1. Bone Diversity
Dr. Anderson
GCIT

2. Bone Diversity There are normally 206 bones in the adult human body
Each bone is derived from connective tissue and grows to articulate with other bones to form the functional human skeleton

3. The Axial Skeleton
Composed of the skull, vertebrae, ribs (thoracic cage) and coccyx

4. The Skull
Cranium
Made of multiple bones that are immovable (as adult) and connect in sutures, houses the brain

5. The Skull and Mandible

6. Cranium – Frontal Bone (#1)
Shell-shaped frontal bone, anterior to parietal (coronal) sutures
Makes up superior wall of orbits
Makes up most of the anterior cranial fossa and supports the frontal lobe of the brain

7. Cranium – Parietal Bone (#2)
Form most of the superior and lateral aspects of the skull and articulate with other skull bones
Coronal suture
Sagittal suture
Lambdoid suture
Squamous suture

8. Cranium - Occipital Bone (#4)
Forms most of the skull’s posterior walls and base
Internally, forms the walls of the interior cranial fossa which supports the cerebellum
Foramen magnum occurs in the inferior surface of this bone, allowing the spinal cord to pass through

9. Cranium - Temporal Bone (#3)
Inferior to parietal bones (3 regions)
Squamous region
Produces the zygomatic process anteriorly to meet the zygomatic bone (makes up the “cheekbone”) and contains the mandibular fossa (meets the mandible to articulate the lower jaw)
Tympanic Region
Contains acoustic meatus and styloid process
Mastoid region
Exhibits mastoid process (anchors some neck musculature) and has the stylomastoid foramen (allows cranial nerve VII to exit the skull)

10. Cranium - Temporal Bone (#3) (con’d)
Deep to the surface of the skull lies the petrous region of the temporal bone
Makes middle cranial fossa (with sphenoid bone)
Petrous region penetrated by foramina,
The jugular foramen which allow the internal jugular vein and cranial nerves 9-11 to pass through
Carotid canal – allows internal carotid artery to perfuse the brain

11. Cranium - Sphenoid Bone (#5)
Very complex, but articulates with almost all other bones
Spans the width of the middle cranial fossa
Superior surface bears the sella turcica; the “seat” of this saddle shaped pertuberance houses the pituitary gland – the hypophyseal fossa

12. Cranium - Sphenoid Bone (#5) (con’d)
“Batlike” wings
“Greater wings” – form the:
middle cranial fossa (along with temporal bone)
Dorsal walls of the orbits
External wall of the skull
“Lesser wings” -
Form part of the floor of the anterior cranial fossa
Pterygoid processes – anchor chewing muscles

13. Cranium - Sphenoid Bone (#5) - con’d
Openings in sphenoid include
Optic canals – anterior to the sella turcica, allow cranial nerves to pass to the eyes
Superior Orbital Fissure
Allows cranial nerves that control eye movements to exit
Foramina Rotundum, Ovale and Spinosum - allow blood vessels and nerves to reach to front of the face

14. Cranium - Ethmoid Bone
Forms the bony border between the nasal cavities and the orbits (forms medial walls)
Cribiform plates (comprise superior aspect inside skull)
Contain olfactory foramina –
Also forms bony support for sinuses
Crista galli – posterior aspect, attaches to the dura (covering around the brain)

15. Facial Bones - Mandible
Lower Jawbone – articulates with mandibular fossa (on temporal bone)
Two main parts
Body (chin)
Ramus (vertical part)

16. Mandible
Coronoid Process – attachment point for temporalis muscle (levitates jaw)
Alveolar process part of body that contains teeth (alveoli)
Mandibular foramen
houses nerves that provide tooth sensation
Mental Foramina – opening that allows the nerves and blood vessels that serve the chin and lower lip to penetrate

17. Maxillary Bones
Bilateral maxillary bones are fused medially – form the upper jaw and the central part of the face
Palatine Process – forms hard palate
Frontal processes – forms the bridge of the nose
Zygomatic process – extends to form the anterior “cheek”

18. Smaller Facial Bones (pg 213)
Zygomatic bones – form cheek bones
Nasal Bones – forms bridge of nose
Lacrimal Bones – medial orbit walls
Palatine Bones – posterior part of hard palate
Inferior nasal conchae – lateral walls of nasal cavity

19. All of the Aforementioned Bones are Summarized on pp. 214-215

20. The Vertebral Column Consists of 26 irregular (in shape) bones
Segmentation = flexibility!
Prone to damage under heavy and/or chronic forces

21. Vertebral Function Transmits force from upper body to legs
Houses and protects the spinal cord
Attachment points for ribs, and for muscles/ ligaments of the back and neck

22. Spinal Divisions 7 cervical (neck) vertebrae 12 Thoracic vertebrae
5 Lumbar vertebrae
5 Sacral (fused) vertebrae
4 Vertebrae in Coccyx

23. Scoliosis Abnormal curvature of the spine
Leads to gait problems, pain and disability, breathing difficulties
Can be corrected early by bracing, in extreme cases- surgery

24. Ligaments Hold spine straight and prevents hyperextension
Anterior longitudinal ligament – prevents hyperextension backward
Posterior longitudinal ligament – prevents hyperextension forward
Ligament flavum – connects adjacent vertebrae

25. Spinal Arrangement Alternating arrangement of vertebrae and discs
Peripheral nerves from spinal cord extend from each vertebral “level”

26. Intervertebral Discs
Serves as a shock absorber between vertebrae- composed of collagen and fibrocartilage
Composed of 2 layers
Inner, gel-like layer (nucleus pulposus)
Annulus fibrosus – tough outer covering that resists compression

27. Herniated Discs
Injury leads to rupture of the anulus fibrosis leading to a “bulge” which may press on the spinal nerves causing intense pain, numbness or loss of motor fuction

28. Vertebra (Dorsal View)
Centrum bears the weight of the body (interspersed by discs)
Spinal cord passes through the vertebral foramen
Spinous process and transverse process are for muscle attachment

29. Vertebra (Lateral View)
Notches in laminae form intervertebral foramina which allow passage of peripheral nerves
Superior and inferior articular processes are where vertebrae articulate together

30. Vertebral Names Cervical Vertebrae (C1-C7) Thoracic Vertebrae (T1-T12)
Lumbar Vertebrae
(L1-L5)
Sacral Vertebrae
(S1-S5)

31. Superior-Inferior Changes
Centra of each vertebrae tend to thicken inferiorly
Vertebral foramen narrows inferiorly
No rib articulation past T12

32. The Thoracic (Rib) Cage
Roughly cone-shaped
Protects the heart, lungs
Provides a solid foundation for muscles to pull and push against for inhalation and exhalation

33. Sternum
Articulates with the costal cartilages of the ribs (anteriorly)

34. Ribs Serve to protect the organs of the thoracic cavity (heart, lungs)
12 pairs (in both genders)
7 pairs are “true” ribs that articulate directly with sternum
5 pairs are “false” ribs that articulate indirectly with the sternum

35. Posterior Rib Articulation

36. Appendicular Skeleton
Peripheral to axial skeleton
Includes limb bones (arms and legs) and pelvic a shoulder girdles

37. Shoulder (Pectoral) Girdle
Attach upper limbs to the axial skeleton
Major bones
Scapula (shoulder blade)
Posterior aspect
Clavicle (collar bone)
Anterior aspect

38. Clavicles Bilateral and anterior Assymetrical
Sternal end of clavicle articulates with the superior sternum
Acromial end articulates with the glenoid cavity (glenoid fossa) of the scapula
Deltoid tubercle (where deltoid muscle attaches to levitate shoulder
Deltoid tubercle
Deltoid tubercle

39. Scapula Bilateral and posterior
Does NOT articulate directly with the axial skeleton – held in place by muscles
This articulation allows for flexibility at the cost of stability

40. Scapula - Anatomy Triangular bone Notable features
Glenoid cavity (fossa) articulates with the humerus on lateral border
Spine - ends laterally as the acromion, a process that articulates with the clavicle
Coracoid process – projects anteriorly to provide attachment point for biceps

41. Upper Limb (Arm) Bones Humerus – Upper Arm Radius, Ulna – Forearm
Carpal bones – wrists
Metacarpals – palm
Phalanges - Fingers

42. Humerus
Articulates with scapula (proximally) and radius and ulna (distally)
Notable features
Head
Greater and lesser tubercles
Intertubercular sulcus
Deltoid tuberosity
Radial groove
Trochlea
Fossae (coronoid, olecranon, radial)
Proximal
Distal

43. Humerus – Detailed Structure

44. Ulna Forms elbow joint with humerus
Longer forearm bone (on pinky side), thicker proximally
Notable features
Olecranon (elbow)
Coronoid Process
Trochlear notch
Distal head (forms articulation with wrist)
Grips trochlea of humerus, forming articulation proximally

45. Radius Thicker distally Notable features
Proximal head – articulates with capitulum of humerus
Radial tuberosity – provides attachment for bicep
Styloid process – provides attachment for wrist ligament
Proximal
Distal

46. Ulna – Detailed Structure

47. The Hand Carpals – (8 bones total)
Metacarpals (5 bones) labeled 1-5 (thumb to pinky)
Phalanges – multiple bones each
Two in thumb
Three in all other fingers
Distal, middle, proximal

48. The Hand

51. The Pelvic (Hip) Girdle
Attaches lower limbs to the axial skeleton
More stable but less flexible than shoulder girdle
“Pelvis” is actually three separate bones

52. Pelvic Function
Attaches lower appendicular skeleton to the axial skeleton
Firmly attached with ligaments
Provides a strong foundation for femur articulation and muscle attachment

53. Pelvic Bones 3 main parts
Ilium (superior)
Ischium (inferior and posterior)
Pubis (inferior and anterior)
The acetabulum (hip socket) is where all three hip bones fuse and where the femur articulates
Medial view
Lateral view

54. The Ilium Notable features
Greater sciatic notch – where the sciatic nerve passes through to the thigh
Auricular surface – connects pelvis to sacrum, thereby transferring the weight of the upper body to the hip girdle (the sacroiliac joint)

55. Lateral View of Pelvis

56. Ischium and Pubis Ischium Pubis Ischial tuberosity
Bears all weight when sitting
Pubis
Forms anterior part of hip bone
Pubic symphysis (cartilaginous disc connects pubic bones medially)

57. Gender Differences in Pelvic Anatomy
What are the major differences in hip morphology between men and women?

58. The Lower Limb (Leg) Bones
Femur – thigh bone
Tibia – shin bone 1
Fibula – shin bone 2
Tarsals – ankle bones
Metatarsals – foot bones
Phalanges - toes

59. Femur Largest and strongest bone in the body
Transfers all weight from the pelvis to the legs

60. Femur Notable Features Head – articulates with acetabulum in hip
Greater trochanter – attachment point for thigh muscles
Lesser trochanter – attachment point for gluteal muscles
Lateral/medial condyles – articulates at knee joint
Patella – knee cap

61. Tibia Tibia transmits weight of femur to the foot
Lateral and medial condyle articulate with femur (proximal end)
Medial malleolus (distal end) – “bulge” on inside of ankle

62. Fibula Primarily for muscle attachment Lateral Malleolus
Does not bear weight
Lateral Malleolus
“Outside” bump of ankle

63. Ankle and Foot Bones Tarsals – ankle bones
Metatarsals – proximal foot bones
Calcaneus – heel bone
Phalanges - Toes