Skeletal System Flashcards
What are the 2 main components of bone?
- Inorganic
2. Organic
What inorganic components are in bone?
Minerals
What organic components are in bone?
Collagen
Minerals produce ____ in bones.
Hardness
Collagen provides the bone with _____ and _____.
Flexibility and Tensile Strength
What are the five functions of bones?
- Support
- Protection
- Movement
- Storage
- Blood Cell Formation
What do the bones store?
Fat, minerals (calcium and phosphorus)
What is blood cell formation called?
Hemo / hematopoiesis (in red bone marrow)
Two classification by nature of bone…
Compact and Spongy
Two classification by size of bone…
Long and Short
Two classification by shape of bone…
Flat and Irregular
This type of bone is hard and dense: ___
Compact
This type of bone as a smooth, homogeneous (uniform) appearance: ___
Compact
Compact bone occurs where most often?
Outer shaft of the long bones and outer layer of other bones
Spongy bone is made up of ___.
Trabeculae
What is trabeculae?
Meshwork of slender strands / plates / spicules of bone surrounded with lost of open cavities.
Spongy bone occurs most often…
Within ends of long bone and center of other bones
What is the main tissue bones made up of?
Osseous
Long bones are _____ than they are ____.
Longer; wide
Long bones have a ____ on both ends?
Semi-rounded head
The exterior of long bones are made up of what?
Compact bone
The interior of long bones are made up of what?
Spongy bone (most evident at the end of bones)
What is an example of long bones?
Limbs; arms and legs
Small round or cube shaped bones are classified as what?
Short bones
Short bones are composed mostly of what type of bone?
Spongy bone; have thin covering of compact bone
What is an example of short bones?
Wrist and ankle bones
What is the unusual subtype of short bones?
Sesamoid bones
Sesamoid bones can be found where?
Embedded in tendons adjacent to joints
Thin, flattened and usually curve bones are classified as what shape?
Flat
Flat bones are comprised of what?
Two layers of compact bone sandwiching spongy bone
What is an example of flat bones?
Skull, ribs, sternum
Bones that don’t fit into otherwise mention categories are called what?
Irregular bones
Examples of irregular bones are…
Vertebrae, hip bones, some facial bones
Long bones have two parts…
Diaphysis and Epiphyses
The diaphysis of a long bone is what?
The main shaft
The diaphysis is…
Compact bone surrounding internal opening, medullary cavity
The diaphysis is comprised of…
Periosteum
Describe Periosteum tissue
Tough, outer, vascular, fibrous connective tissue covering in the bone
Describe the epiphyses of the long bone
Irregular, frequently semi-rounded ends
Articular… Also means ____
Joints
What type of cartilage covers ends of bones at joint interfaces to reduce friction?
Articular cartilage; made of hyaline cartilage
The fundamental structural unit of bone consisting of a group of concentric solid tubes or rings is called what?
Osteon or Haversian system
What is at the center of lamella?
Central canal
Concentric layers of bone matrix are called what?
Lamellae
Each osteon runs ____ to the long axis of the bone.
Parallel
Patron running parallel gives the bone what?
Strength
What are the four structural components of osteon?
- Central canal
- Preforating canals
- Lacuna
- Canaliculi
Large canals running at right angles to the central canals
Preforating canals
Tiny spaces at interfaces between Lamellae of bone
Lacuna
Each lacuna contains a spider shaped ____
Osteocyte
Little canals radiating out from the central canals to connect to osteocytes in the lacunae
Canaliculi
Spongy bone contains fewer and less regularly arranged _____ than compact bone
Lamellae
Spongy bone is not organized into what?
Osteons
Red bone marrow serves what purpose?
Blood cell formation
Red bone marrow fill in spaces of bone?
Spongy bone; in the diaphysis
What changes of bone marrow between infants and adults?
Adults have yellow bone marrow within the diaphysis of the long bone
Yellow bone marrow serves what purpose?
Adipose tissue storage
When an adult, red bone marrow is made where?
Spongy bone a flat bones and the epiphyses of some long bones
What are the two forms of bone formation during development?
Intramembranous bone and Endochondrous bone
What is the process of forming endochondrous bone?
Embryonic memenchyme -> Hyaline cartilage template -> replaced by endochondrous bone
Gradual hardening of the intramembranous bone occurs when?
Infancy to childhood
Cartilage replaced by bone
Ossification
Cartilage remains where?
Bridge of nose, parts of ribs, joints,
Bone growth stops at what age?
Early 20s
What two hormones control bone development?
Growth and sex
Growth hormones play what part in bone development?
Stimulate cartilage cell division
Sex hormones play what part in bone development?
Stimulate ossification of epiphyseal plates
What are signs of bones aging?
Metabolism slows down
Resorption; loss of bone mass
Decrease collagen framework
Weaker, more fragile bones
____ form and secrete bone matrix around themselves
Osteoblasts
Mature bone cells
Osteocytes
Bone break down - resorption
Osteoclasts
What are the two primary subdivisions of a skeleton?
Axial and appendicular
The axial skeleton contains what part of the body?
Skull, vertebral column, rib cage
The appendicular skeleton contains what part of the body?
Limbs, Girdles
Not just bones - joints, cartilages, ligaments
How many bones are in the axial skeleton?
80
How many bones are in the appendicular skeleton?
126
