Bones Flashcards
umm bones. basically. yeah.
The human skeleton is divided into two main parts
The Axial Skeleton
The Appendicular Skeleton
The axial skeleton
The Axial Skeleton is composed mainly of the skull, vertebral column, and the rib cage.
Most of the body’s core muscles originate from the axial skeleton.
These core muscles help stabilize and support the axial skeleton, providing proper posture and alignment.
The Appendicular Skeleton
the bones that support the limbs
Pelvic girdle, shoulder girdle, arms and legs
All bones in the human skeleton have features known as landmarks.
What’s a landmark?
A landmark is a ridge, bump, groove, depression or prominence on the surface of the bone that serves as a guide to the locations of other body structures.
Main Functions of Skeletal System
STRUCTURAL SUPPORT: support for soft tissue, including muscles and internal organs
PROTECTION: protective cage for delicate parts of the body (e.g., the brain protected by the skull; rib cage protects heart and lungs)
GROWTH CENTRE FOR CELLS: Red blood cells and platelets are made in bones
RESERVOIR OF MINERALS: A reservoir that the body can call upon in order to regulate the level of calcium and phosphorus in the body
MOVEMENT: Muscles attach to bones by tendons. Muscles contract and move bones to facilitate movement
How are bones classified? what are the 5 categories?
Bones are normally classified according to their shape - long, short, flat, irregular, and sesamoid bones
The long bone are and does ?
Long bones are hard, dense bones that provide strength, structure, and mobility. Long bones in our body are found majorly in the appendicular skeleton.
What is the difference between an epiphyseal plate and an epiphyseal line?
The epiphyseal plate contains cartilage used for producing bone. The epiphyseal line is formed after the epiphyseal plate has stopped producing bone.
Epiphyseal plate
Epiphyseal plate -
Flat plate of hyaline cartilage seen in young, growing bone * Epiphyseal plates are visible in a growing bone.
Epiphyseal line
Epiphyseal line – Remnant of the epiphyseal plate – Seen in adult bones
Periosteum
Superficial connective tissue that covers the length of the bone
Unites with tendons and ligaments at origin and insertion points
Endosteum
Deep connective tissue lining medullary cavity
Medullary Cavity
Inside diaphysis
Filled with red & yellow marrow (as we age)
Red marrow is where blood cell formation occurs
Yellow marrow is composition of adipose cells and connective tissue
Compact bone
Compact bone is the dense part of the bone, and is responsible for structural integrity.
Cancellous bone
Cancellous bone is comprised of spongy, porous, bone tissue and is responsible for providing structural support and flexibility without the weight of compact bone. It is found in most areas of bone that are not subject to great mechanical stress.
How to strengthen bones?
Compact and cancellous bone will strengthen with exercise, specifically exercise that increases the loads to which the bones are accustomed.
Osteons
Composed of tiny, tightly compacted cylinders of bone
run lengthwise within the bone
Haversian canal
bone is arranged around a central “Haversian canal” that contains blood vessels and nerves
Lamellae
look like the growth rings of a tree. Each individual ring is called a lamella
Perforating Canal
“Perforating Canals” are a series of canals that run at right angles to the Haversian canals. They are are empty spaces that allow blood vessels and nerves to travel across bone, linking up with the vessels and nerves in the central canals.
Lacunae
are situated between the lamellae, and are oblong spaces occupied by a branched cell, termed an osteocyte.
Osteocyte
a cell that lies within the substance of fully formed bone. It occupies the small chamber called a lacunae, which is contained in the calcified matrix of bone. Osteocytes are derived from osteoblasts, or bone-forming cells, and are essentially osteoblasts surrounded by the products they secreted. They monitor and maintain the bone matrix.
Canaliculi
microscopic canals between the lacunae of ossified bone
Cancellous bone
Consists of trabeculae: a lattice of thin threads of bone with large spaces between them
Cancellous bone also contains layers of lamellae, lacunae, osteocytes and canaliculi
Cancellous bone is not arranged about a haversian canal, instead blood vessels and nerves are integrated throughout the lattice like trabeculae
Ossification
the process which produces new bone
Ossification depends on the type of bone that is forming
Intramembranous Ossification (Flat bones)
Endochondral Ossification (Long bones)
Osteoclasts
cells that break down the existing bone (resorption) by releasing acids and enzymes
Osteoblast
Protein-secreting cells that build new tissue (osteoid)
Bone growth
early years of human growth: there is more growth than removal.
After puberty, bone growth gradually decreases until about the age 35.
40+ years, the removal of bone is more prominent which accounts for 5 –10% loss of bone mass per decade, 1-2% bone mass per year in elderly.
Where does growth start
The growth process starts in the brain, specifically in the pituitary gland.
What do growth hormones do?
Growth hormone regulates metabolism and helps maintain steady blood glucose levels in adults.
During childhood, high levels of growth hormone stimulate the liver to produce growth factor-1.
Growth factor -1
Growth factor-1 causes muscle and cartilage cells to multiply, leading to growth.
The epiphyseal plates, located at the ends of long bones, are soft disks made of cartilage.
Growth factor-1 stimulates cartilage cells in the growth plates to divide rapidly.
New cells push older cells towards the center, gradually elongating the bone and making us taller.
Simple fracture
A simple fracture occurs when there is no separation of the bone into parts, but a break or crack is detectable
Compound fracture
A compound fracture occurs when the bone breaks into separate pieces
Comminuted fracture
A compound fracture occurs when the bone breaks into separate pieces
types of simple fractures
simple fractures:
a) greenstick fractures - common in young people due to flexibility of young bone
One side of fracture is broken while other side is bent (like a green tree branch)
Must be bent back into place and casted for 6 weeks
b) hairline fractures (sometimes referred to as a stress fracture)
-tiny crack(s) in the bone
- fatigue induced due to repeated stress over time
result of accumulated trauma from repeated loading such as running or jumping
common overuse injury in athletes
rest is the usual treatment
types of compound fractures
compound fractures:
a) transverse- straight across
b) oblique- angled break
c) spiral- angled and twisted
d) avulsion- small piece of bone torn away by force of a tendon or ligament
Caused by overexertion or sudden traumatic pulling during an accident
types of comminuted fractures
Characterized by the bone being broken in more than 2 places
Bone splits into fragments due to pressure applied to both ends of the bone
Bone fragments are jammed into each other
Open fractures
Break in the skin
Caused by high energy injuries such as car crashes, falls, or sports injuries
Harder to treat due to high risk of infection
Signs & symptoms of a bone fracture
Signs/Symptoms of a bone fracture include:
Swelling or bruising over a bone
Deformity
Discoloration of the skin
Pain that gets worse when pressure is applied
Loss of function of the limb
Fracture repair
A) Alignment
The fractured ends must be brought back close together in reasonable anatomical position and kept from moving so that the healing process has adequate time to repair the injury.
B) Immobilization
External immobilization tools like casts, splints
Internal immobilization tools like pins, wires, screws or plates can be surgically implanted.
C) Time
The time of immobilization depends on age, physical condition, medical history, etc. The average healing time is between 6-8 weeks.
