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.
Define
Osteons (Haversian systems)
Functional units of compact bone. These vertically stacked units each contain a nerve and one or two blood vessels.
Define
Trabeculae
Functional units of spongy bone. These consist of a network of plates and rods. Because spongy bone is less dense than compact bone, it contains a richer source of blood vessels.
Can bones senes pain?
YES!
One primary source of bone pain is from the periosteum, the outer covering of bone that contains pain-sensitive nerve endings.
Define
Osteoarthritis
Bone-on-bone contact that results in joint pain and stiffness due to a loss of articular cartilage.
Define
Nociceptors
Pain sensitive nerve endings. The periosteum and endosteum coverings of bone contain nocireptors.
Define
Hyaline cartilage
This deformable but elastic type of cartilage is the most widespread form in the body. It’s located in the nose, trachea, larynx, bronchi; at the end ribs, and at the end of bones of many freely moving joints in the form of articular cartilage.
Define
Fibrocartilage
This tough tissue is located in the intervertebral discs and at the insertions of tendons and ligaments.
Define
Elastic cartilage
As the name implies, this is the most pliable form of cartilage. It gives shape to the external ear, the auditory tube of the middle ear and the epiglottis.
Ligaments consists of which type of collagen?
Type I collagen fibers
Define
Elastin
An elastic protein found in connective tissue that gives the tissue extensibility.
Ligaments are able to regain its original shape after they are stretched, why?
Ligaments also possess a little bit of elastin, an important elastic protein found in all connective tissue that allows those tissues to regain its original shape.
Name and define the three different locations of ligament, in relation to the joint.
Extrinsic ligament: This type of ligament is located on the outside of the joint. An example is the lateral collateral ligament (LCL) on the lateral side of the knee to resist varus stress.
Intrinsic ligament: This ligament is located inside the joint. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are situated inside the knee joint to resist anterior and posterior movement of the tibia, respectively. Capsular ligament: This type of ligament is continuous with the joint capsule. The medial collateral ligament (MCL) is a capsular ligament that resists valgus stress at the knee by keeping the joint approximated.
Define
Extrinsic ligament
This type of ligament is located on the outside of the joint.
Ex: The lateral collateral ligament (LCL) on the lateral side of the knee to resist varus stress.
Define
Intrinsic ligament
This ligament is located inside the joint.
Ex: The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are situated inside the knee joint to resist anterior and posterior movement of the tibia, respectively.
Define
Capsular ligament
This type of ligament is continuous with the joint capsule.
Ex: The medial collateral ligament (MCL) is a capsular ligament that resists valgus stress at the knee by keeping the joint approximated.
Define
Varus
An abnormal joint movement away from the midline of the body. At the knee joint, varus can result in “bow-leggedness.”
Define
Valgus
An abnormal joint movement toward the midline of the body. At the knee joint, valgus can result in “knock knees.”
Define
Joint capsule
A thin, strong layer of connective tissue that contains synovial fluid in freely moving joints.
In the context of connective tissue, define “Creep”
A temporary deformation of connective tissue.
In the context of connective tissue, define “Laxity”
A permanent deformation of connective tissue caused by excessive stretching.
When a ligament has laxity, the joint becomes less stable (i.e., loose) and makes a person more susceptible to joint dislocations and osteoarthritis.
In the context of connective tissue, define “Tear”
A partial or complete separation of a tissue due to a stretch beyond its structural capacity.
A tear occurs when a tissue is stretched beyond its structural capacity. The tear can be either partial or complete. A partial ligament tear can heal with rest, whereas a complete tear usually requires surgery to repair.
Why is it hard fot ligaments to heal, and how long can it take?
Ligaments have a limited capacity to heal due to their low blood supply. Indeed, blood flow to ligaments is less than that of muscle or bone, which is why it can take months or a year to completely heal.
Which type of collaged do the joint capusle consist of?
Type I collagen fibers
Define
Synovial membrane
A thin layer of connective tissue beneath the joint capsule that makes a lubricating fluid.
What is the number one risk factor for injury to any joint?
A previous injury to that joint. This fact is especially true for the ligaments as they have a limited capacity to recover.
When ligament heals from a partial or complete tear, do it become stronger or weaker? And why?
The tissues aren’t as strong as they originally were due to an accumulation of scar tissue. Because scar tissue consists of abnormal collagen, poor cross-linking, and smaller fibrils, it’s a weaker form of connective tissue. This means the ligament is more susceptible to future tears. Therefore, extra care should be taken when stretching or training a joint that endured a ligament injury.
What is the consequence of a joint laxity due to an overly stretched ligament?
And joint laxity caused by an overly stretched ligament can make a joint less stable than it needs to be. Unfortunately, a loose ligament cannot regain its original shape and become “tight” again. Therefore, muscles that surround a loose joint should be sufficiently strong as they must also provide the stabilizing effect the loose ligament can no longer perform.
How many joints are there in the human skeletal system?
360
Define the area of articulation of the sternoclavicular (SC) joint.
Sternum and clavicle
Define the area of articulation of the glenohumeral (GH) joint.
Glenoid fossa (scapula) and humerus
Define the area of articulation of the acromioclavicular (AC) joint.
Acromion process (scapula) and clavicle
Define the area of articulation of the scapulothoracic region (pseudo joint) joint.
Scapula and ribcage
Define the area of articulation of the humeroradial joint.
Humerus and radius
Define the area of articulation of the humeroulnar joint.
Humerus and ulna
Define the area of articulation of the radioulnar (proximal) joint.
Rcadius and ulna (elbow region)
Define the area of articulation of the radius and ulna (elbow region) joint.
Radius and ulna (wrist region)
Define the area of articulation of the radiocarpal joint.
Radius and carpal bones
Define the area of articulation of the sacroiliac (SI) joint.
Sacrum and ilium
Define the area of articulation of the hip joint.
Femur and pelvis
Define the area of articulation of the patellofemoral joint.
Patella and femur
Define the area of articulation of the tibiofemoral joint.
Tibia and femur
Define the area of articulation of the tibiofibular joint.
Tibia and fibula
Define the area of articulation of the talocrural joint.
Talus and tibia
Define the area of articulation of the subtalar joint.
Talus and calcaneus
What does it mean to be double-jointed?
Ligaments are normally very taut around a joint. However, some people are born with “loose ligaments” that allow the joints to move through a greater range of motion than is normal. Even though it might seem cool to have excessive flexibility and appear “double-jointed,” loose ligaments make people more susceptible to joint dislocations and osteoarthritis.
