The Skeletal System Slide 2 Divisions of the Skeletal System The
human skeletal system is divided into two major divisions Axial
Skeleton Appendicular skeleton Slide 3 Axial Skeleton The axial
skeleton contains the bones of the head, neck, and torso (80 bones
total) Slide 4 appendicular skeleton The appendicular skeleton
contains the bones of the upper and lower extremities (126 bones
total) Slide 5 Human Skeleton The human skeleton has a total of 206
bones in all Slide 6 Bones Functions: Support Protection Movement
Storage Blood cell formation Slide 7 Bones Function- Support Form
the internal framework that supports and anchors all soft organs
Slide 8 Bones Function- Protection Bones protect soft body organs
Ex. Skull protects brain Slide 9 Bones Function- Movement Skeletal
Muscles attach to bones by tendons Bones are used as levers to move
body Slide 10 Bones Functions-storage Fat is stored in internal
cavities of bones Slide 11 Bones Functions-storage Store minerals
Most importantCalcium and phosphorus Slide 12 Bones
Functions-storage Calcium in its ion form (Ca 2+ ) must always be
present in blood for nervous system to transmit messages For
muscles to contract For blood to clot Bones are a storage place for
Calcium Slide 13 Bones Functions-storage Blood cell formation
Hematopoiesis (formation of blood cells) occurs in the cavities of
bone marrow Slide 14 Bones Classification of bones 2 basic types of
bone types Compact Bone Spongy Bone Slide 15 Bones Compact Bone
Dense Looks smooth Slide 16 Bones Spongy Bone Small needle-like
pieces of bone Lots of open space Slide 17 Slide 18 Shapes of Bones
Long Bones Short Bones Irregular Bones Slide 19 Bones Long Bones
Longer than they are wide Usually have a shaft with heads at both
ends Mostly compact bones most bones of limbs Slide 20 Bones Short
Bones Generally cube-shaped Mostly spongy bone Ex. Patella (knee
cap), bones of wrist and ankle Slide 21 Flat Bones Thin, flattened,
usually curved Two thick layers of compact bone sandwiching a layer
of spongy bone Bones of skull, ribs, sternum Slide 22 Irregular
Bones Dont fit other categories Ex. Vertebrate, hip bone Slide 23
Structure of a long bone Diaphysis- Shaft Makes up most of the
bones length Composed of compact bone Covered and protected by
periosteum Slide 24 Structure of a long bone Cavity of shaft In
infants- this area forms blood cells Red marrow In adults primarily
filled with yellow marrow (adipose) Called yellow marrow cavity or
medullary cavity Red marrow is confined to spongy bone Slide 25
Structure of a long bone Epiphyses- the ends of the long bone
Epiphyseal line Thin line spanning the epiphysis Slide 26 Structure
of a long bone Epiphyseal plate Plate of hyaline cartilage Causes
the lengthwise growth of a long bone By end of puberty the plate is
completely replaced by bone Slide 27 Structure of Long Bone
Surfaces of bones arent smooth Bumps, holes, and ridges Bone
markings Reveal where muscles, tendons, and ligaments were attached
Reveal where blood vessels and nerves passed Slide 28 Structure of
Long Bone Bone markings Projections or processes- Grow out from the
bone surface Depressions or cavities Indentations in the bone Slide
29 Structure of a long Microscopic anatomy Compact bone: To the
naked eye looks very dense With microscope we see a much different
picture! Slide 30 Structure of a long Microscopic anatomy Compact
bone Passageways carrying nerves and blood vessels Provides living
bone with nutrients and route for waste disposal Slide 31 Structure
of Long Bone Osteocytes The mature bone cells Found in cavities of
the bone matrix called lacunae ( a very tough matrix) Slide 32
Structure of Long Bone Osteocytes Lacunae arranged in concentric
circles called lamellae Lacunae arranged around central (Haversian)
canals Slide 33 Structure of Long Bone Perforating (Volkmanns)
canals Run into the compact bone at right angles to the shaft Let
the inside of bone communicate with outside Slide 34 Bone
Formation, Growth, and Remodeling Embryos skeleton Primarily
hyaline cartilage Young child Most of cartilage has been replaced
by bone Remains in isolated areas Bridge of nose Parts of ribs
joints Slide 35 Bone Formation, Growth, and Remodeling Most bones
develop using hyaline cartilage structures as their models
Ossification- the formation of bone Slide 36 Bone Formation,
Growth, and Remodeling Ossification 2 major stages 1. hylane
cartilage model is completely covered with bone by bone forming
cells called osteoblasts Slide 37 Bone Formation, Growth, and
Remodeling Ossification Step Two: Hyaline cartilage model is
digested away Opens up a medullary cavity within newly formed bone
Slide 38 Bone Formation, Growth, and Remodeling By birth Most
hyaline cartilage models have been converted to bone Excepts two
reasons Articular cartilages cover bone ends Epiphyseal plates
Slide 39 Bone Formation, Growth, and Remodeling Articular
cartilages Persist for life Reduce friction at the joint surfaces
Slide 40 Bone Formation, Growth, and Remodeling How is the
articular cartilage injured? Trauma- twisting, sport injury Certain
diseases Gradually over time Slide 41 Bone Formation, Growth, and
Remodeling When there is significant loss of the articular
cartilage, the knee is considered to have arthritis. Slide 42 Bone
Formation, Growth, and Remodeling Epiphyseal plates Provide for
longitudinal growth of long bones during childhood New cartilage is
formed on external surface Old cartilage is broken down and
replaced by bony matrix Slide 43 Bone Formation, Growth, and
Remodeling Epiphyseal plates Growth controlled by hormones Ends
during adolescence, when the epiphyseal plates are completely
converted to bone Slide 44 Bone Formation, Growth, and Remodeling
How do bones widen? called Appositional Growth Osteoblasts in the
periosteum add bone to the external face Osteoclasts in the
endosteum remove bone from inner wall Slide 45 What happens when
long bone growth ends? Slide 46 Bone Formation, Growth, and
Remodeling Bone Remodeling Bones continually remodeled in response
to 2 factors: 1. calcium levels in the blood 2. the pull of gravity
and muscles on the skeleton Slide 47 Bone Formation, Growth, and
Remodeling Bone Remodeling When blood calcium levels are low
Parathyroid hormone (PTH) is released into blood PTH activates
osteoclasts (bone destroying cells) to break down bone matrix and
release calcium Slide 48 Bone Formation, Growth, and Remodeling
Bone Remodeling When blood calcium levels are too high
(hypercalcemia) Calcium is deposited in bone matrix as hard calcium
salts Slide 49 Bone Formation, Growth, and Remodeling Bone
Remodeling Essential for bones to: retain normal proportions
Strengthen as body increases size and weight Slide 50 Bone
Formation, Growth, and Remodeling Bone Remodeling Bedridden or
physically inactive people tend to lose bone mass and atrophy
Because they arent subjected to stress Slide 51 Bone Formation,
Growth, and Remodeling Rickets Disease of children in which bones
fail to calcify Bones soften and definite bowing of weight-bearing
bones of legs occurs Slide 52 Bone Formation, Growth, and
Remodeling Rickets Called osteomalacia in adults Causes Usually due
to lack of calcium in diet Or lack of vitamin D Is needed to absorb
calcium Slide 53 Divisions of the Skeletal System Axial Slide 54
Bones of the Axial Skeleton Bones of the axial skeleton are divided
into four major groups 1) Bones of the Skull 2) Hyoid Bone 3) Bones
of the Spinal Column 4) Sternum and Ribs Slide 55 Bones of the
Axial Skeleton Bones of the Skull (28 total) Cranial Bones (8
total) form the cranium which surrounds the brain Slide 56 Bones of
the Axial Skeleton Bones of the Skull (28 total) Cranial Bones 1)
Frontal Bone (1 bone) Anterior Portion of Cranium (Forehead) Forms
Anterior Cranial Floor Forms the Roofs of Orbits (Eye Sockets)
Slide 57 Bones of the Axial Skeleton Bones of the Skull (28 total)
Cranial Bones 2) Parietal Bone (2 bones) Forms Superior Portion of
Cranium Slide 58 Bones of the Axial Skeleton Bones of the Skull (28
total) Cranial Bones 3) Temporal Bone (2 bones) Forms Lateral
Portion of Cranium & Lateral Cranial Floor Slide 59 Bones of
the Axial Skeleton Bones of the Skull (28 total) Cranial Bones 4)
Occipital Bone (1 bone) Forms Posterior Portion of Cranium &
Posterior Cranial Floor Slide 60 Bones of the Axial Skeleton Bones
of the Skull (28 total) Cranial Bones 5) Sphenoid Bone (1 bone)
Forms central portion of cranial floor Known as the keystone of the
cranium because the sphenoid bone anchors all the other cranial
bones Slide 61 Bones of the Axial Skeleton Bones of the Skull (28
total) Cranial Bones 6) Ethmoid Bone (1 bone) Complex, irregularly
shaped bone found between the nasal and the sphenoid bones Slide 62
Bones of the Axial Skeleton Bones of the Skull (28 total) Facial
Bones 1) Nasal Bone (2 bones) Forms the bridge of the nose Slide 63
Bones of the Axial Skeleton Bones of the Skull (28 total) Facial
Bones 2) Maxillary bone (2 Bones) Upper jawbone that forms the
central portion of the face Forms the floor of the orbits and the
anterior portion of the hard palate Slide 64 Bones of the Axial
Skeleton Bones of the Skull (28 total) Facial Bones 3) Zygomatic
Bone (2 Bones) Forms the cheekbones and the lateral walls of the
orbits Slide 65 Bones of the Axial Skeleton Bones of the Skull (28
total) Facial Bones 4) Mandible Bone (1 Bone) Lower jawbone Largest
and strongest bone of the face Slide 66 Bones of the Axial Skeleton
Bones of the Skull (28 total) Facial Bones 5) Lacrimal Bone (2
Bones) Forms the medial walls of the orbits Bones are paper thin
Slide 67 Bones of the Axial Skeleton Bones of the Skull (28 total)
Facial Bones 6) Palatine Bone (2 Bones) Forms posterior portion of
the hard palate and forms the lateral and posterior walls of the
nasal cavity Slide 68 Bones of the Axial Skeleton Bones of the
Skull (28 total) Facial Bones 8) Vomer Bone (1 Bone) Forms the
lower portion of the nasal septum Slide 69 Bones of the Axial
Skeleton Bones of the Skull (28 total) Bones of the Ear Three tiny
bones located in the middle ear 1) Malleus (2 Bones) 2) Incus (2
Bones) 3) Stapes (2 Bones) Slide 70 Bones of the Axial Skeleton
Bones of the Skull (28 total) Bones of the Ear Smallest bones in
the body Carry sound vibrations to inner ear Amplifies sound about
7x Slide 71 Bones of the Axial Skeleton Hyoid Bone (1 total) The
hyoid bone is a U shaped bone found in the neck between the
mandible and the larynx It is the only bone in the body which does
not form a joint with another bone (held in place by ligaments and
muscles) Slide 72 Bones of the Axial Skeleton Hyoid Bone (1 total)
Function: Supports the base of the tongue Slide 73 Bones of the
Axial Skeleton Vertebral Column Spine 26 irregular bones connected
by ligaments Flexible, curved structure Slide 74 Bones of the Axial
Skeleton Vertebral Column Spine Running through the central cavity
of vertebral column is the delicate spinal cord Spine preserves and
protects spinal cord Slide 75 Bones of the Axial Skeleton Vertebral
Column Spine Single vertebrae are separated by pads of flexible
fibrocartilage called intervertebral discs They cushion the
vertebrae and absorb shock Slide 76 Bones of the Axial Skeleton
Vertebral Column Spine Young Person Discs have high water content (
90%) Discs are spongy and compressible Slide 77 Bones of the Axial
Skeleton Vertebral Column Spine Aging The water content of disc
decreases Drying of discs and weakening of ligaments predisposes
older people to herniated discs (slipped disc) if slipped disc
presses on spinal cord- major pain Slide 78 Bones of the Axial
Skeleton Vertebral Column Spine The spine has 2 curvatures 1.
Primary Curvature 2. Secondary Curvature Slide 79 Bones of the
Axial Skeleton Vertebral Column Spine Primary Curvature- curvature
in the thoracic and sacral regions Called primary because it is
there when we are born Slide 80 Bones of the Axial Skeleton
Vertebral Column Spine Secondary Curvature- Cervical curvature-
develops when baby begins to lifts its head Lumbar curvature-
develops when baby begins to walk Slide 81 Bones of the Axial
Skeleton Several types of abnormal spinal curvature 1. Scoliosis-
Slide 82 Bones of the Axial Skeleton Several types of abnormal
spinal curvature 2. lordosis- Slide 83 Bones of the Axial Skeleton
Several types of abnormal spinal curvature 2. lordosis- Slide 84
Several types of abnormal spinal curvature 3. kyphosis- Slide 85
Slide 86 Slide 87 Bones of the vertebral column (backbone) Slide 88
Bones of the Axial Skeleton Bones of the Spinal Column (26 total)
1) Cervical Vertebrae (7 Bones) Top seven vertebrae of the spinal
column The atlas (to bear )is the first cervical vertebrae The axis
is the second cervical vertebrae Slide 89 Bones of the Axial
Skeleton Bones of the Spinal Column (26 total) 1) Cervical
Vertebrae (7 Bones) Slide 90 Bones of the Axial Skeleton Bones of
the Spinal Column (26 total) 2) Thoracic Vertebrae (12 Bones)
Middle 12 vertebrae of the spinal column Slide 91 Bones of the
Axial Skeleton Bones of the Spinal Column (26 total) 3) Lumbar
Vertebrae (5 Bones) Bottom five vertebrae of the spinal column
Slide 92 Bones of the Axial Skeleton Bones of the Spinal Column (26
total) 4) Sacrum (5 Bones Fused Into 1 Bone) Five separate
vertebrae that fuse into 1 bone after the bones mature Slide 93
Bones of the Axial Skeleton Bones of the Spinal Column (26 total)
5) Coccyx (4 or 5 Bones Fused Into 1 Bone) Tailbone; consists of
separate vertebrae that have fused together Slide 94 Slide 95 Bones
of the Axial Skeleton Sternum and Ribs (25 total) Sternum (1 Bone)
Breastbone Slide 96 Bones of the Axial Skeleton Ribs You have two
types of ribs 1. True Ribs 2. False Ribs Slide 97 Bones of the
Axial Skeleton Sternum and Ribs (25 total) Ribs (12 pairs = 24
Ribs) True Ribs (First 7 pairs) Ribs attach directly to the sternum
by costal cartilage Slide 98 Bones of the Axial Skeleton Ribs False
Ribs (Bottom 5 pairs) Rib pairs 8, 9, & 10 attach indirectly to
the sternum by the costal cartilage of rib pair #7 Rib pairs 11
& 12 are called floating ribs because they do not attach to the
sternum at all Slide 99 Bones of the Axial Skeleton All ribs attach
to a thoracic vertebrae posteriorly Slide 100 Bones of the Axial
Skeleton Bones of the Upper Extremities The sternum, ribs, and
vertebral column create the thorax Slide 101 Bones of the
Appendicular Skeleton Bones of the Upper Extremities Clavicle (2
Bones) Collarbone Slide 102 Bones of the Appendicular Skeleton
Bones of the Upper Extremities Scapula (2 Bones) Shoulder Blade
Slide 103 Bones of the Appendicular Skeleton Bones of the Upper
Extremities The scapula and clavicle together make up the shoulder
girdle Slide 104 Bones of the Appendicular Skeleton Bones of the
Upper Extremities Humerus (2 Bones) Long bone of the upper arm
Slide 105 Bones of the Appendicular Skeleton Bones of the Upper
Extremities Radius (2 Bones) Ulna (2 Bones) The radius and ulna are
bones of the forearm The radius is on the thumb side and the ulna
is on the little finger side Slide 106 Bones of the Appendicular
Skeleton Bones of the Upper Extremities Carpals (16 Bones; 8 in
Each Hand) Bones of the wrist Slide 107 Bones of the Appendicular
Skeleton Bones of the Upper Extremities Metacarpals (10 Bones, 5 in
Each Hand) Bones in the palm of the hand Slide 108 Bones of the
Appendicular Skeleton Bones of the Upper Extremities Phalanges (28
Bones, 14 in Each Hand) Bones of the fingers (3 in each finger and
2 in the thumb) Slide 109 Bones of the Appendicular Skeleton Bones
of the Lower Extremities (Label bones in your notes !) Slide 110
Skeletal Differences in Men & Women Male Female Slide 111
Skeletal Differences in Men & Women Slide 112 Bones of the
Appendicular Skeleton Bones of the Lower Extremities Femur Bone
Thigh bone Longest, largest, and strongest bone in the body Slide
113 Bones of the Appendicular Skeleton Bones of the Lower
Extremities Patella (2 Bones) Kneecap Slide 114 Bones of the
Appendicular Skeleton Bones of the Lower Extremities Tibia Fibula
The tibia and fibula are the bones of the lower leg Tibia shin bone
is larger, medial, and more superficial than the fibula Slide 115
Bones of the Appendicular Skeleton Bones of the Lower Extremities
Tarsal Bones (14 Bones, 7 in Each Foot) Bones that form the heel
and the posterior portion of the foot Slide 116 Bones of the
Appendicular Skeleton Bones of the Lower Extremities Metatarsals
(10 Bones, 5 in each foot) Bones that form the long portion of the
foot Slide 117 Bones of the Appendicular Skeleton Bones of the
Lower Extremities Phalanges (28 Bones, 14 in each foot) Bones of
the toes (3 in each toe except big toe; big toe has 2 bones)
