Thirteen Surface Anatomy
13.2a Cranium
The cranium (also called the cranial region or braincase) is cov- CLINICAL VIEW
ered by the scalp, which is composed of skin and subcutaneous
tissue. The cranium can be subdivided into three regions, each Lip Color as a Diagnostic To
having prominent surface anatomy features.
Lip color is the collective result of a combination of pigme
The frontal region of the cranium is the forehead.
that contribute to a person’s skin color, most notably mela
Covering this region is the frontal belly of the occipitofronta-
hemoglobin, and carotene.
lis muscle. The frontal region terminates at the superciliary
arches. You can feel these bony elevations immediately inferior The pigment melanin has two subtypes: Eumelanin is black,
to your eyebrows. pheomelanin is typically slightly yellow in low concentrations
Laterally, the scalp covers the sides of the skull in each tem- slightly reddish in high concentrations. The ratio of these ty
poral region and terminates just superior to the ear. The tempora- of melanin determines the skin and lip color. Hemoglobin
lis muscle is attached at the temporal region, and is easily palpable oxygen-binding protein in red blood cells, contributes a red or
when the jaw is repeatedly clenched. Running over the temporalis hue. Carotene, a yellow-orange pigment found in carrots, sw
muscle is the superficial temporal artery. You can feel the pulse potatoes, and squash, contributes those hues to the skin and
of this artery just posterior to the orbits and anterior to the auricle
Variations in lip color result from the combinations and amount
of your ear.
these pigments. However, lip color is also affected by our envi
The posterior part of the cranium is the occipital (ok-sip ́ i-ta ̆l)
ment and state of health. For example, cold weather causes our
region. In the center of that region is the external occipital protu-
to appear “blue” because blood (and its reddish-colored hemoglo
berance, a rounded or pointed projection (see figures 7.5, 7.8). In
is being shunted away from the superficial lips and toward de
chapter 7, you learned that males tend to have a more prominent,
body structures in order to conserve heat. Low body tempera
pointed external occipital protuberance than females. Palpate your
for other reasons, as well as several health conditions, also ca
own external occipital protuberance. Is it small and rounded, or
“blue lips.” For instance, a patient who has anemia, pneumo
somewhat larger and pointed?
emphysema, or certain disorders of the cardiovascular system c
exhibit blueness or discoloration of the lips.
W H AT D O Y O U T H I N K ?
●
1 Can you name some other facial muscles not already mentioned in
this chapter that can be palpated easily under the skin?
when the mouth is open. Look in the mirror and observe t
13.2b Face cal depression between your nose and upper lip; this is ca
The face is divided into five regions: auricular, orbital, nasal, oral, philtrum (fil t́ ru m
̆ ; philtron = a love charm).
and mental. The buccal (bu ̆k ́al) region refers to the cheek. Wit
The auricular (aw-rik ū́ -la r̆ ; auris = ear) region is composed region is the buccinator muscle. Palpate the superolateral r
of the visible surface structures of the ear as well as the ear’s your cheek and locate your zygomatic bone and the zygoma
internal organs, which function in hearing and maintaining equi- Finally, continuing in the inferior direction, look in
librium. The auricle (aw ŕ i-kl), or pinna, is the fleshy part of the ror and observe the mental region, which contains the men
external ear. Within the auricle is a tubular opening called the chin. Usually, the mentum tends to be pointed and almost tr
external acoustic meatus. The mastoid process is posterior and in females, while males tend to have a “squared-off” mentum
inferior to the auricle. Palpate your mastoid process; it should feel
like a bony bump immediately posteroinferior to the ear. W H AT D I D Y O U L E A R N?
The orbital (or ocular) region includes the eyes and
associated structures. Most orbital region surface features pro- ●
1 Identify at least two surface features of the orbital region
protect the eye.
tect the eye. Eyebrows protect against sunlight and potential
mechanical damage to the eyes; eyelids (palpebrae; pal ṕ ē-brē) ●
2 Identify the narrow, bony, superior part of the nasal region
close reflexively to protect against objects moving near the eye; between the eyes.
and eyelashes prevent airborne particles from contacting the
eyeball. The superior palpebral fissure, or upper eyelid crease,
is palpated easily on most individuals, although Asians do not 13.3 Neck Region
have a superior palpebral fissure. Learning Objectives:
The nasal region contains the nose. The firm, narrow part of
1. Outline the palpable structures in the regions of the
the nose that projects anteriorly between the eyes is the bridge; it is
2. Name the triangles of the neck, and identify the stru
formed by the union of the nasal bones. Anteroinferior to the bridge
they contain.
is the fleshy part of the nose, called the dorsum nasi (nā ź ē; nasus =
nose). Farther anteroinferiorly is the tip of the nose, called the apex. The neck, also called the cervical region or cervix (s
The nostrils, or external nares (nā ŕ es; sing., naris, na ŕ is), are the is a complex region that connects the head to the trunk.
paired openings into the nose. The ala nasi (wing of the nose) forms nal cord, nerves, trachea, esophagus, and major vessels
the flared posterolateral margin of each nostril. this highly flexible area. In addition, the neck contains the
The oral region is inferior to the nasal region; it includes (voice box) and several important glands. For purposes
the buccal (cheek) region, the fleshy upper and lower lips (labia), cussion, the neck can be subdivided into anterior, poster
and the structures of the oral cavity (mouth) that can be observed lateral regions.
