BIOL 2262 Exam 2

Step 1 of Endochondral Ossification and Epiphyseal Bone Growth

small blood vessels infiltrate the outer layer of hyaline cartilage

Step 2 of Endochondral Ossification and Epiphyseal Bone Growth

hyaline cartilage becomes vascularized periosteum

Step 3 of Endochondral Ossification and Epiphyseal Bone Growth

osteogenic cells differentiate into osteoblasts cells differentiate into osteoblasts

Step 4 of Endochondral Ossification and Epiphyseal Bone Growth

bone collar around the diaphysis is formed

Step 5 of Endochondral Ossification and Epiphyseal Bone Growth

ossification begins in the center of the diaphysis, primary ossification center

Step 6 of Endochondral Ossification and Epiphyseal Bone Growth

periosteal bud invades

Step 7 of Endochondral Ossification and Epiphyseal Bone Growth

osteoclasts delivered to the primary ossification center begin to erode calcified cartilage

Step 8 of Endochondral Ossification and Epiphyseal Bone Growth

as more diaphysis becomes bone, osteoclasts break it down to elongate the medullary cavity

Step 9 of Endochondral Ossification and Epiphyseal Bone Growth

birth of the baby

Step 10 of Endochondral Ossification and Epiphyseal Bone Growth

secondary ossification centers appear

Step 11 of Endochondral Ossification and Epiphyseal Bone Growth

epiphyseal plates begin to enlarge as chondrocytes rapidly divide

Step 12 of Endochondral Ossification and Epiphyseal Bone Growth

as epiphyseal plates enlarge and grow away from the diaphysis, old chondrocytes ossify

Step 13 of Endochondral Ossification and Epiphyseal Bone Growth

osteoclasts erode epiphyseal bone to make spongy bone in each epiphysis

Step 15 of Endochondral Ossification and Epiphyseal Bone Growth

by puberty the diaphysis is complete in length and width and epiphyses are mostly spongy bone with a compact bone epiphyseal line

What are the tree-ring pattern seen in compact bone?

osteons

What allows osteocytes to communicate and exchange nutrients and waste?

canaliculi

T or F:

Osteopenia can progress into osteoporosis

Harvesian canal

found in the center of each osteon and houses blood vessels and nerves

Lamellae

lacunae that are arranged in concentric circles

From birth to late adolescence, _______ activity exceeds ________ activity

osteoblast; osteoclast

In a typical adult, _______ activity is equal to ________ activity.

osteoblast; osteoclast

Spongy bone is replaced every….

3-4 years

Compact bone is replaced every….

10 years

Functions of the skeletal system

protection of internal organs, production of osteocalcin, triglyceride storage

Which type of ossification forms the cranial bones, clavicles, and other flat bones?

intramembranous ossification

Describe appositional growth in cartilage

it occurs at the outer surface where chondroblasts from the perichondrium add new matrix, increasing thickness

Describe interstitial growth in cartilage

existing chondrocytes divide and produce new matrix within, leading to cartilage lengthening

What is the primary role of collagen fibers in bone tissue?

to give bone shape and tensile strength through sacrificial bonds

What is the inorganic component of bone that makes it hard and durable?

hydroxyapatite

Wolff’s Law and bone remodeling

Bones remodel and become thicker in response to increased mechanical stress, such as in the dominant arm of a right-handed person

What hormone is released when blood calcium levels are too low, and what is its main effect?

PTH; increases osteoclast activity to raise blood calcium

Periosteum

Protective covering surrounding the bone; contains many blood vessels and nerves

Diaphysis

shaft of the bone; composed mainly of compact bone

Epiphyses

Ends of the bone; contains spongy bone with red marrow among trabeculae

Articular cartilage

Covers the end of bones at joints; made of hyaline cartilage

Endosteum

Vascularized connective tissue lining the medullary cavity

Medullary cavity

Open space inside the diaphysis; contains yellow marrow

Osteocytes

Mature bone cells that maintain the bone matrix

Osteoclasts

Bone-resorbing cells that break down bone tissue using enzymes

Osteogenic cells

Bone stem cells that can differentiate into osteoblasts

Osteoblasts

Bone-building cells that secrete collagen and calcium-binding proteins

Greenstick fracture

bone breaks incompletely; like a twig

Comminuted fracture

bone is crushed into three or more pieces

Spiral fracture

bone is twisted apart due to torque

Epiphyseal fracture

break occurs at the growth plate

Compression

bone is crushed; common in vertebrae

Osteopenia

age-related bone loss, occurs gradually after age 30

Paget’s Disease

bone is built and resorbed in an unbalanced fashion

Osteoporosis

bone density as PTH is released from bone tissue; vertebrae compression and comminuted hip fracture are the most common injuries

Rickets

bone calcium level is low; typically caused by Vitamin D deficiencies

What are sinuses lined with to help warm and moisten the air we breathe?

Mucosa

During fetal development, is the sacrum and coccyx fused or not?

Not fused

What bone is an attachment site for many muscles?

Ilium

What surrounds tendons?

Tendon sheaths

The paranasal sinuses are open spaces inside what skull bones?

Frontal, ethmoid, sphenoid, and maxilla

What ribs are considered floating ribs and why are they called that?

11 and 12; they do not attach to the sternum at all

True ribs

directly attached to the sternum by their own costal cartilage

An exaggerated thoracic curvature

Kyphosis

How many bones are in the appendicular skeleton?

126

What are the functions of the facial bones?

Give structure to the face, anchor facial muscles and teeth, and contain cavities for special senses

Characteristic of the pectoral (shoulder) girdle.

High mobility = decreased stability

Which bones make up the os coxae in the pelvic girdle

Ilium, ischium, and pubis

What does the pelvic girdle include?

Os coxae and the sacrum and coccyx

Describe the difference between the male and female pelvic girdle

Female pelvis has a wider pelvic opening and a U-shaped pubic arch

What type of fibrous joint is located between the radius and ulna AND tibia and fibula?

Syndesmoses

Function of synovial fluid

Shock absorption, lubrication, nutrients for chondrocytes, protects articular cartilages

Describe the articular capsule in a synovial joint

Includes a fibrous capsule that holds bones together and a synovial membrane that produced synovial fluid

Which type of movement involves two bones sliding past each other at flat boney surfaces?

Gliding

Functions of the cranial bones?

Protect the brain, attach neck muscles, and contain sinuses for resonation and air conditioning

Hinge Joint Classification

uniaxial

Hinge Joint Examples

elbow, knee, ankle, & interphalangeal

Plane Joint Classification

non-axial

Plane Joint Examples

intercarpal, intervertebral

Pivot Joint Classification

uniaxial

Pivot Joint Examples

proximal radioulnar, atlantoaxial (between atlas & axis)

Condylar Joint Classification

biaxial

Condylar Joint Examples

metacarpophalangeal, radiocarpal

Saddle Joint Classification

biaxial

Saddle Joint Examples

carpometacarpal joint of the thumb

Ball and Socket Joint Classification

multiaxial

Ball and Socket Joint Examples

shoulder and hip

Supination

rotating the hand laterally

Flexion

the angle between bones decreases (they move closer together)

Plantarflexion

the toes press downward

Extension

moving a structure toward the midline of the body

Dorsiflexion

the toes pull upward

Hyperextension

a bone extends beyond the anatomical position

Inversion

the foot rolls medially

Abduction

moving a structure toward the midline of the body

Eversion

the foot rolls laterally

Adduction

moving a structure toward the midline of the body

Protraction

a structure moves forward

Medial rotation

the bone turns toward the midline of the body

Retraction

a structure moves backward

Lateral Rotation

the bone turn away from the midline of the body

Elevation

a structure moves up

Depression

a structure moves down

Pronation

rotating the hand medially

Rhematoid arthritis

autoimmune form of arthritis where white blood cells release inflammatory chemicals

Tendonitis

inflammation and swelling of a tendon or a tendon sheath caused by injury or overuse