Upload
5alod
View
180
Download
2
Tags:
Embed Size (px)
Citation preview
AXIAL & APPENDICULAR
SKELETONS
First part
Apr 12, 2023
1
THE SKELETAL SYSTEM
Apr 12, 2023
2
The skeleton consists of• Bones (206)• Cartilages• Joints• Ligaments
Divided into axial and appendicular.
Functions of Skeletal System
Apr 12, 2023 3
1) Support – provides solid axis for muscles to act against, creating motion.
2) Protection- bones such as skull provide barrier of protection from external forces.
3) Hematopoiesis-production of blood cells.
4 )Mineral storage (calcium especially).
22 bones in skull
6 in middle ears
1 hyoid bone
26 in vertebral column
25 in thoracic cage
4 in pectoral girdle
60 in upper limbs
60 in lower limbs
2 in pelvic girdle
206 bones in all
Apr 12, 20234
Bone
Types of Bones Bones are classified
into 4 types :-
A. LongB. FlatC. IrregularD. short
Apr 12, 2023 5
Long BonesFound in the limbsEach bone is made
of a body (diaphysis) and two
extremities (epiphyses)
Wall consists of dense tissue
Central canal called medullary canal is filled with marrow
Apr 12, 2023 6
Short Bones
Found in skeleton where strength, compactness, and limited movement are desired
2 main examples Tarsus Carpus
Apr 12, 2023 7
Flat Bones
Used in spots where protection or muscular attachment is desired
Main locations are skull and scapula
Apr 12, 2023 8
Irregular Bones
Bones which don’t fit into other categories due to irregular shapes
Examples: vertebrae, sphenoid, hyoid
Apr 12, 2023 9
Skull.Vertebral column.Thoracic cage.
Axial skeleton is shown in green
Apr 12, 202310
Axial skeleton
The Skull
Apr 12, 2023
11
Cranial bones (or cranium) Enclose the cranial cavity, which supports and
protects the brain Attachment sites for some head and neck
muscles
Facial bones (anterior aspect of skull) Form framework of face. Form cavities for sense organs of light, taste and
smell. Provides openings for passage of air and food. Hold the teeth. Anchor the muscles of the face.
Cranial bones
Apr 12, 2023
12
parietal
parietal
frontal
temporalparietal
occipital
_______sphenoid_____ethmoid
occipital
Apr 12, 2023
13
Facial Bones
Mandible- lower jaw bone
Maxillary bones (maxillae) fuse together to form upper jaw
Palatine processes – directly posterior to maxillae; forms rear of hard palate
Apr 12, 2023 14
Facial Bones Contd. Zygomatic bones – cheekbones
Lacrimal bones – inferior section of orbital bones; provides passageway for tears
Ethmoid bone- forms roof of nasal cavity
Apr 12, 2023 15
More Facial Bones Nasal bones- form
bridge of nose
Vomer – divides nasal cavity in half
Inferior conchae- thin curved bones which project from interior of nasal cavity
Apr 12, 2023 16
Apr 12, 2023 17
Mandible
Paranasal sinuses
Apr 12, 2023
18
Air-filled sacs in the bones “Paranasal” because they cluster around
and connect to the nasal cavity
Sutures
Apr 12, 2023
19
Immovable, interlocking joints of flat bones of skull
Irregular, saw-toothed appearance Largest 4 skull sutures: where bones
articulate with parietal bones Coronal Sagittal Squamous Lambdoid
Fontanels
Apr 12, 2023
20
Unossified remnants of membranes
Present at birth Anterior fontanel
largest Called “soft spots” Ossify by 1 ½ - 2
years
Hyoid bone
Apr 12, 2023
21
Only bone which does not articulate with any other bone.
Moveable base for the tongue.
Points of attachment for neck muscles that raise and lower the larynx during swallowing.
The Thoracic Cage
Made of bones which connect and protect heart and lungs
Ribs, Costal Cartilage, and Sternum
Apr 12, 2023 22
Ribs
12 pairs of ribs, each connects to a thoracic vertebrae
First 7 pairs = true ribs; attach directly to sternum
Last 5 pairs = false ribs; indirect or no attachment; last two are floating (no sternal attachment)
Apr 12, 2023 23
Apr 12, 2023
24
Typical rib
Sternum
Fusion of three bones
1 )Manubrium (top)2 )Body (middle)3 )Xiphoid Process
(bottom)Location for rib
attachmentSurrounded by
costal cartilageApr 12, 2023 25
The Vertebral Column
Apr 12, 2023
26
Adult: 24 vertebrae Inferior 9 have fused
forming
The sacrum (5)
The coccyx (4)
Structure of a typical vertebra
Apr 12, 202327
Cervical Vertebrae
Apr 12, 2023
28
Smallest
Transverse processes have foramina (transverse foramen)
Spinous process bifid (forked) except for C7
Thoracic Vertebrae T1-T12
Apr 12, 2023
29
Heart shaped body
The spinous process are long, sharp and directed downwards
Lumbar Vertebrae L1-L5
Apr 12, 2023
30
Massive blocklike bodies
The spinous processes short, thick, broad and directed backward
Sacrum and Coccyx
Apr 12, 2023
31