Upper Limb Anatomy 1

Question 1

What is the body divided into?

Answer 1

1. The main body (head and neck and trunk) 2. The appendages (the paired upper and lower limbs)

Question 2

What is the axial skeleton?

Answer 2

Head neck and trunk

Question 3

What is the appendicular skeleton?

Answer 3

bones of upper and lower limbs, including the bones forming the pectoral (shoulder) girdle and the pelvic girdle

Question 4

What is the main function of upper limb?

Answer 4

To position hand for manipulation and grip activities

Question 5

What is the main function of lower limb?

Answer 5

support body weight, locomotion and maintain balance (not absolute)

Question 6

How are the limbs connected to trunks?

Answer 6

At joints and via connective tissue

Question 7

Why are joints not enough by themselves?

Answer 7

Joints have mechanical importance but stabilised by ligaments and tendons

Question 8

How are the upper limbs joint to the sternum?

Answer 8

-Upper limb forms left and right sternoclavicular joints with upper parts of the sternum (manubrium)

Question 9

How is the upper limb connected to trunk? What type of joints are these?

Answer 9

-Upper limb connected to trunk by left and right sternoclavicular joints -These are true joints -Left and right scapulothoracic joints which are “virtual or “physiological” joints

Question 10

How does muscle activity help the scapula?

Answer 10

1. Muscle activity holds the scapula against the posterior and posterolateral thoracic wall, which is the rib cage 2. Different combinations of muscles that act on the scapula will move it over this surface, and the contact between the scapula and it’s associated with muscle with the thoracic wall is the scapular thoracic joint.

Question 11

How are the lower limbs connected to the trunk?

Answer 11

-by joints between the pelvis and sacrum: the left and right sacroiliac joints -A synovial joint but relativity immobile -The whole of the weight of the head, neck and trunk is transmitted to the pelvis via this joint and this ligaments

Question 12

What are the four regions of the upper limb?

Answer 12

1. Pectoral (shoulder) girdle 2. Arm 3. Foreaem 4. Hand

Question 13

What does the skeleton of the upper limb comprise of?

Answer 13

1. Pectoral girdle (clavicle and scapula) 2. Arm bone (humerus) 3. Pair of parallel bones of the forearm (the radius and ulna) 4. Two rows of small wrist bones (the carpal bones) 5. Bones of main part of hand (the metacarpals) 6. The bones of the digits, including the thumb (the phalanges)

Question 14

What does the medical end of the clavicle articulate with?

Answer 14

thoracic wall of trunk at the manubrium which is the superior part of the sternum or breastbone

Question 15

What does the lateral end of the clavicle articulate with?

Answer 15

the acromion process of the scapular

Question 16

Describe the clavicle and its function

Answer 16

-Clavicle is S shapes and has number of small bony features where muscles and ligaments attach -Clavicle positioned and moved by no. muscles -Clavicle is movable strut supporting the scapula and the rest of the upper limb which are suspended from it -It acts as a struct to hold the rest of the upper limb away from the chest wall allowing the limb a greater range of movement.

Question 17

What is the scapula?

Answer 17

Scapula mainly flat triangular bone with a no. bony features (that are sites of attachment for muscles and ligaments) including processes, ridges, fosse and other structures

Question 18

How does the scapular have another important attachment point?

Answer 18

Important attachment point for muscles is a small hook of bone in the superior scapular, a coracoid process which protrudes anteriorly

Question 19

What is the glenoid fossa?

Answer 19

1. The glenoid fossa is a shallow cup like depression in awakened region of the lateral scapula. 2. This is the socket for the ball and socket shoulder joint

Question 20

What is the scapular spine?

Answer 20

The scapular spine is a ridge of bone dividing the posterior scapula into the infraspinatus and supraspinatus fossae.

Question 21

What is the lateral need of the scapular spine?

Answer 21

Acromion

Question 22

What surface of the scapula is closest to the chest wall?

Answer 22

The anterior surface of the scapula the subscapular fossa is closest to the chest wall.

Question 23

What does the scapula articulate?

Answer 23

1. The clavicle and its acromion 2. The glenohumeral joint (shoulder joint) -The rounded head of the humerus is the bowl that articulates with this socket that is the glenoid fossa.

Question 24

What is the long bone of the humerous?

Answer 24

Largest bone of the upper limb Articulates proximally (superiorly) with the glenoid doss of the scapula to form the shoulder joint Articulates distally (inferiorly) with the radius and ulna to form the elbow joint The various bony features are sites of attachment for muscles and ligaments The grooves accommodate rope-like tendons or nerves

Question 25

What is the structure of the humorous?

Answer 25

It is a long bone with a fairly straight shaft, which has expanded at both its proximal and distal ends where it forms articular structures and sites for muscle attachments

Question 26

What do the proximal ends of bones of forearm articulate with?

Answer 26

the radius and ulna articulate with the distal ends of the humerus to form the elbow joints

Question 27

What do the distal ends of the radius and ulna articulate with?

Answer 27

the proximal row of the carpal bones at the wrist joint with the exception of pisiform (a sesamoid bone)

Question 28

How are the radius and ulna connected along the length of shafts?

Answer 28

-Along the length of the shafts, the radius and ulna are connected by a sheet of fibrous connective tissue known as the interosseous membrane -This structure contributes to the general stability of the arrangement and also acts as a site of muscle attachments.

Question 29

What is the radial tuberosity?

Answer 29

a bony feature that is an important attachment site for the tendon of the biceps muscle.

Question 30

What are carpal bones?

Answer 30

group of 8 small bones arranged as two rows of four: proximal and distal rows

Question 31

What do the proximal row of carpals articulate with?

Answer 31

Proximal row of the carpals articulate with the metacarpals of the hand which in turn articulates with the phalanges of the digits (all digits have three phalanges except the thumb which has two)

Question 32

What does the distal row of the carpal articulate with?

Answer 32

the proximal end of metacarpal bones, basis of metacarpals

Question 33

What does carpal bones also articulate with?

Answer 33

their neighbours in their rows and in the other row

Question 34

What are the metacarpal bones?

Answer 34

small long bones forming the skeleton of the palmar region of the hand.

Question 35

What do the metacarpals articulate at and with?

Answer 35

their base with the distal row of carpals, their heads, which are the knuckles articulate with the proximal phalanges.

Question 36

What are the phalanges?

Answer 36

-bones of the digits -the thumb has two phalanges; a proximal and the distal, while the other digits have three.

Question 37

What is the structure of each phalanges?

Answer 37

Each phalanges has a proximal base, a shaft, and a distal head.

Question 38

What are joints classified by?

Answer 38

1. Their structural properties 2. Their level of mobility

Question 39

What are the different structural classification of joints?

Answer 39

1. Fibrous 2. Cartilaginous 3. Synovial joints

Question 40

What are fibrous joints?

Answer 40

bones connected by fibrous connective tissue, e.g. sutures of skull; syndesmosis in the forearm

Question 41

What are cartilaginous joints? What is an example?

Answer 41

-bones connected with cartilage, e.g. pubic symphysis.

Question 42

What are the two different types of cartilaginous joints?

Answer 42

•Primary (synchondrosis, connected by hyaline cartilage) •Secondary (symphysis, connected by fibrocartilage – mainly in the midline of the body)

Question 43

What is an epiphyseal plate?

Answer 43

-The Epiphyseal Plate illustrated in the previous slide is a structure that is observed in the bones of babies, children and young adults -Epiphyseal plates are temporary cartilaginous joints that allow bone growth. •Epiphyseal plates (dark in X-ray) remain cartilaginous until bone growth ceases, when they ossify •For example, in child’s wrist (upper image) epiphyses ossify in 2nd year

Question 44

What is a synovial joint?

Answer 44

-the articulation is surrounded by an enclosing synovial capsule; bones not directly connected at the joint surfaces but strengthened by surrounding structures (ligaments) -Many examples such as interphalangeal joints. -Articular surfaces generally covered in hyaline cartilage.

Question 45

What are the types of synovial joints?

Answer 45

Generally freely mobile, but mobility may be restricted in some planes. For example - 1. Uniaxial: movement in one direction only e.g. hinge joint. 2 .Biaxial: movement in two different planes e.g. saddle joint. 3. Multiaxial: movement on several axes e.g. ball and socket joint

Question 46

What are the joint mobility classification?

Answer 46

•Synarthosis:- little or no mobility (mostly fibrous joints like skull sutures) •Amphiarthosis:- limited mobility (often fibrocartilaginous such as pubic symphysis) •Diarthosis:- freely mobile (many joints, mostly synovial)

Question 47

The more mobile a joint, the less stable it usually is - for some joints, the shape of the articulating parts of the bones would provide very poor stability on their own. Stability is provided by other structures. What are they?

Answer 47

•Ligaments – collagenous connective tissue linking bones •Tendons – collagenous connective tissue between bones and muscles.

Question 48

What are some other important fascial structures?

Answer 48

•Retinacula (singular retinaculum) •Aponeuroses (singular aponeurosis) •Bursae (singular bursa) -When examining the articulations between bones using disarticulated individual bones, note that the possibilities for movement is often significantly restricted by ligaments. This prevents unwanted movements that would destabilise a joint.

Question 49

What is the retinaculum?

Answer 49

-A retinaculum is thickened band of deep fascia found close to a joint. -This band holds tendons down during muscle contraction to prevent bow-stringing, which might compromise function.

Question 50

What is the aponeurosis?

Answer 50

a flat, sheet-like structure formed from a tendon or ligament

Question 51

What can aponeuroses provide?

Answer 51

-a broad attachment for a muscle which will distribute mechanical load over a larger area than a more typical tendon would -They also can provide protection for underlying structures, e.g. in the palm of the hand and the sole of the foot

Question 52

What is a bursa?

Answer 52

A bursa is a closed sac of a serous membrane, whose interior is similar to that of synovial joints

Question 53

What does bursa membranes secrete and where are they found?

Answer 53

1. The delicate membranes of bursae secrete a lubricating fluid to their interior. 2. Bursae are found at body sites that are subject to friction, where they act as a “bearing” that allows free movement. -Inflammation of a bursa (bursitis) can be extremely painful.