BIO 004 · Human Anatomy
The Upper Extremity
Appendicular Skeleton, Upper Extremity
A reference for the upper extremity video and lab. This page covers the pectoral girdle that attaches the limb to the trunk, and the bones of the arm, forearm, and hand, each bone broken out with its key markings.
How to use this sheet
Notes prints the full reference for review.
Study prints as a fill-in-the-blank worksheet to complete while you watch the video or read.
Quiz me is on-screen practice: type the term, or click Reveal to check yourself.
The tables and sequences respond to Study and Quiz too, with a Reveal button on each row.
- Name the bones of the pectoral girdle and explain how the upper limb attaches to the axial skeleton.
- Identify the key markings of the clavicle and the scapula.
- Identify the key markings of the humerus, the radius, and the ulna.
- Name the bones of the hand, including the eight carpal bones in their two rows.
Your pre-work
Work through these the evening before class. None of it is turned in. It is how you learn the material and build your spaced recall.
This is more than a checklist. Ticking these boxes is the start, not the finish. Committing this material to memory and being able to apply it takes considerable time and repeated effort. You are not done when the boxes are checked. Put in the real hours, and keep coming back for frequent recall and review until the material is genuinely yours.
The Upper Extremity, an Overview
The appendicular skeleton is the bones of the limbs and the girdles that attach them to the axial skeleton. Compare the four parts of the upper limb, proximal to distal.
| Part | Region it spans | Bones |
|---|---|---|
| Pectoral girdle | attaches the upper limb to the trunk | clavicle and scapula |
| Arm | shoulder to elbow | humerus |
| Forearm | elbow to wrist | radius and ulna |
| Hand | wrist to fingertips | carpals, metacarpals, and phalanges |
The Pectoral Girdle
Clavicle
- Claviclethe collarbone, an S-shaped bone across the top of the thorax
- Sternal endthe medial end, articulates with the manubrium of the sternum
- Acromial endthe lateral end, articulates with the acromion of the scapula
- The only bony linkthe clavicle is the sole bony attachment of the upper limb to the axial skeleton
Scapula
- Scapulathe shoulder blade, a flat triangular bone on the posterior thorax
- Bordersthe superior, medial, and lateral borders of the triangle
- Spinethe ridge running across the posterior surface
- Acromionthe flat process at the tip of the spine, the point of the shoulder
- Coracoid processthe hook-like anterior process, a muscle attachment
- Glenoid cavitythe shallow socket that receives the head of the humerus
- Supraspinous fossathe hollow above the spine
- Infraspinous fossathe hollow below the spine
- Subscapular fossathe hollow on the anterior surface
Joints of the pectoral girdle
- Sternoclavicular jointsternal end of the clavicle with the manubrium; the only joint linking the upper limb to the axial skeleton
- Acromioclavicular jointacromial end of the clavicle with the acromion of the scapula
- Glenohumeral jointhead of the humerus in the glenoid cavity, the shoulder joint
The Arm and Forearm
Humerus
- Humerusthe single bone of the arm, from shoulder to elbow
- Headthe rounded proximal end that fits into the glenoid cavity
- Anatomical neckthe narrow groove just below the head
- Surgical neckthe narrowing below the tubercles, a common fracture site
- Greater tuberclethe lateral bump near the head, a muscle attachment
- Lesser tuberclethe anterior bump near the head, a muscle attachment
- Intertubercular sulcusthe groove between the tubercles that holds a biceps tendon
- Deltoid tuberositythe roughened ridge on the shaft where the deltoid muscle attaches
- Capitulumthe lateral knob at the distal end, articulates with the radius
- Trochleathe medial spool at the distal end, articulates with the ulna
- Medial epicondylethe medial projection above the trochlea
- Lateral epicondylethe lateral projection above the capitulum
- Olecranon fossathe deep posterior pit that receives the ulna when the elbow straightens
The forearm bones, radius and ulna
The two forearm bones are easy to confuse. Compare them side by side: which side of the forearm each is on, and the markings at each end.
| Bone | Side of the forearm | Proximal (elbow) end | Distal (wrist) end |
|---|---|---|---|
| Radius | lateral, the thumb side | disc-shaped head articulates with the capitulum; neck just below; radial tuberosity, a muscle attachment, below the neck | styloid process on the lateral side; ulnar notch on the medial side receives the head of the ulna, forming the distal radioulnar joint |
| Ulna | medial, the little-finger side | olecranon, the point of the elbow; coronoid process in front; trochlear notch grips the trochlea of the humerus; radial notch on the lateral side receives the head of the radius, forming the proximal radioulnar joint | styloid process on the medial side |
Grooves, nerves, and the joining membrane
- Radial groovean oblique groove on the posterior shaft of the humerus; the radial nerve runs in it
- Ulnar nerve at the medial epicondylethe nerve passes just behind the medial epicondyle, where it can be palpated, the "funny bone"
- Interosseous membranea fibrous sheet, a syndesmosis, spanning the shafts of the radius and ulna; a muscle attachment that also binds the two bones
- Three radioulnar jointsproximal (radial head and radial notch), distal (ulnar head and ulnar notch), and the interosseous membrane between the shafts
The Hand
Carpals, the wrist
- Carpalseight small bones arranged in two rows, forming the wrist
- Proximal rowscaphoid, lunate, triquetrum, and pisiform
- Distal rowtrapezium, trapezoid, capitate, and hamate
A common memory aid for the eight carpals: "So Long To Pinky, Here Comes The Thumb."
Metacarpals and phalanges
- Metacarpalsfive bones forming the palm, numbered 1 to 5 starting at the thumb
- Phalangesthe finger bones, fourteen in each hand
- Thumbthe pollex, has two phalanges, a proximal and a distal
- Fingerseach of the other four has three phalanges, proximal, middle, and distal
The carpal tunnel
- Flexor retinaculuma strong fibrous band roofing the carpal bones; the space beneath it is the carpal tunnel
- Contentsthe long flexor tendons of the fingers and thumb, and the median nerve
- Carpal tunnel syndromenarrowing of the tunnel compresses the median nerve
- Clinically notable carpalscapitate is the largest; scaphoid is the most frequently fractured; lunate is the most frequently dislocated
See also: Bone Histology for the bone tissue, and The Vertebral Column and Thoracic Cage for the axial skeleton the girdle attaches to.
Bone markings vocabulary
Before naming the landmarks on each bone, learn the general vocabulary. Every marking is a projection, a depression, or an opening. These terms repeat on every bone you will study.
| Marking | Type | Description | Example |
|---|---|---|---|
| Process | projection | any bony prominence | mastoid process |
| Tubercle | projection | small rounded bump | greater tubercle of the humerus |
| Tuberosity | projection | large rough projection | deltoid tuberosity |
| Head | projection | bony expansion carried on a neck | head of the humerus |
| Epicondyle | projection | raised area above a condyle | medial epicondyle of the humerus |
| Facet | articular surface | smooth, nearly flat surface | articular facets of vertebrae |
| Fossa | depression | shallow basin | olecranon fossa |
| Sulcus | depression | a groove | intertubercular sulcus |
| Foramen | opening | hole for vessels or nerves | nutrient foramen |
Build the word
Term breakdown
Upper limb bones are named for keys, blades, and beaks, the objects early anatomists thought they resembled. Learning the roots fixes the names.
- append-to hang onappendicular skeleton
- claviculalittle keyclavicle (collarbone)
- scapul-shoulder bladescapula
- glenesocketglenoid cavity
- acromiontip of the shoulderacromion process
- corac-crow, raven (beak)coracoid process
- humer-upper armhumerus
- trochleapulleytrochlea of the humerus
- radi-ray, spokeradius
- ulnaelbow, forearmulna
- olecranonpoint of the elbowolecranon process
- carp-wristcarpals, metacarpals
- meta-beyondmetacarpals (beyond the wrist)
- phalanxrow of soldiersphalanges (finger bones)
- pollexthumbpollex
Draw it from memory Sketch and label before you check
Work on blank paper, from memory, before you look back at the figures. Drawing the bones is how the marking vocabulary above becomes real landmarks.
- Draw the pectoral girdle. Label the clavicle and scapula; on the scapula mark the glenoid cavity, acromion, coracoid process, spine, and the three borders.
- Draw the humerus, radius, and ulna in anterior view. Label the head, greater and lesser tubercles, deltoid tuberosity, capitulum, and trochlea on the humerus; the olecranon, trochlear notch, and styloid processes on the ulna and radius.
- Draw the bones of the hand. Label the eight carpals in two rows, the five metacarpals, and the phalanges (proximal, middle, distal); mark the pollex.
Then check yourself. Compare your drawings against the figures and the marking table above. Whatever you missed is tonight's study list. Redraw it until every landmark lands without looking.
Study questions
Work on answering these in writing, in your own words. They are the questions to bring to class, and good practice for the reasoning the exams ask for.
- Name the two bones of the pectoral girdle and explain how the girdle attaches the upper limb to the axial skeleton.
- Trace the bones of the upper limb from shoulder to fingertips, naming each.
- Compare the radius and the ulna: which is lateral in anatomical position, and which forms the main hinge of the elbow with the humerus?
- Name the three groups of hand bones and how many bones are in each.
Step 2 . Retrieval check
Now explain it back, in your own words.
In 60 words or more, pull together what the video just taught you. Include the key concepts. This is the point where the learning actually sticks. After you submit, your spaced-recall cards for this topic unlock.