anatomy ch.6 over the skeletal system

what are the 4 structures that make up the skeletal system?

bones, cartilage, ligaments, other supportive connective tissues

what are 4 main functions of the skeletal system?

framework for body, supports body weight, stores nutrients (CA2+ and posphorus), attachment to muscles for movement

describe the extracellular matrix of cartilage, and how it resists stress and has flexibility compared to bone

semirigid extracellular matrix. cannot resist stress like bone, but is more flexible and resilient than bone

what are the two types of cartilage cells? describe them. what is lacunae?

Chondroblasts: immature cells that produce new cartilage cells. Chondrocytes: mature cartilage cells, occupy small spaces called lacunae

is mature cartilage avascular and what effect on nutrient diffusion does that have?

yes, mature cartilage is avascular, which makes nutrient diffusion very difficult

what are the 3 types of cartilage, describe them, where they are located, and their function?

Hyaline cartilage: glossy cartilage that covers the ends of long bones, prevents friction.

Fibrocartilage: stronger more resilient cartilage, found in between intervertebral discs, built to withstand stress and pressure

Elastic Cartilage: weaker cartilage that is very flexible, found in nose and ear lobes, provides flexibility

what are the 3 main functions of cartilage?

1. support soft tissues like respiratory system and ear

2. provide gliding surface at articulations

3. precursor for bone growth (cartilage to bone)

what are the two cartilage growth patterns and define them

1. Interstitial growth: hyperplasia in the middle of tissue

2. appositional growth: hyperplasia on edge of tissue

how many tissue types do bones contain and describe a bone’s extracellular matrix and the reason for it

they contain all 4 tissue types. bones have a firm and rigid texture because of calcification (deposition of minerals)

what are the 5 general functions of bones?

1. provide structural framework

2. protect internal organs

3. allow movement- site of muscle bonding

4. hematopoiesis- blood cell production within red bone marrow

5. storage of minerals- Ca2+, phosphate (ATP production), lipids (stored in yellow bone marrow)

what are the 4 types of bones? describe them and provide an example of each.

1. long bones: elongated shafts (femur)

2. short bones: as long as they are wide (torsal)

3. flat bones: broad and thin (frontal bone)

4. irregular bones: catch-all for weirdly shaped bones (vertebrae)

what are the three regions of long bones? which region is the growth plate located in?

1. diaphysis: shaft and majority of the bone

2. metaphysis: area between diaphysis and epiphysis. contains growth plate.

3. epiphysis: end of the long bone

describe the general blood supply and innervation of bones. what is the area where blood vessels and nerves enter called and what are the primary nerves entering?

bones are highly vascularized in order to access the nutrients. the nutrient foramen is the hole where blood vessels and nerves enter (primarily sensory nerves)

what are osteoprogenitor cells and where are they found?

stem cells found in the endosteum and periosteum

what do osteoblasts dp, what do they secrete and what purpose does it serve?

they build bone and secret osteoid, which forms bone matrix

what are osteocytes, what is their job, and how are they made?

mature bone cells, they maintain the matrix and detect stress on the bone. they are made when osteoblasts get trapped by the bone matrix

what is the job of osteoclasts, what do they release, and what does the body use it for?

they dissolve bone matrix which releases Ca2+ which is used as the body’s backup source