AP1 M 4.2 Anatomy of the skeleton Appendicular

Question 1

acetabulum

Answer 1

The head of the femur articulates with the pelvic girdle at the acetabulum, called the hip joint. Note the other important bone landmarks of the femur in Figure 4.32 below.

Question 2

acromion process

Scapula Bone Landmarks

Answer 2

The acromion process projects from the scapular spine, which can be seen from both the posterior and anterior views (Figure 4.23). The acromion process connects to the clavicle anteriorly.

Question 3

appendicular skeleton

Answer 3

The appendicular skeleton (Figure 4.20) consists of the bones within the pectoral and pelvic girdles and the attached limbs. The pectoral (shoulder) girdle and upper limbs (arms) are specialized for flexibility and increased range of motion, while the pelvic girdle and lower limbs are specialized for strength.

Question 4

Bones of the Hand

Answer 4

The many bones of the hand increase its flexibility (Figure 4.27)

Question 5

capitulum

humerus

Answer 5

The capitulum articulates with a small portion of the radius.

Question 6

carpal bones

Answer 6

The wrist has eight carpal bones, which look like small pebbles. The proximal row of carpal bones (from lateral to medial) are scaphoid, lunate, triquetral, and pisiform. The distal row of carpal bones (from lateral to medial) are trapezium, trapezoid, capitate, and hamate.

Question 7

Dislocation

Answer 7

Dislocation of a joint means that the bone is removed from its socket. Dislocation of the shoulder occurs when the head of the humerus is removed from the glenoid cavity in any direction.

Question 8

femur

Answer 8

The largest, longest single bone in the body is the femur (Figure 4.32).

Question 9

fibula

Answer 9

In the lower leg, there are two bones: the tibia (medial) and fibula (lateral). Both bones of the lower leg have a prominence that contributes to the ankle, the lateral malleolus of the fibula on the lateral side of the ankle.

Question 10

first metacarpal

Answer 10

The first metacarpal is the thumb, and the fifth metacarpal is the pinky. The metacarpal bone that leads to the thumb is placed in such a way that the thumb can reach out and touch the other digits. (Digits is a term that refers to either fingers or toes.)

Question 11

foot

Answer 11

The foot, like the hand, is made up of many smaller bones (Figure 4.34).

Question 12

hallux

Answer 12

The great toe (hallux) is the first metatarsal. Like the thumb, the great toe only has a distal and proximal phalanx. Metatarsals 2-5 all have a distal, middle, and proximal phalanx.

Question 13

medial epicondyle

humerus

Answer 13

The medial epicondyle of the humerus can be palpated on the medial side of the arm at the elbow.

Question 14

humerus

Answer 14

The humerus is comprised of the head, neck, shaft, capitulum, and trochlea (Figure 4.25)

Question 15

humerus

Answer 15

The single long bone in the upper arm, the humerus (Figure 4.24), has a smoothly rounded head (Figure 4.25) that fits into a socket of the scapula at the glenoid cavity (Figure 4.23). The glenoid cavity is very shallow and much smaller than the head of the humerus. The humerus needs to be held to the shallow glenoid cavity by the rotator cuff muscles and other ligaments. The structure of the shoulder permits movement of the arm in almost any direction but provides little stability. The gleno-humeral joint is prone to dislocation because it is held in place primarily by muscular and ligament attachment with very little bony stability.

Question 16

trochlea

humerus

Answer 16

The trochlea articulates with the ulna

Question 17

ilium

pelvic

Answer 17

The ilium is the most superior of the sections and can be palpated on the lateral sides of the hips.

Question 18

ischium

pelvic

Answer 18

The ischium is located posteriorly. The ischium bones are also known as the “sits” bones as these are the bony landmarks that can be felt when sitting upright in a chair.

Question 19

lateral epicondyle

humerus

Answer 19

The lateral epicondyle of the humerus can be palpated on the lateral side of the arm at the elbow.

Question 20

metacarpal bones

Answer 20

From the carpal bones, five metacarpal bones fan out to form a framework for the palm.

Question 21

metatarsal

Answer 21

Five metatarsal bones span the distance between the ankle and toes. As a result, the foot has longitudinal arches from the heel to the toes and a transverse arch across the foot. These provide a stable, springy base for the body. Flat feet is a condition that is likely to occur if the tissues binding the metatarsals together become weakened.

Question 22

ASIS

Important bone landmarks

Answer 22

The ASIS (anterior superior iliac spine. located on the anterior portion of the ilium

Question 23

The Lower Extremities

Answer 23

The weight of the body is transmitted through the pelvis to the legs and then onto the ground.

Question 24

pubic arch

Answer 24

There are several differences in the male and female pelvic girdles. The pubic arch (Figure 4.31) is wider in females than in males. The pubic brim, also known as the pelvic outlet, (Figure 4.31) is shaped more like a circle in males and an oval in females. These differences are to accommodate childbearing.

Question 25

AIIS

Important bone landmarks

Answer 25

AIIS (anterior inferior iliac spine) are located on the anterior portion of the ilium.

Question 26

neck

Scapula Bone Landmarks

Answer 26

The neck of the scapula on the lateral side contains the glenoid cavity, where the head of the humerus articulates with the scapula. The anterior side of the scapula contains the subscapular fossa

Question 27

olecranon process

Answer 27

The olecranon process of the ulna is the prominent bone that can be palpated in the elbow posteriorly (Figure 4.26). When the arm is held in anatomical position (so that the palm is turned anteriorly), the radius and ulna are almost parallel to one another. When the arm is turned so that the palm is next to the body the radius crosses in front of the ulna, a feature that contributes to the easy twisting motion of the forearm (pronation).

Question 28

patella

Answer 28

The patella (Figure 4.33) sits anteriorly to the femur, formed within the quadriceps femoris tendon.

Question 29

pectoral girdle

Answer 29

The pectoral girdle (Figure 4.21), also known as the shoulder girdle, is composed of two clavicles and two scapulae. Each clavicle (collarbone) connects with the sternum anteriorly and the scapula (shoulder blade) posteriorly (Figure 4.21). The scapula is freely movable and held in place only by muscles and ligaments. The attachment of the scapula allows it to follow the many movements of the arm.

Question 30

pelvic girdle

Answer 30

The pelvic girdle consists of two heavy, large coxal bones (Figure 4.29). The coxal bones, also called ossa coxae or innominate bones, are anchored to the sacrum posteriorly via a network of ligaments. Together, these bones form a hollow cavity. The coxal bones are symmetrical and formed by the fusion of three bones: the ilium, ischium, and pubis.

Question 31

phalanges

Answer 31

Beyond the metacarpals are the phalanges, the bones of the fingers and the thumb. The phalanges of the hand are long, slender, and lightweight. The thumb, or first digit, is composed of two phalanges, while all other digits have three (Figure 4.28).

Question 32

phalanges

Answer 32

The bones of the toes are called phalanges, just like those of the fingers.

Question 33

pubis

pelvic

Answer 33

The pubis forms the center anteriorly, connected by the pubic symphysis (Figure 4.29).

Question 34

scapula

Answer 34

The scapula (shoulder blade) posteriorly (Figure 4.21). The scapula is freely movable and held in place only by muscles and ligaments. The attachment of the scapula allows it to follow the many movements of the arm

Question 35

coracoid process

Scapula Bone Landmarks

Answer 35

The coracoid process projects anteriorly from the scapula, allowing for muscular attachment.

Question 36

glenoid cavity

Scapula Bone Landmarks

Answer 36

The neck of the scapula on the lateral side contains the glenoid cavity, where the head of the humerus articulates with the scapula.

Question 37

Scapula Bone Landmarks

Answer 37

The surfaces of the scapula are important because of the many muscles and ligaments that attach to it. The major bone landmarks are noted in the figures below (Figure 4.22, Figure 4). The posterior side of the scapula (Figure 4.22) contains the supraspinatus fossa, infraspinatus fossa, and scapular spine. The acromion process projects from the scapular spine, which can be seen from both the posterior and anterior views (Figure 4.23). The acromion process connects to the clavicle anteriorly. The neck of the scapula on the lateral side contains the glenoid cavity, where the head of the humerus articulates with the scapula. The anterior side of the scapula contains the subscapular fossa. The coracoid process projects anteriorly from the scapula, allowing for muscular attachment.

Question 38

tarsal bones

Answer 38

There are seven tarsal bones that make up the ankle: medial cuneiform, intermediate cuneiform, lateral cuneiform, navicular, cuboid, talus, and calcaneus.

Question 39

tibia

Answer 39

In the lower leg, there are two bones: the tibia (medial) and fibula (lateral). The larger of the two bones, the tibia, has a ridge that can be easily palpated anteriorly. Both bones of the lower leg have a prominence that contributes to the ankle, the medial malleolus of the tibia on the medial side of the ankle

Question 40

ulna and radius

Answer 40

The distal end of the humerus meets the two bones of the lower arm, the ulna and radius, at the elbow (Figure 4.26)