skeleton. i. skull a. 2 regions 1) cranium( 8 bones) frontal, sphenoid, ethmoid, l & r temporal,...

SKELETON

• I. SKULL• A. 2 regions• 1) cranium( 8 bones)• frontal, sphenoid, ethmoid, L & R temporal, L & R parietal,

occipital

• •

• 2) facial (14 bones)• 2 nasal, mandible, 2 maxillae, 2 zygomatic, 2 inf. Nasal• conchae, 2 lacrimal, 2 palatine, vomer

review

• Facial bones– 13 immovable– 1 movable– Nasal-nose– Mandible-lower jaw– Maxillae- jaw– Zygomatic-cheek bone– Inf. Nasal conchae- lower

nose• Support mucas membrane

Lacrimal- inside eye socket

carries tearsPalatine- palateVomer – betweeen palatine and sphenoid with ethmoid forms nasal septum

review

• Fontanelles – Fibrous membrane areas in infantile skull

connecting cranial bones– Allow skull to be partially compressible for

passage through birth canal– Infant skull bones are thin, frontal bone in 2

parts, and flexible. Therefore less easily fractured

– Anterior fontanelle – behind frontal bone and in front of parietal bone (soft spot)

review

• Axial skeleton– Cranium

– Protects brain– Surface provides muscle attachment for chewing and

head movement– Paranasal sinuses- airfilled cavities formed by cranial

bones» Reduce skull weight» Increase voice intensity

Middle ear

• Malleus – small bone attached to tympanic membrane which gives it the conical shape

• Incus – attached by ligaments to malleus and stapes vibrates when malleus vibrates

• Stapes(stirrup) – vibrations move fluid which stimulate hearing receptors

Hyoid Bone

• Between lower jaw and larynxx

• Not attached to any other bones

• Supports tongue and aids in swallowing

• B. Why is the skull dome shaped ?• 1) protection ( glancing blows• 2) arch shape is very strong

II. Vertebral Column A. 28in long on average B. 33 separate vert. as an embryo sacrum has 5, coccyx has 4 these fuse to make 26 at birth C. column is made up of vert. linked together by cartilage & ligaments ( gives us flexibility) D. 4 curves( cervical -7, thoracic -12, lumbar -5, sacral- 2) 1) thoracic & sacral appear before birth

2) cervical & lumbar occur later (a) cervical forms when baby holds up head (b) lumbar forms when baby begins to walk helps us sit

• F. Individual Vertebrae• ( body, vertebral foramen, transverse process, & spinous

process

• 1) vertebrae are separated by disks filled with fluid • (rupture, herniated)

2) cervical vertebra have transverse foramina passageways for arteries to the brain. 1st – Atlas, 2nd - Axis

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• III. Thoracic Cage• A. Ribs ( true 7pr, false 3pr, & floating 2pr)- 24 total• B. Sternum( breast bone) – 3 parts• (manubrium, body, & xiphoid process)• * Ribs can regenerate if periosteum is left intact.

• IV. Pectoral Girdle ( Shoulder) – 4 bones, function: supports upper limbs,

• attachment for several muscles, support upper limbs• A. Clavicles ( Collar bones) – Medial: articulates with Manubrium

– Lateral end joins the scapulae

• B.Scapula( shoulder blade)- flat surface allows for muscle attachment. Glenoid fossa is where humerus articulates

V. Upper Limbs A. Arm 1) humerus, radius, ulna humerus – longest radius rotates over ulna during pronation. Ulna- doesn’t rotate.

Chest review

• True ribs are attached to sternum by cartilage

• False ribs are connected to the 7th rib• Floating ribs have no connection• Ribs are curved bones attached to vertebra

in back and coastal cartilage in front• Ribs support and protect chest along sides• Ligaments attach clavicle to sternum

Chest review

• 3 parts to the breast bone• Sternum, manubrium, and xyphoid process

• Regeneragting ribs– Ribs are commonly removed during surgeries

that require bone grafts in other parts of the body

– The rib is removed from the periosteum much like a banana is peeled. The periosteum must remain, as it contains osteoblasts which rebuild the new bone

• B. Wrist, hand, & fingers• 1) wrist made up of 8 bones held together by ligaments• Carpals – 2 rows of four bones each.

– Allows for flexion of wrist

• 2) hand has 2 sections• (a) palm area 5 metacarpals• (b) fingers 14 phalanges

• V. Pelvis ( 2 hip bones – coxal bones) 3 parts• ilium, ischium, pubis• A. shaped like a bowl for organs to rest in• B. Differences male/female• 1) pubic arch is larger in female• 2) male pelvis is taller• 3) female pelvis is wider• 4) thigh bones of female are more separated, • pushing knees closer together• C. functions

• Support trunk of body, provide attachment for lower limbs, protect urinary bladder, lg intestine, and reproductive organs

• male female

• Foramen – an opening usually in bone or membrane

• Fossa – depression in a bone or other part

• Tubercle – small, rounded process on bone

terms

• VI. Legs• A. femur ( longest & strongest bone) thigh bone

• Shaft filled with marrow, flattens on lower end so tibia can articulate

• B. Patella ( knee cap) held in place by ligaments• Surrounded by bursa and ligaments

• C. Tibia( shin) & fibula• VII. Foot• A. tarsals, metatarsals, phalanges• B 2 arches ( spring & support)• 1) longitudinal – heel to toe• 2) transverse – across foot

– ligaments

•

Leg and Foot con’t

• Fibula- does not enter into the knee joint– Does not bear any body weight

• Tarsals - 7– Talus – only freely moveable bone joins tibia and fibula– Calcaneus – heel bone, largest– Navicular– Cuboid– Lateral– Intermed– medial

Foot con’t

• 5 metatarsals

• 14 phalanges