Anatomy Chapter 13 Surface Anatomy

Surface Anatomy

A branch of gross anatomy that examines shapes and markings on the surface of the body as they relate to deeper structures. Healthcare personnel use surface anatomy to help diagnose medical conditions and to treat patients, as when taking a pulse, inserting a need or tube, or performing physical therapy.

Neck Region

Also called cervical region Complex region that connects the head to the trunk The spinal cord, nerves trachea, esophagus, and major vessels traverse this highly flexible area. Also contains the larynx (voice box) and several important glands. Subdivided into anterior, posterior, and lateral regions.

Axilla

"Armpit" Clinically important because of the nerves, axillary blood vessels, and lymph nodes located there. Pectoralis major: forms the fleshy anterior axillary fold, which acts as the anterior border of the axilla. Latissimus dorsi and Teres major: form posterior axillary fold. Axillary lymph nodes: may become tender and swollen due to an infection, or they may become hard if breast cancer cells spread to them. The Axillary artery pulse can be palpated.

Arm Region (Anterior)

"brachium" Extends from the shoulder to the elbow. Anterior side: Cephalic vein is evident in muscular individuals. Found along the anterolateral border of the entire upper limb. It terminates in a small depression, bordered by the deltoid and pectoralis major, called the clavipectoral triangle. Basilic vein is sometimes evident on the medial side. Brachial artery is located on the medial side, pulse can be palpated. This region is clinically important in measuring blood pressure. Biceps brachii: prominent when elbow is flexed Anterior surface of the elbow: Cubital fossa is the depression within which the median cubital vein connects the basilic and cephalic veins. Common site for venipuncture.

Posterior Region of the Neck

(nuchal region) Houses the spinal cord, cervical vertebrae, and associated structures. Can palpate the spinous process of the vertebra prominens (C7). Ligamentum nuchae: A thick ligament that extends from C7 to the nuchal lines of the skull.

Four techniques are used when examining surface anatomy

- Visual Inspection -Palpation (feeling and identifying structures under the skin with firm pressure or sense of touch) -Percussion (detecting resonating vibrations by tapping) -Auscultation (listen to sounds emitted from organs)

Supraclavicular Triangle

Bounded by the clavicle, omohyoid, and sternocleidomastoid muscles. Its contains part of the subclavian vein and artery as well as some lymph nodes.

Carotid Triangle

Bounded by the sternocleidomastoid, omohyoid, and posterior digastric muscles. If palpated, can feel the pulse of the common carotid artery. Also contains internal jugular vein and some cervical lymph nodes.

Anterior Region of the Neck

Can palpate the larynx, trachea, and the sternal notch. Larynx: (voice box) found in the middle of the anterior neck, composed of multiple cartilages. Its largest is the thyroid cartilage. In males, the larynx has a noticeably pointed laryngeal prominence (Adam's apple). Trachea (air tube) and cricoid cartilage: inferior to the larynx Suprasternal notch: Where the neck terminates at. Located on the manubrium and the left and right clavicles.

Auricular Region

Composed of the visible surface structures of the ear as well as the ear's internal organs. Auricle (pinna) is the fleshy part of the external ear. Within the auricle is a tubular opening called the external acoustic meatus. The mastoid process is posterior and inferior to the auricle.

Mental Region

Contains the mentum, or chin. Tends to be pointed and almost triangular in females and squared off in males.

Left and Right Lateral Regions of the Neck

Contains the sternocleidomastoid muscles. Each sternocleidomastoid muscle partitions each side of the neck into two clinically important triangles, an anterior triangle and a posterior triangle. Each of these triangles houses important structures that extend through the neck, and these triangles are further subdivided into smaller triangles.

Cranium

Covered by the scalp. Three regions: Frontal, Temporal, and occipital region.

Face

Divided into five regions: Auricular, orbital, nasal, oral, and mental.

Thigh Region

Extends between the hip and the knee on each lower limb. Important element of thigh surface anatomy is a region called the femoral triangle. A depression inferior to the inguinal ligament and on the anteromedial surface in the superior portion of the thigh. It is bounded superiorly by the inguinal ligament, laterally by the sartorius muscle, and medially by the adductor longus muscle. The femoral artery, vein, and nerve travel through this region, making it an important arterial pressure point for controlling lower limb hemorrhage. Distal anterior region: quadriceps femoris. Four skeletal features: Greater trochanter on lateral thigh, patella, lateral and medial epicondyles of both the femur and tibia. Lateral side of thigh, tendinous iliotibial tract. Posterior side of thigh: tendinous attachments of the hamstring muscles. Popliteal fossa- behind knee

Hand Region

Flexion creases, fingerprints, and fingernails. Anteriorly, flexion creases are seen for the metacarpophalangeal (MP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints. Thenar eminence is the thickened, muscular region of the hand that forms the base of the palm immediately proximal to the little finger. The tendons extend to each of the fingers from the extensor digitorum muscle are readily observed on the posterior side of the hand, the MP joints (knuckles) are formed by the distal ends of metacarpal bones II-V.

Frontal region

Forehead Frontal belly of the occipitofrontalis muscle covers this region. Terminates at the superciliary arches.

Arm Region (Posterior)

Formed by the triceps brachii. Three boney prominences are readily identified in the distal region of the brachium near the elbow: Lateral epicondyle of the humerus Olecranon Medial epicondyle of the humerus Ulnar Nerve: transverses posterior and inferior to the medical epicondyle. When we hit our funny bone, this is what we are affecting.

Oral Region

Includes buccal (cheek) region, the fleshy upper and lower lips (labia), and the structures of the oral cavity (mouth) that can be observed when the mouth is open. Philtrum: The vertical depression between your nose and upper lip.

Orbital Region

Includes the eyes and associated structures. Most features protect the eye Eyebrows: protect against sunlight and potential mechanical damage to the eyes. Eyelids (palpebrae): Close reflexively to protect against objects moving near the eye Eyelashes: Prevent airborne particles from contacting the eyeball. Superior palpebral fissure: upper eyelid crease

Submandibular Triangle

Inferior to the mandible and posterolateral to the submental triangle. Bounded by the mandible and the bellies of the digastric muscle. Submandibular gland, which can be palpated. Its a bulge inferior to the mandible

Leg Region

Knee to foot Anterior: Tibial tuberosity immediately inferior to the knee joint. Anterior border of the tibia (shin). Distal end: medial malleolus and lateral malleolus along the sides of the ankle Posterior: calcaneal tendon along the posteroinferior leg. The pulse of the posterior tibial artery can be palpated. Located in the posterioinferior to the medial malleolus. Lateral: head of fibula, lateral malleolus, small saphenous vein can be seen along the lateral malleolus. Superficial vein of the leg is the great saphenous vein, seen subcutaneously on the medial side of the leg.

Anterior Triangle

Lies anterior to the sternocleidomastoid muscle and inferior to the mandible. Subdivided into four smaller triangles: Submental, submandibular, carotid, and muscular triangles.

Head Region

Most complex and highly integrated region of the body because it houses the brain, which communicates with and controls all of the body systems. Structurally and developmentally divided into the cranium and the face.

Muscular Triangle

Most inferior of the four triangles. Contains the sternohyoid and sternothyroid muscles, as well as the lateral edges of the larynx and the thyroid gland. Also cervical lymph nodes.

Submental Triangle

Most superiorly placed of the four triangles. Posterioinferior to the chin in the midline of the neck and partially bounded by the anterior belly of the digastric muscle. Contains some cervical lymph nodes and tiny veins. These lymph nodes may enlarge is you are ill.

Nasal Region

Nose Bridge: firm, narrow part of the nose that projects anteriorly between eyes. It is formed by the union of the nasal bones. Dorsum nasi: Anterioinferior to the bridge is the fleshy part of the nose. Apex: farther anterioinferiorly is the tip of the nose. Nostrils (external flares): the paired openings into the nose. Ala nasi: (wing of nose) forms the flared posterolateral margin of each nostril

Trunk Region

Partitioned into the thorax and the abdominopelvic region, and the back. Important for the location and condition of the viscera.

Abdominopelvic Region

Portion of the trunk that lies inferior to the rib cage Anterior surface: umbilicus, linea alba (a tendinous structure that extends inferiorly from the xiphoid process to the pubic symphysis). Pubic bones is in the pubic region, underneath the pubic hair. Left and right rectus abdominus muscles and their tendinous intersections. Superior aspect of the ilium terminates anteriorly at the anterior superior iliac spine. Attached to the iliac spine is the inguinal ligament, which forms the inferior boundary of the abdominal wall. This terminates on a small anterior, rounded projection on the pubis called the pubic tubercle. Superior to the medial portion of the inguinal ligament is the superficial inguinal ring. This ring is the superficial opening in the inferior anterior abdominal wall via the inguinal canal, represents a weak spot in the wall.

Occipital Region

Posterior part of the cranium In the center is the external occipital protuberance, a rounded or pointed projection.

Forearm Region

Radius, ulna, and the muscles that control hand movement form the forearm. "Antebrachium" Head of radius can be palpated Styloid process of the radius is readily palpable as the lateral bump along the wrist, while the head and styloid process of the ulna collectively form the medial prominence of the wrist. Pulse of the radial artery can be detected between the distal tendons of the flexor carpi radialis and brachioradialis. Pulse of the ulnar artery is a bit more difficult to find. Can be located by feeling for the medial bump in your hand that is the pisiform bone and then placing your fingers immediately lateral to the bone. Tendons of the extensor pollicis brevis, abductor pollicis longus, and extensor pollicis longus mark the boundary of the triangular anatomic snuffbox. Can palpate the scaphoid bone in this region.

Buccal Region

Refers to the cheek Within this region is the buccinator muscle Superolateral region of the cheek is the location of the zygomatic bone and the zygomatic arch.

Temporal Region

Scalp covers these regions Terminates just superior to the ear Temporalis muscle is attached at the temporal region Running over the temporalis muscle is the superficial temporal artery just posterior to the orbits ad anterior to the auricle of your ear.

Thorax

Superior portion of the trunk sandwiched between the neck superiorly and the abdomen inferiorly. Consists of the chest and the "upper back." Anterior surface of chest are two dominating surface featured of the thorax- the clavicles and the sternum. Clavicles and the suprasternal notch represent the border between the thorax and the neck. Left and right costal margins of the rib cage form the inferior boundary of the thorax. Infrasternal angle is where the costal margins join to form an inverted V at the xiphoid process. Sternum has three components (manubrium, body, and xiphoid process). Sternal angle- can be felt as the elevation between the manubrium and the body. Clinically important b/c it is at the level of the costal cartilage of the second rib, where it is often used as a landmark for counting ribs. Each breast is located lateral to the sternum. The breast has a projection, the nipple, surrounded by a circular, colored region called the areola.

Foot Region

Superior side (dorsum): Tendons of the tibialis anterior, extensor digitorum longus, and extensory hallucis longus all can be clearly observed. Ankle: Can palpate the navicular bone along the dorsum. Can feel pulse of the dorsalis pedis artery either over the navicular or along the dorsal interspace between the first and second metatarsals. Can be checked for circulation problems. Lateral side: base of metatarsal V. Tendon for the fibularis brevis attaches here. Lateral longitudinal arch, the curvature along the lateral side of the foot. Phalanges, metatarsophalangeal (MP) joints, PIP and DIP joints, and toenails. Medial longitudinal arch and head of metatarsal I.

Gluteal Region

The inferior border of the gluteus maximus muscle forms the gluteal fold. The natal cleft extends vertically vertically to separate the buttocks into two prominences. Inferior portion of each buttock, an ischial tuberosity can be palpated; these tuberosities support body weight while seated. Gluteus medius muscle may be palpated only in the superolateral portion of each buttock. The sciatic nerve isn't easily palpable, but knowledge of its location in the buttock region is essential for health-care providers who must give gluteal IM injections.

Occipital Triangle

The larger and more posteriorly placed of the two triangles. Bounded by the omohyoid, trapezius, and sternocleidomastoid muscles. Important because it contains the external jugular vein (may be visible internal to the skin), the accessory nerve, the brachial plexus, and some lymph nodes.

Posterior Triangle

The lateral region of the neck, posterior to the sternocleidomastoid muscle, superior to the clavicle inferiorly, and anterior to the trapezius muscle. Subdivided into two smaller triangles: the occipital and supraclavicular triangles.

Shoulder Region

The scapula, clavicle, and proximal part of the humerous collectively forms the should, and portions of each of these bones are important surface landmarks in this region. Anteriorly, the clavicle and acromion of the scapula may be observed and palpated. The acromion helps form the rounded, superior projection on your shoulder. The rounded curve of the shoulder is formed by the thick deltoid muscle, which is a frequent site for intramuscular injections.

Back Region

When the back is extended, some of the inferior vertebral spines are obscured; instead, a vertically oriented indentation called the median furrow is all that can be seen along the inferior midline of the back. Posterior scapula are observed, including the lateral and medial borders. The spine of the scapula is covered by the trapezius muscle. The triangle of ausculation is a region bordered by three muscles: the rhomboid major, trapezius, and latissimus dorsi. When an individual flexes his or her back, this triangle becomes larger, and the sixth intercostal space becomes subcutaneous. Thus, at this site a physician can hear respiratory sounds more readily through a stethoscope, without their being muffled by the muscles. Iliac Crests mark the superior surface of the ossa coxae.