the skeletal system is strong, light, adapted for protection,
and adapted for motion axial longitudinal axis appendicular limbs
and girdles also includes joints, cartilages, and ligaments
Slide 3
functions support internal framework, supports/anchors all soft
organs protection protect by surrounding softer body organs
movement skeletal muscle attach to bones via tendons and are used
as levers to move storage fat is found in internal cavities, Ca and
P in bone tissue blood cell formation (hematopoiesis) in marrow of
some bones
Slide 4
types compact bone dense and smooth spongy bone small
needle-like pieces with open spaces
Slide 5
Slide 6
classification the shape of each bone determines its function
long bones longer than they are wide shaft with a head at each end
mostly compact all limb bones except metacarpals and metatarsals
short bones generally cube shaped mostly spongy metacarpals and
metatarsals
Slide 7
Slide 8
flat bones thin, flat, and curved 2 thin layers of compact bone
with a layer of spongy bone in between skull, ribs, sternum
irregular bones do not fit any other category vertebrae and hips
bone markings are where muscles/tendons/ligaments attach and where
blood vessels/nerves pass
Slide 9
Slide 10
structure of a long bone diaphysis the shaft mostly compact
bone covered with periosteum epiphyses the ends of the long bones
thin layer of compact bone surrounding spongy bone covered with
cartilage to decrease friction yellow marrow (medullary) cavity
storage area of fat tissue in adults contains red marrow in infants
that make RBCs
Slide 11
Slide 12
microscopic anatomy mature bone cells (osteocytes) are found in
cavities (lacunae) and secrete a solid matrix lacunae are arranged
in a circle (lamella) around a central canals (osteonic canal)
several lamella (lamellae) surrounding a single central canal is an
osteon canals run lengthwise thru the bone to carry blood vessels
and nerves from end to end tiny canals (canaliculi) run
horizontally to connect all lacunae allows all osteocytes to be
well supplied with nutrients even though the matrix is solid larger
canals (perforating) run horizontally between the osteons
Slide 13
bone formation, growth, and remodeling the skeleton is formed
from bone and cartilage 2 of the strongest tissues in the body
babies have cartilage that is gradually replaced by bone
(ossification) cartilage contains osteoblasts which secretes bone
matrix bone matrix replaces cartilage matrix osteocytes replace
chondrocytes cartilage becomes bone process is continually repeated
result is bone growth to lengthen long bones growth hormone starts
the process and sex hormones continue growth during puberty
cartilage only remains in ears, nose, ends of ribs, and joints
Slide 14
bones are continually remodeled to release Ca into the blood Ca
levels drop below homeostatic levels parathyroid glands release
hormone to activate bone-destroying cells (osteoclasts) bone matrix
is broken down to release Ca into the blood to remove Ca from the
blood blood Ca levels that are too high cause hypercalcemia Ca is
removed from the blood and deposited into bone matrix to retain
normal proportions during growth bones become thicker with age
bones form larger projections in response to bulkier muscles
osteoblasts lay down new matrix, become trapped, and become
osteocytes
Slide 15
Bone Fractures in youth, most fractures/breaks occur from
trauma that twists or smashes bones in older adults, bones
thin/weaken so fractures are more common fractures are set by
reduction and immobilization closed reduction is by external
manipulation open reduction is by surgery and requires bone to be
pinned/wired hematoma forms where the bone breaks cartilage callus
is replaced by osteoblasts and osteocytes to form a spongy bony
callus bony callus continually remodeled and strengthened into a
permanent patch
Slide 16
Slide 17
Explain how this picture makes you feel and describe it using
vocabulary you have learned about bones, tissues and
integument.
Slide 18
Axial Skeleton forms the longitudinal axis (skull, vertebral
column, bony thorax) skull cranium encloses/protects brain frontal
bone forehead/brows/superior orbit parietal bones superior and
lateral cranium temporal bones inferior to parietal external
auditory meatus ear canal styloid process needle-like projection
for neck muscle attachments zygomatic process bridge that joins
with zygomatic bone to form cheekbones mastoid process contains air
cavities and provides attachment site for neck muscles jugular
foramen allows for passage of jugular vein carotid canal allows for
passage of carotid arteries
Slide 19
occipital bone floor and back wall of skull foramen magnum
passage of spinal cord to the brain occipital condyles rests the
skull on the first vertebra sphenoid part of the floor of cranial
cavity, part of the orbit ethmoid bone irregular and anterior to
sphenoid, forms roof of nasal cavity and medial orbit
Slide 20
Slide 21
facial bones holds the eyes in position attached to each other
with sutures (except mandible) maxillae fuse to form upper jaw,
carry teeth in alveolar margin palatine process hard palate
zygomatic bones lateral orbits, connect with temporal bones to form
cheekbones lacrimal bones medial orbits, groove for tear ducts
nasal bones bridge of the nose vomer bone median line in the nasal
cavity that forms the septum inferior conchae thin curved bone
projecting into the nasal cavity mandible strongest bone of the
face, lower jaw
Slide 22
hyoid bone not a part of the skull be closely related to the
mandible and temporal bone only bone not articulated with another
bone suspended midneck above the larynx by attachments to the
styloid process serves as a movable base for the tongue and
attachment site for neck muscles fetal skull regions of skull are
not yet ossified and are connected by fibrous membranes (fontanels)
fontanels allow fetal brain to grow during late pregnancy and the
skull to compress during birth
Slide 23
Slide 24
vertebral column (spine) made of 26 irregular bones (reinforced
by ligaments), the sacrum, and coccyx separated and cushioned by
flexible intervertebral discs supports the skull and protects the
spine all have 6 common features: body weight-bearing part,
anterior side vertebral arch formed from the joining of all
extensions vertebral foramen spinal cord canal transverse processes
2 lateral projections spinous process posterior projection superior
articular processes projections allowing vertebra to articulate
(join) together
Slide 25
Slide 26
cervical vertebrae (C1-C7) 7 vertebrae in the neck region first
is the atlas (supports the skull and allows anterior/posterior
movements) second is the axis (allows lateral movements) remaining
5 are smallest and lightest all have transverse foramen for
vertebral arteries travelling to the brain
Slide 27
thoracic vertebrae(T1-T12) next 12 vertebrae from the most
superior rib to the most inferior rib designed to articulate with
the head of the ribs lumbar vertebrae (L1-L5) lower back massive
bodies to withstand heavy stresses
Slide 28
sacrum fusion of 5 vertebrae articulates with L5 (superior),
the coccyx (inferior), and the ilium (laterally) coccyx (tailbone)
fusion of 3 to 5 small vertebrae remnant of mammalian tails
Slide 29
Slide 30
bony thorax (thoracic cage) thoracic vertebrae 12 vertebrae
that articulates with the ribs sternum (breastbone) fusion of 3
bones (manubrium, body, and xiphoid process) contains hematopoietic
tissue
Slide 31
ribs 12 pairs that all articulate with the thoracic vertebrae
first 7 pairs are true ribs articulate with the sternum by costal
cartilage next 5 pairs are false ribs articulate indirectly to
sternum or not at all (last 2 pair lack articulation and are
floating ribs)
Slide 32
Slide 33
appendicular skeleton composed of 126 bones of the limbs the
pectoral and pelvic girdles (attach the limbs to the axial
skeleton)
Slide 34
pectoral girdle consists of two bones (clavicle, scapula) very
light and allows upper limb to have exceptionally free movement
attaches to the axial skeleton at only one point (sternoclavicular
joint) clavicle is a slender, doubly curved bone attaches to the
manubrium of the sternum medially and to the scapula laterally acts
as a brace to hold the thorax helps prevent shoulder
dislocation
Slide 35
scapula is triangular not directly attached to the axial
skeleton loosely held in place by trunk muscles glenoid cavity is a
shallow socket that receives the head of the arm bone (poorly
reinforced by ligaments) loose attachment of the scapula allows it
to slide back and forth against the thorax
Slide 36
Slide 37
bones of the upper limbs arm is formed by a single bone
(humerus) forearm is formed by two bones (radius and the ulna) (in
anatomical position, the radius is lateral and the ulna is medial)
hand consists of the carpals, the metacarpals, and the phalanges
(carpals form the wrist, metacarpals form the palm, phalanges forms
the fingers)
Slide 38
Slide 39
pelvic girdle is formed by two coxal bones (hip bones) hip
bones, sacrum, and coccyx form the bony pelvis each hip bone is
formed by the fusion of three bones (ilium, ischium, and pubis)
ilium - large, flaring bone, forms most of the hip bone ischium -
the most inferior part, receives body weight when sitting pubis -
the most anterior part all fuse at a deep socket (acetabulum) that
receives the head of the femur
Slide 40
Slide 41
bones of the lower limbs carry total body weight when standing
bones are much thicker and stronger than the comparable bones of
the upper limb femur only bone in the thigh heaviest/strongest bone
in the body head articulates with the acetabulum neck is a common
fracture site slants medially as it turns downward (bring knees in
line with the body's center of gravity) tibia is larger, medial,
and the proximal end articulates with the distal femur to form the
knee fibula lies alongside the tibia, is thin, sticklike, and has
no part in forming the knee
Slide 42
Slide 43
foot is composed of tarsals, metatarsals, and phalanges tarsus
(ankle) supports body weight especially the calcaneus (heel) and
talus serves as a lever that propels the body forward when
walking/running bones are arranged to form three strong arches two
longitudinal (medial and lateral) and one transverse
ligaments/tendons hold bones firmly in the arched position but
allow movement
Slide 44
Slide 45
joints (articulations) with one exception (hyoid) every bone
forms a joint with at least one other bone two functions - hold the
bones together securely / give the rigid skeleton mobility
classified in two ways - functionally and structurally
Slide 46
functional - focuses on the amount of movement freely movable
joints (limbs) immovable / slightly movable joints (axial
skeleton)
Slide 47
structural - fibrous, cartilaginous, and synovial joints
fibrous immovable cartilaginous bone ends connected by cartilage
slightly movable (intevertebral joints) synovial surfaces enclosed
by a capsule of tissue and ligaments are freely movable more
flexibility than other joint types (flexibility varies
slightly)
Slide 48
Slide 49
Slide 50
Slide 51
inflammatory disorders of joints bursitis - inflammation of
bursae or synovial membrane sprain - ligaments / tendons are
damaged by excessive stretching or torn away from the bone
arthritis - over 100 different inflammatory or degenerative
diseases that damage the joints acute forms of arthritis usually
result from bacterial invasion (treated with antibiotics) chronic
forms of arthritis osteoarthritis - usually slow / irreversible,
rarely crippling rheumatoid arthritis - autoimmune disease,
cartilage is destroyed, scar tissue forms, bone ends connect, scar
tissue ossifies, bone ends become fused gouty arthritis - uric acid
accumulates in blood, may be deposited as crystals in the soft
tissues of a single joint