Antatomy Exam 2

components of axial skeleton

skull, spine , thoracic cavity

components of appendicular skeleton

limbs, pectoral girdle, pelvic girdle

Components of skeletal system

axial, appendicular, cartilage, and ligaments

Purpose of skeletal system

support- attachment of other organs

movement/ locomotion- muscles use bones as levers

storage of minerals- Ca and PO4 ions

blood cell production- Erythrocytes leukcytes and platelets

protection- ex on next slide

examples of skeleton protecting organs

ribs protecting heart and lungs

Skull protects brain

Vertebrae protects spinal cord

Pelvic bones protect reproductive organs

What does the bone matrix consists of?

hydroxyapatite crystals; mainly CaPo4

2/3 of bone mass is CaPO4

1/3 is collagen fibers

2% of bone mass is bone cells

what does collagen contribute to bones

tensile strength and limited flexibility

osteocytes

maintain matrix, controls Ca composition in and out of bone, have lacunae, lamella and canaliculi

osteoblasts

produces matrix of bone- immature bone cells

found on inner and outer surfaces of bones

perform osteogenesis

produce osteoid

osteoprogenitor

produce osteoblasts (bone stem cells)

inner most later of periosteum and inner lining of endosteum

helps with repair of bone after fracture

osteoclasts

break down matrix- multinucleated cells, that secrete HCl for osteolysis releasing Ca and PO4 into blood

what is osteoid

organic mix dumped into the matrix of bones

what is osteogenesis

a new bone formation via calcification of osteoid leading to ossification

lacunae

depression where osteocytes reside

Lamella

osteocyte matrix

canaliculi

small channels from osteocytes to bone capillaries

Compact bone

dense bone that forms wall of bone and have parallel compression,

spongey bone

trabecular bone that is multidirectional and a network of plates

epiphysis

ends of long bones

diaphysis

shaft of long bones

metaphysis

transition

medullary cavity

inner cavity of diaphysis

epiphyseal line

growth line

yellow marrow

mainly adipose, energy storage and found in medullary cavity

Red marrow

production and storage of leukocytes, erythrocytes and thrombocytes found in epiphysis or spaces between trabeculae

functions of periosteum

isolates and protects bone from surrounding tissue

attachment for circulatory and nervous supply and tendons/ligaments

bone growth/repair

endosteum

single incomplete cell layer that lines medullary cavity, perforating canals and central canals

what cells do both the endosteum and periosteum contain

osteoblast: produce matrix

osteoprogenitor: produce osteoblasts

Appositional growth

increase in size of medullary cavity or diameter of bones by adding circumferential lamellae on outer surface

what causes appositional growth

stress from increased muscle activity or weight

by what age is the length of bones typically set

25

what two bone cell types have equal activity in bones that are not changing

osteoblast and osteoclast

What are two factors that change the shape of bones

incr muscular developement

degeneration- after a few weeks bones can loose 1/3 of mass; shape and density

what are factors that regulate bone growth

Minerals: ca, Po4, Mg, citrate, Co3, Na

Vitamins: A,C,D3

Hormones: parathyroid (PTH) ,Calcitonin, thyroxin, growth hormone, estrogen and testosterone

what does vitamin A do for bones

stimulate osteoblasts

what does vitamin C do for bones

stimulate collagen formation and osteoblast differentiation

what does vitamin D3 do for bones

used for calcitroil by kidneys which inc Ca and PO4 absorption in small intestine

how to hormones effect bone growth

they work to regulate plasma Ca levels

how does parathyroid (PTH) affect bone growth

stimulates osteoclast which incr circulating Ca and influences production of calcitroil in kidneys

how does calcitonin affect bone growth

inhibits osteoclasts which decreases circulating Ca so Ca is removed from blood and is deposited as bone

how does thyroxin and growth hormone affect bone growth

influences basal metabolic rate of bone cells, and maintains activity in epiphyseal region for growth

how do estrogen and testosterone effect bone growth

stimulate osteoblast activity causing growth spurts, and helps maintain bone density in adults

types of bones

sutural, pneumatized, short, irregular , flat , long , sesamoid

sutural bone w example

small odd shaped bones found between flat bones of skill along the suture line.

Pneumatized bone w example

hollow or contain numerous air pockets

ex ethmoid

short bone w example

boxlike structures that have both compact and spongey bone

ex carpals and tarsals

irregular bone w example

complex shapes w short or flat notched or ridged surfaces

ex vertebrae and several skull bones

flat bone w example

have thin, parallel surfaces of compact bone with spongey in between; light but strong to protect underlying soft tissues

ex: parietal, sternum, ribs, scapule

long bone w examples

long and slender; have diaphysis, two metaphyses, two epihyses and medullary cavity

ex: humerus, radius, ulna, femur, tibia and fibula

sesamoid

small round and flat, develope insdie tendons

ex; patella

the axial skeleton houses what nervous system?

the central nervous system

purpose of CNS

intregration center for reflex arcs, and control of skeletal muscle, houses senses , sound production/communiation, feeding, breathing

components of thoracic cage

ribs, sternum, thoracic vertebrae, costal cartilage

suture

dense fibrous connective tissue

what are fontanelles

gaps between cranial sutures that give flexibility to skull during parturition (child birth)

bones that make up the orbit of the skull

frontal, maxilla, lacrimal, ethmoid, sphenoid, zygomatic

ethmoid bone and its structure

Little holes on cribriform allow molecules to move through sinuses, and process smells

infraorbital foramen

important for blood vessels and nerves

why is the hard palate important

it separates oral and cranial cavity (formed by palatine)

parts of mandible

two separate bones fused together (dentary left and right)

Condylar process function

forms mandibular joint

Mandibular foramen importance

blood vessel and nervous system passageways

Sinuses purpose

produce mucus

resonate sound

lighten skull

humidifies air - makes air warm and moist for lungs

lined w epithelial cells

hyoid purpose

anchor point for muscles of tongue and larynx

only bone that does not articulate w other bones

purpose of vertebral column

support/ protect spinal cord

all mammals have 7 cervical vertbrae besides sloths and manatee

Vertebral foramen function

passageway for spinal cord

Cervical and lumbar vertebrae have...

superior and inferior articular facets

Thoracic vertebrae have...

Costal facets as well and superior and anterior bc they form ribs

what do only cervical vertebrae have? and what is its function

transverse foramen, which is the passageway for cranial nerves

Atlas function

only vertebrae that doesn't have prominent body, allows for "yes movement of head"

axis

allows for "no" movement of head, has dens

what are costal faucets

articulation points for ribs found on the thoracic vertebrae

sacrum function

articulation point for coxal bones

sacral foramina

passage way for spinal nerves

true ribs

1-7, have own individual costal cartilage

false ribs

8-12, share coastal cartilage (not fused)

floating ribs only...

11 and 12 attache to the spine not the sternum

what is the appendicular skeleton and its components

comprised of the upper and lower extremeites which include the shoulder girdle and pelvis

what is the only direct connection between the pectoral girdle and axial skeleton

the sternoclavicular joint

what is the pectoral girdle comprised of

clavicle and scapula

sternocalvicular joint

sternal end of clavicle connects to sternum

what is the articulation point for the humerus

the glenoid cavity

what kind of joint is in the glenoid cavity

ball and socket joint

what is the Interosseous membrane

space between radius and ulna,

why is tubercle of humerus important

attachment points for ligaments and tendons

Trochlea articulates w...

the ulna

Capitate articulates w...

the radius

Epicondyles are important for

attachment for ligaments

Anatomical neck of humerus

separates head from rest of bone

the surgical head of the humerus

separates the entire the entire epiphysis from the bone

another term for the forearm is

Antebrachium

what do the carpals form?

the palm of the hand

what is the pelvic girdle and what is it comprised of

the second articulation point between the axial and appendicular skeleton, made of coxal and sacrum

what three bones form the coxal

illim, pubis and ischium

importance of obturator foramen

nerve and blood vessels run through them

importance of acetabulum

where femur head inserts to form ball and socket joint

Auricular surface of coxal is important for

attachement to sacrum

what is the largest seesmoid bone

patella

sacro-iliac joint

the only direct connection between the pelvic girdle and the axial skeleton

interosseous membrane

space between tibia and fibula