LECTURE 7 Flashcards
Why is it that a particular bone, such as the humerus, is considered to be an organ?
They consist of multiple tissue types that are working for the same general purpose.
List and briefly describe four of the many components of the skeletal system.
- 206 bones
- Three types of cartilage
- Ligaments (bone to bone)
- red & yellow bone marrow
- Blood and nervous tissue
3 types of cartilage in the body
hyaline cartilage
elastic cartilage
fibrocartilage
Functions of the skeletal system
- Support: Of muscles, teeth, and body as a whole
- Mineral/energy storage, and ion balance: Calcium and phosphate. Yellow bone marrow has lipids to store energy.
- Hemopoiesis: Aka hematopoiesis. Blood cell production in red marrow.
- Protection: cranial bones protect the brain, vertebral column protects the spinal cord. Protects CNS, thoracic and pelvic viscera, and bone marrow.
- Locomotion: Skeletal muscles act on bones allowing for movement around articulations.
Name the two ways that the bones of the body are classified.
- structure/shape
- internal composition (compact/spongy)
Longer than wide. Shaft and two ends. Most important for movement.
(femur, humerus, radius, ulna, tibia, fibula)
long bones
Roughly cube-shaped
(wrist in carpals, ankle in tarsals)
short bones
Thin, flat, and often curved
(sternum, scapulae, ribs, hip, and skull bones)
flat bones
Found between sutures of skull bones. Small, numerous, and irregularly shaped. Not included in the 206 bones.
(coronal, sagittal, squamous, lambdoid sutures)
sutural bones
Complex shapes with processes. Vertebrae, ethmoid bone (separates the nasal cavity from the brain), and sphenoid bone from the skull.
irregular bones
Small bones formed in tendons. In the shape of a sesame seed.
Patellas- largest sesamoid bones, and only ones included in 206 bones
sesamoid bones
Shaft of the long bone. Walls made of compact bone (dense bone)
diaphysis
The head of the long bone. Distal and proximal ends. Wall is compact and the interior is spongy bone. Red marrow found in spongy bone.
Articular cartilages (hyaline that lack perichondrium) cover articular surfaces of epiphyses.
epiphyses
-a hollow space to the interior of diaphysis
-Yellow marrow found here. Was red marrow as a child. Can revert back to red marrow in severe anemia to produce more red blood cells
-Tiny amount of spongy (cancellous) bone close to medullary cavity
medullary cavity
“growth plate” made of hyaline cartilage
epiphyseal plate
very dense spongy bone, used to be an epiphyseal plate
epiphyseal line
Describe the distribution of both compact and spongy bone in a typical long bone.
Compact bone lines the entire outer surface
Spongy bone within, especially in the epiphysis.
There is a little lining of spongy bone within the diaphysis around the medullary cavity.
Describe the distribution of both yellow and red bone marrow in a typical long bone
(Describe the composition and functions)
RED BONE MARROW
-typically found in the proximal epiphysis.
-reticular connective tissue
-produces blood.
YELLOW BONE MARROW
-in the medullary cavity and distal epiphysis
-adipose tissue
-energy storage
Describe the make-up of a typical flat bone
2 layers of compact bone. Outer compact bone, spongy bone (diploe), inner compact bone
Why is it difficult to completely break through one of the flat bones of the skull?
because the outer bone may take initial force and crack, but the diploe is excellent at dispersing the force of an impact, so that the interior compact bone is typically left intact.
outer surface of compact bone
periosteum
structure of a periosteum
White collagenous fibers. Blood vessels are prominent in the periosteum and enter matrix through nutrient foramina to allow for exchange of materials. Lymph vessels and nerves present in bone travel through the periosteum and enter bone.
periosteum layers and cell types
Outer fibrous layer of dense irregular connective tissue. Perforating fibers from the outer layer enter the bone matrix to have a solid connection to the bone.
Inner cellular layer that has 3 of the 4 cell types. Those cell types include: osteogenic (osteoprogenitor) cells, osteoblasts, and osteoclasts.
You do NOT find the osteocytes in the periosteum.
functions of periosteum
Outer layer serves as an attachment for tendons and ligaments. Inner layer allows for remodeling and healing of fractures. Inner layer makes a bone matrix or breaks it down.