A&P 1 midterm (ch. 6,7,8,9)

Skeletal system functions

Support, storage of minerals and lipids, blood cell production, protection, and leverage

Sutural bones

Small, flat, oddly shaped bones found between flat bones of skull, borders are jigsaw-puzzle like

Irregular bones

Complex shapes w/ short flat, notched, or ridged surfaces (ex: vertebrae, pelvis bones)

Short bones

Bone is boxlike in appearance (ex: carpal bones)

Flat bones

Thin parallel surfaces found on roof of skull, ribs, shoulder blades

Long bones

Long and slender, located in arm, leg, fingers

Sesamoid bones

Usually small, round, and flat (ex: near joints of knees, hands)

What are types of bone markings (surface features)

Projections and openings/depressions

Projections

Where muscle, ligaments, and tendons attach

Openings/depressions

For passage of blood vessels and nerves

what are the main structures of a long bones

Diaphysis, epiphysis, and metaphysis

Diaphysis (shaft)

Wall of compact bone and central space called medullary cavity

epiphysis (wide part at each end)

Mostly spongy bone (trabecular bone)

Metaphysis

Where diaphysis and epiphysis meet (growth occurs)

Structure of flat bones

Spongy bone between 2 layers of compact bone (within cranium, layer of spongy bones called dipole)

Bone tissue

Dense, supportive connective tissue, contains specialized cells, and has a solid extracellular matrix w/ collagen fibers

What makes the matrix of bone dense?

calcium salts

What makes up 2/3 of bone mass

calcium phosphate

When calcium phosphate interacts w/ calcium hydroxide what does it form?

Crystals of hydroxyapatite

What’s 1/3 of bone mass made up of

collagen fibers

What happens if a bone is lacking a calcified matrix

It’s very flexible but looks normal

What are the types of bone cells

Osteogenic cells, osteoblasts, osteocytes, and osteoclasts

Osteogenic cells (osteoprogenitor cells)

Mesenchymal cells that divide and produces OSTEOBLASTS; located in inner cellular layer of periosteum and endosteum; assist in fracture repair

Osteoblasts

Immature cells that produce new bone matrix (bone formation) via osteogenesis (ossification); surround by bone matrix and become OSTEOCYTES

Osteoid

Matrix produced by osteoblasts not yet to become calcified

Osteocytes

Mature bone cells that do NOT divide and live in lacunae between matrix

What cytoplasmic extensions do osteocytes have that allows for exchange of nutrients wastes, and gases

Canaliculi

what are the major unctions of osteocytes

Maintain protein and mineral context of matrix and help repair damaged bones

Osteoclasts

large multinucleate cells that removes and absorbs bone matrix and secretes protein-digesting enzymes and acids

What’s important in homeostasis regarding osteoclasts

osteolysis

Osteon

Functional unit of compact bone

Central canal

contains blood vessels

Perforating canals

perpendicular (horizontal) to surface of bone and carries blood vessels deep into bone marrow

lamellae

layers of bone matrix

Concentric lamellae

Surround central canal

Interstitial lamellae

fill spaces between osteons

Circumferential lamellae

located at outer and inner bone surfaces

What does spongy bone lack that compact bone has

osteons

What does spongy bone’s matrix of open network form

trabeculae (lacks capillaries and venules)

Red bone marrow

fill spaces between trabeculae, forms blood cells, and contains blood vessels that supply nutrients to osteocytes by diffsuion

Yellow bone marrow

found in other sites of spongy bone and stores fat

trebeculae in epiphysis of femur transfer forces from pelvis to compact bone of femoral shaft is what kind of bone

Weight bearing bones

Periosteum

Membrane that covers outside of bones EXCEPT joint cavities; has outer fibrous layer and inner cellular layer; fibers INTERWOVEN with tendons

Perforating fibers

Fibers that become incorporated into bone tissue and increases strength of attachments

Functions of periosteum

isolates bone from surrounding tissues, provides route for blood vessels/nerves, and helps in bone growth/repair

Endosteum

Incomplete cellular layer that lines medullary cavity, active in bone growth/repair/remodeling, covers trabeculae of spongy bone lines central canals, and consists of flattened layers of osteogenic cells

What are the most important things in bone development

Ossification and calcification

ossification (osteogenesis)

bone formation

calcification

deposition of calcium salts during ossification

What are the forms of ossification

Endochondral and intramembranous

Endonchondral ossification

How most bones/libs form

Primary ossification center (in endochondral )

Develops inside hyaline cartilage and that cartilage is replaced by bone

Intramembranous ossification

forms flat bones or “dermal” bones (bones deposited in membrane that does NOT replace exists cartilage)

Interstitial growth

growth in length that develops secondary ossification center

Epiphyseal closure

Shows completion of epiphyseal growth

What reveals timing of endochondral ossification

epiphyseal cartilages

What remains after epiphyseal closure

epiphyseal line

Appositional growth

Growth in width that thickens and strengthens bones and layers of circumferential lamellae added to outer surface (deepest layers replaced by osteons)

During appositional growth, what bone cell removes bone matrix at inner surface of bone which enlarges medullary cavity

osteoclasts

Nutrient and artery vein

most bones have one of each and passes through nutrient foramina in diaphysis

Metaphysical vessels

Supply blood to epiphyseal cartilage where bone growth also occurs

Epiphyseal seals

supply nutrients to cavities of epiphysis

Periosteal vessels

Supply blood to superficial osteons and secondary ossification enters

Bone remodeling

recycles and renews bone matrix, involves osteocytes, osteoblasts, and osteoclasts

What are the effects of exercise on bone

Minerał recycling allows bone to adapt to stress (bones become thicker and stronger) and weight-bearing exercise stimulates OSTEOBLASTS

What minerals are needed for bone development

Calcium and phosphorus required in diet

What’s crucial for bone development

Calcitriol (made in kidneys) and Vitamin D3

What vitamin is required for collagen synthesis

Vitamin C

What vitamin stimulates osteoblast activity

Vitamin A

What hormones maintain calcium ion homeostasis

Parathyroid and calcitonin

What does the parathyroid hormone do

It INCREASES blood calcium ion levels when they’re too low

What does calcitonin do

it DECREASES blood calcium ion levels when they’re too high

What makes up the axial skeleton

The skull, thoracic cage, and vertebrae column

Functions of axial skeleton

Supports/protects organs in body cavities, provides points of attachment for muscles

Functions of sinuses

Decreases weight of the skull, produces mucus to moisten and clean the air and helps w/ speech production

Functions of occipital bone

Forms much of posterior and inferior surfaces of cranium

Functions of parietal bones

forms superior and lateral surfaces of cranium

Functions of frontal bones

forms anterior part of cranium and roof of eye sockets

Functions of temporal bones

articulates w/ mandible, surrounds and protect internal ear, and attach muscles of jaws to head

What are the auditory ossicles in the tympanic cavity (middle ear) called

Malleus, incus, and stapes

Functions of sphenoid bone

forms part of floor of cranium, unites cranial/facial bones, and strengthens side of the skull

Functions of Ethmoid bone

forms anteromedial floor of cranium, roof of nasal canal, and part of nasal septum/medial orbital wall

What are the facial bones

Maxilla, palatine bones, nasal bones, vomer, inferior nasal conchae, zygomatic bones, lacrimal bones, mandible, and hyoid bone

functions of maxilla

Supports upper teeth, forms inferior orbital rims, lateral margins of external nares, upper jaw and hard palate and contains maxillary sinuses

functions of palatine bones

forms posterior portions of hard palate and contribute to floors of the orbits

function of nasal bones

support bridge of nose and connects cartilages of distal parts of nose that extend to external nares

functions of vomer

forms inferior portion of bony nasal septum

functions of inferior nasal concha

slow inhaled air, creates air turbulence in nasal cavity, and increases epithelial surface area to warm and humidify inhaled air

function of zygomatic bones

contribute to rims and lateral walls of orbits and forms zygomatic arches

functions of lacrimal bones

smallest facial bones that form parts of medial walls of orbits

functions of hyoid bone

supports larynx and attaches muscles of larynx, pharynx, and tongue

What are the bones that for the orbital complex for each orbit “Fast Male Lions Eat Poor Slow Zebras”

Frontal bone, maxilla, lacrimal bone, ethmoid, palatine bone, sphenoid, and zygomatic

functions Vertebral column

protects spinal cord, supports skull, weight of head, neck and trunk, transfers weight to lower limbs, and helps maintain upright position of body

Cervical has how many vertebrae

7

Thoracic has how many vertebrae

12

Lumbar has how many vertebrae

5

Each vertebrae has what

vertebral body, arch, and articular processes

Vertebral body

transfers weight along spine and forms anterior margin of each vertebral foramen

vertebral arch

walls are called pedicles and laminae form roof

Articular processes

lateral projection between laminae and pedicles