THE SKELETAL SYSTEM

Focus on the Pectoral Girdle

General anatomical terms to know

Process

Ramus

Trochanter

Tuberosity

Tubercle

Crest

Line

Spine

Head

Neck

Condyle

Trochlea

Facet

Fossa

Sulcus

Foramen

Canal of meatus

Fissure

Sinus

Appendicular Skeleton

126 bones

Includes

bones of the limbs (arms and legs)

Pectoral girdle (shoulder)

Pelvic girdle (hip)

Allows free movement of upper limb

Loose attachments, few ligaments

allows scapula to move freely

Easily dislocated

Consists of two bones

1. clavicle (collarbone)

2. scapula (shoulder blade)

Pectoral Girdle (the shoulder)

The Clavicle (“little key”; collarbone)

Acts as a brace to hold the arm

away from the thoracic cage

Helps prevent shoulder dislocation

Structures to know:

Sternoclavicular joint – where the

clavicle meets the sternum

Acromioclavicular joint – where the

clavicle meets the scapula

Right Pectoral Girdle - Anterior

clavicle

scapula

Acromioclavicular joint

Sternoclavicular joint

Right Pectoral Girdle -Posterior

The Scapula (“little shovel”)

Anatomy:

Flattened body

Spine (posterior surface)

Supraspinous fossa – above the spine

Infraspinous fossa – below the spine

Subscapular fossa (anterior)

Rotator Cuff Muscles

The Scapula (“little shovel”)

Anatomy continued:

Acromion process = enlarged end of the spine

articulates with the clavicle to form the acromioclavicular joint

Coracoid process = “beak” like process

Points over the top of the shoulder and anchors arm muscles

Suprascapular notch = nerve passageway (suprascapular nerve)

Glenoid fossa (cavity) = shallow socket that receives the

head of the arm

In greek “glene” (socket)

Right Scapula – posterior aspect

Medial border

Lateral border

spine

Suprascapular notch

Coracoid process

acromion Superior border

Glenoid Fossa

Right Scapula – anterior aspect

Medial border Lateral border

Glenoid Cavity

Suprascapular notch

Coracoid process

acromion

Superior border

Appendicular Sketches

I. Scapula

Anterior view

Posterior view

LABEL ALL STRUCTURES LISTED IN NOTES

Spine, acromion, coracoid process, infraspinous/supraspinous

fossa, subscapular fossa, glenoid fossa, suprascapular notch

Anatomy in Clay…

Build a 3D model of a right scapula

Use the models at the front of the room and on the skeletons as reference

Your scapula model should have the following: Show your teacher when you are finished

Spine, supraspinous and infraspinous fossa

Acromion

Coracoid process

Medial, lateral, superior and inferior borders

Suprascapular notch

Glenoid cavity

THE UPPER LIMB

Bones of the Upper limbs

30 separate bones in each

upper limb

Arm, forearm, hand

The arm

The humerus – single typical long bone of the upper arm

Articulates proximally with scapula and clavicle and distally with radius and ulna

Proximal Features:

Head – fits into glenoid cavity of scapula

Greater and lesser tubercles – two bony projections lateral to the head

Separated by the intertubercular sulcus

Anatomical neck – slight constriction just inferior to the head

Surgical neck – most frequently fractured part of the humerus

The right arm (humerus)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

The arm

Features of the Diaphysis:

Deltoid tuberosity – attachment of deltoid (shoulder) muscle

Radial groove – where the radial nerve rests

The right arm (humerus)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

Deltoid tuberosity Deltoid tuberosity

Radial Groove

Greater tubercle

The arm

Distal features:

Epicondyles (protrusions): medial and lateral

Olecranon fossa: posterior pocket; “funny bone”

Coronoid fossa: anterior pocket

Trochlea: (medial) articulates with trochlear notch of the ulna.

Capitulum: (lateral) articulates with head of the radius

The right arm (humerus)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

Deltoid tuberosity Deltoid tuberosity

Radial Groove

trochlea capitulum

Coronoid fossa

Olecranon fossa

Medial

Epicondyle Lateral Epicondyle

Radial fossa

Greater tubercle

Lateral ridge

Medial ridge

Appendicular Sketches

I. Scapula

II. Humerus

Anterior view

Posterior view

LABEL ALL STRUCTURES LISTED IN NOTES

Head, neck, greater/lesser tubercles, deltoid tuberosity, radial

groove, olecranon fossa, coronoid fossa, medial/lateral

epicondyles, trochlea, capitulum

The forearm

Consists of two bones

1. Radius = lateral bone when in anatomical position

2. Ulna = medial bone when in anatomical position

Radioulnar joints = sight of articulation of radius and ulna

Two bones are connected along their entire length by

interosseous membrane

Structures to know: radial tuberosity, styloid process, coronoid process,

olecranon process, trochlear notch

Radius

Ulna

Interosseous membrane

Trochlear Notch

Olecranon Process

Coronoid Process

Proximal Radioulnar joint

Distal Radioulnar joint

Styloid Process (ulna) Styloid Process (radius)

Radial tuberosity

neck

head

Appendicular Sketches

I. Scapula (2: anterior and posterior)

II. Humerus (2: anterior and posterior)

III. Radius and Ulna (1; anterior)

Anterior view

LABEL ALL STRUCTURES LISTED IN NOTES

The Hand

Wrist (carpals) = 8 short bones

Palm (metacarpals) = 5 long bones

Numbered 1(thumb) to 5 (pinky)

Fingers (phalanges)= long bones

Each finger has 3 phalanges

Thumb has 2 phalanges

Phalanges

Metacarpals

Carpals

Ulna Radius

trapezium

trapezoid

scaphoid

capitate

hamate

pisiform

triquetrum

lunate

distal

middle

proximal

Appendicular Sketches

I. Scapula (2: anterior and posterior)

II. Humerus (2: anterior and posterior)

III. Radius and Ulna (1; anterior)

IV. Hand (1; anterior)

Anterior view

LABEL ALL STRUCTURES LISTED IN NOTES

Grab a chromebook and research the origin of the names of

the 8 carpal bones – add this information to your sketch book

Sketches

1. Clavicle (1; anterior or posterior)

Label: sternal and acromial ends

2. Scapula (2; anterior AND posterior labeled)

Label: acromion, coracoid process, spine, infraspinous and supraspinous fossa, medial lateral and superior borders, glenoid cavity, suprascapular notch

3. Humerus (2: anterior AND posterior)

Label: head, surgical neck, anatomical neck, greater and lesser tubercles, intertubercular sulcus, radial groove, deltoid tuberosity, capitulum, trochlea, medial and lateral epicondyles, olecranon and coronoid fossa

4. Radius and Ulna (1: anterior)

Label:

Hand (1: anterior)

Label:

THE SKELETAL SYSTEM

Focus on the Pelvic Girdle and lower limb

General anatomical terms to know

Process

Ramus

Trochanter

Tuberosity

Tubercle

Crest

Line

Spine

Head

Neck

Condyle

Trochlea

Facet

Fossa

Sulcus

Foramen

Canal of meatus

Fissure

Sinus

Function: weight transfer from

upper body to the legs;

designed for stability and

locomotion

more massive than the pectoral

girdle

more firmly attached to the

axial skeleton

Sacroiliac joint = hip + sacrum

Acetabulum = hip + femur

Pelvic Girdle

The Coxal Bones (aka hip bones)

Each coxal bone results from the fusion of three

separate components:

1. The ilium

2. The ischium

3. Pubis

1. The Ilium

Largest, most superior

large surface area for muscle, tendon and ligament

attachment

Iliac crest = “the hip”

Iliac spines = ligaments attach

2. The Ischium (“sit down bone”)

Inferior part of the coxal bone

Ischial tuberosity - supports the body’s weight when

sitting; attachment site for hamstrings

Ischial spine – ligaments attach

3. Pubis

Most anterior part of the coxal bone

Also called pubic bone

Obturator foramen – opening for blood vessels and

nerves to pass from the abdominal cavity to the lower

limbs

The Pelvic Girdle

ilium

ischium

pubis

Coxal bone

(hip bone)

Sacroiliac

joint

Iliac crest

Pelvic brim

Ischial spine

Acetabulum

Pubis

symphysis

Pelvic arch

ilium

Acetabulum

Obturator foramen

iliac crest

iliac spine

pubis

iliac spine iliac spine

iliac spine

Sciatic notch

body

Ischial spine

ischium

Ischial tuberosity

Ischial ramus

Ramus of pubis

Pubic body

New term: Ramus = “branch”

EX: ischial ramus

Appendicular Sketches continue

Sketch #7: PELVIC GIRDLE (two sketches)

Anterior view and lateral view

Label all structures listed in notes

Ilium, ischium, pubis, acetabulum, iliac crest, iliac spines, ischial

spine, ischial tuberosity, obturator foramen

In addition, describe five differences between a male and

female pelvis

Which one is a female pelvis?

How can you tell the difference between a male

and female pelvis?

A B

Male vs Female Pelvis

Female pelvis:

Inlet is larger and more circular

Shallower

Bones are lighter and thinner

Sacrum is shorter and less curved

Ischial spines are shorter

Greater pubic arch; more rounded

Male vs Female

Right Coxal Bone

ilium

ischium

pubis

Obturater foramen

Acetabulum

Posterior Iliac spine

Posterior Iliac spine

Anterior Iliac spine

Anterior Iliac spine

Iliac crest

Sciatic Notch

Ischial Body

Ischial Spine

Ischial Tuberosity

Ischial Ramus

Ramus (pubis)

Body (pubis)

Bones of the Lower Limbs

Thigh = femur

Leg = tibia and fibula

Foot = tarsals, metatarsals and

phalanges

The Femur

Heaviest strongest bone in the body

Head of femur articulates with acetabulum of pelvis girdle

Neck of femur = common fracture site

Slants medially to join with the leg bones which brings the

knees in line with the center of gravity

Structures to know: greater and lesser trochanters, intertrochanteric crest,

gluteal tuberosity, lateral and medial condyles, intercondylar fossa

(notch), patellar surface

The Femur head

neck Greater trochanter

Lesser

trochanter

Gluteal

tuberosity

Lateral condyle Medial condyle

Patellar

surface

Intercondylar

Fossa (notch)

Intertrochanteric crest

The Leg

Two bones connected by interosseous membrane

Tibia (shin) = larger, medial bone

Forms knee joint with femur

Medial malleolus forms the ankle

Fibula = thin and stick-like

No part in forming knee joint

lateral malleolus forms the ankle

Structures to know: medial and lateral condyles, intercondylar eminence,

tibial tuberosity, medial and lateral malleolus, tibiofibular joints, anterior

crest,

Fibula

Tibia

Interosseous membrane

Proximal Tibiofibular joint

Distal Tibiofibular joint

Medial Condyle Lateral Condyle

Head (fibula) Tibial Tuberosity

Intercondylar Eminence

Lateral Malleolus

Anterior Crest

Medial Malleolus

The Foot

Two important functions:

Support of body weight

Serves as a lever to propel our body forward

Tarsals (7 bones)

Calcaneous = heel bone

Talus = “ankle” lies between the tibia and the calcaneous

Metatarsals (5 bones) = sole of foot

Phalanges (14 bones) = toes

Each toe has 3 phalanges except the big toe which has 2

The Foot

Arches of the Foot

3 arches

Two longitudinal (medial and lateral)

One transverse

Ligaments bind the foot bones together

Tendons help hold the bones firmly in the arched position

Weak arches = “flat feet” or “fallen arches”