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Biology 210 Chapter 8: Skeletal Tissues

Supplement 1

By John McGillMaterial contributed byBeth Wyatt &Jack Bagwell

DIVISIONS OF THE SKELETAL SYSTEMAXIAL SKELETON (80 BONES)

Bones of the Head, Neck, and Torso

APPENDICULAR SKELETON (126 BONES)

Bones of the Upper and Lower Extremeties

• * Total Number of Major Bones in the Body = 206

BONES OF THE AXIAL SKELETON

SKULL28 Bones

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CRANIAL BONES• 8 • Form the

Cranium• Surrounds the

Brain

FRONTAL-1

AnteriorForms Anterior Portion of Cranium (Forehead)& Anterior Cranial Floor & Forms Roofs of Orbits (Eye Sockets)

PARIETAL - 2

SuperiorForms Superior Portion of Cranium

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TEMPORAL - 2

LateralForms Lateral Portion of Cranium& Cranial Floor

OCCIPITAL - 1

PosteriorForms Posterior Portion of Cranium& Cranial Floor

SPHENOID - 1Central

Forms Central Portion of Cranial FloorShape Resembles BatKnown as the “Keystone of the Cranium” B/C the Sphenoid Bone Anchors All the Other Cranial Bones

LateralForms Lateral Walls of CraniumLies in Front of Temporal Bone & Lateral Walls of Orbits

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ETHMOID - 1

Complex, Irregularly Shaped Bone General Location: Between Nasal and Sphenoid Bones

ETHMOID - continued

ETHMOID - continuedWhere the EthmoidBone Can Be Seen in an Articulated Skull:

Medial Walls of OrbitsUpper Portion of Nasal Septum Upper "Ledges" Projecting into the Nasal Cavities Anterior Cranial Floor

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ETHMOID - continuedEthmoid sinuses

associated with ethmoid bonehollow spaces inside ethmoid bone

BONES OF THE AXIAL SKELETON

SKULLFACIAL BONES

• Primarily Form the Face

NASAL - 2Form Bridge of Nose

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MAXILLARY (MAXILLA) - 2Upper JawbonesForm the central portion of the face"Keystone of the Face“

Anchors All Other Facial Bones Except Mandible

Also Forms: Floor of Orbits & Anterior Portion (Most) of Hard Palate

BONES OF THE AXIAL SKELETON

SKULLFACIAL BONES

ZYGOMATIC - 2

CheekbonesAlso Form Lateral Walls of Orbits

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MANDIBLE - 1

Lower JawboneLargest, Strongest Bone of the Face

LACRIMAL - 2

Forms Medial Walls of Orbits

B/T the Maxillary and Ethmoid Bones

Paper Thin BonesUsually Broken in Real Bone Skulls

PALATINE - 2

Shaped like 2 L's facing one another

Horizontal Portion of L's Forms Posterior Portion of Hard PalateVertical Portion of L's Forms Lateral, Posterior Walls of Nasal Cavities

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Palatine Bones

TurbinatesINFERIOR TURBINATES (CONCHAE) - 2

Form Lower "Ledges" That Project into Nasal Cavities Scroll-Shaped

Inferior turbinate (IT)Middle turbinate (MT)

Increase the surface area of the lining of the noseWarms, humidifies, & cleans air

• U=uvula• T=anterior tongue• BoT=base of tongue• See next slide too

Tur b

inat

es

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VOMER - 1

Forms Lower Portion of Nasal Septum

VOMER - 1

BONES OF THE EAR (6)Tiny Bones Located Within Temporal BonesIn Middle Ear3/Ear

MALLEUS (2)INCUS (2)STAPES (2)

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HYOID BONE (1)

U Shaped Bone That Lies in the Neck B/T Mandible and LarynxThe Only Bone in the Body That Doesn’t Form a Joint With Another BoneHeld in Place By Ligaments and MusclesSupports and Provides Muscle Attachment For Muscles That Form Floor of Mouth and Tongue

HYOID BONE (1)

BONES OF THE AXIAL SKELETON

SPINAL (VERTEBRAL) COLUMN (26)

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CERVICAL VERTEBRAE – 7

ATLAS1st Cervical VertebraNamed For Atlas in Greek Mythology

AXIS2nd Cervical VertebraNamed B/C Atlas Pivots Around Axis

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THORACIC VERTEBRAE – 12

LUMBAR VERTEBRAE – 5

SACRUM – 5 FUSED INTO 1

Wedge-Shaped BoneConsists of 5 Separate Vertebrae (Childhood)That Fuse Into 1 After Bones Mature

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COCCYX – 4 OR 5 FUSED INTO 1

TailboneConsists of Separate VetebraeThat Fuse (Like Sacrum)

BONES OF THE AXIAL SKELETON

STERNUM AND RIBS (25)

STERNUM – 1BreastboneDagger-ShapedFlat Bone

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RIBS – 12 PAIRTRUE RIBS – 7 PAIR

Called True Ribs B/C They Attach Directly to the Sternum By Costal Cartilage

FALSE RIBS – 5 PAIRCalled False Ribs B/C:

• 3 PAIR• Attach Indirectly to the

Sternum By the Costal Cartilage of Rib 7 (1st 3 Pair of False Ribs

• #’s 8,9,10 Counting From the 1st True Rib)

• 2 PAIR • Don’t Attach to the Sternum

At All (Last 2 Pair Of False Ribs, #’s 11,12 Counting From the 1st True Rib)

• These Are Also Known as Floating Ribs

STERNUM AND RIBS (25) continued…

Note: Posteriorly, ALL Ribs Are Attached to the Thoracic VertebraeNote: Thorax (Thoracic Cage) = Sternum + Ribs + Vertebral Column, (Creates a Complete Boney Cage)

BONES OF THE APPENDICULAR SKELETON

UPPER EXTREMITIES (64)

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CLAVICLE – 2Collarbone

SCAPULA – 2Shoulder Blade

Shoulder GirdleShoulder Girdle = Clavicle + Scapula

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HUMERUS – 2Long Bone of the Upper Arm

RADIUS – 2Radius and Ulna Are Bones of the ForearmRadius: Thumb Side, Ulna: Little Finger Side

ULNA – 2Radius and Ulna Are Bones of the ForearmRadius: Thumb Side, Ulna: Little Finger Side

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CARPALS – 16

Bones of the Anatomical WristProximal End of Hand

METACARPALS – 10

Bones That Form the Palm of the HandKnuckles = Heads of Metacarpals

PHALANGES – 28

Bones of the Fingers3 in Each Finger, 2 in Each Thumb

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BONES OF THE APPENDICULAR SKELETON

LOWER EXTREMITIES (62)

OS COXAE (COXAL/INNOMINATE) – 2 (PELVIC GIRDLE)

Pelvic/Hip BonesBroadest Bone in the BodyOs Coxae (2) + Sacrum + Coccyx, Forms Complete Boney Ring

FEMUR – 2Thigh BoneLongest, Largest, Strongest Bone

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PATELLA – 2Kneecap

TIBIA – 2Tibia and Fibula Are Bones of the Lower LegTibia: Shin BoneLarger, More Medial and More Superficial Compared to Fibula

FIBULA – 2

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TARSALS – 14

Bones That Form the Heel and the Posterior Portion of the Foot

METATARSALS – 10

Bones That Form the Long Portion of the Foot

PHALANGES – 28

Bones of the Toes; 3 in Each Toe Except Big Toes, 2 in Each Big Toe