Unit 1 - Skeletal System Flashcards
How many bones do the human skeleton consist of?
The framework of the body is made up of 206 bones, associated cartilages and joints that form the human skeleton.
Define
Organ system
A group of organs and tissues working together to perform specific functions.
Which are the skeletal systems five primary functions?
Movement: Bones come together to form joints that allow motion.
Structure/support: The skeleton provides the structure and support we need for movement. This is one factor that separates humans from amoeba or jellyfish.
Protection: Our essential organs such as the brain, spinal cord, heart and lungs are protected by the skeleton.
Calcium storehouse: Calcium and other minerals are stored within bone.
Blood cell production: Marrow within bone produces blood.
The human skeletal system an be divided into which two structures?
Axial skeleton: The bones of the skull, vertebral column, sternum, ribcage and sacrum.
Appendicular skeleton: The bones of the upper and lower extremities.
How many bones are there in i axial skeleton?
80
How many bones are there in the appendicular skeleton?
126
The human vertebral column are divided into which regions? And how many vertebrae are there per region?
Cervical region: 7 vertebrae
Thoracic region: 12 vertebrae
Lumbar region: 5 vertebrae
Sacrum region: 5 vertebrae
Coccyx region: 4 fused vertebrae
How many vertebae dp the human vertebral column consist of?
33
How many - and which - vertebrae in the human vertebral column can move freely?
24, from the first cervical vertebrae to the last lumbar vertebrae.
Define
Ossification
The hardening process of bones during development.
Until which age do the hardening process (ossification) continue in the human development?
Until 18-25 years of age
Define
Epiphyseal plate
The location of bone growth near the end of immature bones.
Define
Epiphyseal line
A line of cartilage near the end of mature long bones.
Define
Stress fracture
A thin bone crack due to an accumulation of microdamage.
In the context of the human skeleton, define “Remodeling”
When a bone changes shape either by increasing or decreasing its diameter.
In the context of the human skeleton, define “Deposition”.
Adding new bone with osteoblasts.
In the context of the human skeleton, define “Resorption”
Removing bone with osteoclasts.
Define
Wolff’s Law
A theory developed by German surgeon, Julis Wolff, which states that bone will adapt to the loads placed upon it.
How do the boned in human skeleton adapt when lifting heavy weights?
The body responds by laying down extra bone to thicken the diameter in a process called deposition.
Define
Osteoclasts
Cells responsible for bone resorption.
Define
Osteoblasts
Cells responsible for bone deposition.
Define
Osteocytes
Mature bone cells that maintain a bone’s matrix.
Define
Periosteum
The outer covering of bone where osteoblasts are located.
Define
Endosteum
Connective tissue that covers the inside of bone and medullary cavity.
Define
Medullary cavity
Central cavity of the bone shaft where marrow is stored.
Bones consists of which two materials?
Compact (cortical) bone: This hard outer layer of dense tissue is strong, solid, and resistant to bending. Approximately 80% of a person’s skeletal mass comes from compact bone.
Spongy (trabecular or cancellous) bone: Light, porous inner bone material that forms a latticework of bony structures called trabeculae. Osteoporosis mainly affects spongy bone.
Define
Osteoporosis
Bone disease characterized by a loss in bone mass and density.
In the context of the human skeleton, define “Bony protrusion”
An eminence on the surface of bones that increase strength and contact area for muscle attachments.
From which sources to the bones receive its blood?
Bone receives its blood from three sources: periosteal vessels, nutrient arteries, and epiphyseal vessels. These three vessels ensure that blood is available to all areas of the bone, from the innermost spongy bone to the outer compact bone.