Musculoskeletal system Flashcards
cartilages
is a semi-rigid connective tissue that is found all throughout the body. While cartilage is not as strong as bone, it is much more resilient and flexible.
Chondroblasts,
which are the mature cells that produce the matrix of cartilage.
Chondrocytes
which are the cells encased within the matrix. These cells live in small spaces within the matrix, called lacunae.
skeletal system
consists of the bones, articulations (joints), cartilage, as well as other connective tissues that help to strengthen and stabilize the bones and articulations.
Cartilage has 3 main functions in the body:
- provides support to the soft tissue
- Provides a protective covering at articulating surfaces.
- Serve as a model for bone growth
There are 3 types [text annotation indicator] of cartilage found in the body:
- hyaline cartilage
- fibro-cartilage
- Elastic Cartilage
Hyaline Cartilage
most common and weakest form in the body
Provides support through resiliency & flexibility
Functions to help support soft tissue, form the fetal skeleton, and serves as a model for most future bone growth
Location: articulations (joints), nose, trachea, larynx, costal cartilage (where the ribs attach to the sternum)
Fibrocartilage
Extremely durable
Functions to act as a shock absorber & help the body resist compressive forces
Location: intervertebral discs, pubic symphysis, menisci
Elastic Cartilage
Contains numerous elastic fibers within its matrix, ensuring resiliency & flexibility
Location: epiglottis (structure in the throat), external ear
Function of the Bone
Support & Protection - Bones serve as a framework of support for the entire body.
Movement - Bones serve as the attachment site for muscles, soft tissue, and some organs.
Hemopoiesis - The process of producing new blood cells is called hemopoiesis
Storage - Approximately 90% of the calcium and phosphate in the body is stored and released by the bones.
long bone
Bones that have a greater length than width
Have a long, cylindrical shaft
Most common
Predominantly found in the upper & lower limbs (femur, humerus, tibia, ulna,
short bone
Bones that have nearly equal length and width.
External surface covers = compact bone; internal = spony bone
Found in the wrist (carpals) and foot (tarsals)
flat bone
Bones that have a flat, think surface.
Provide lots of surface area for muscle & soft tissue attachment
Found in many bones that form the roof of the skull, scapula (shoulder blades), and ribs
irregular bone
Bones with elaborate, complex shapes that don’t fit any of the other classes.
Examples include the vertebra, os coxae (hip bones), and some bones in the skull
Sesamoid Bones
Bones that embedded within a tendon
Found in the knee (patella) and on the bottom side of the foot
diaphysis
of a long bone is its long, cylindrical shaft. The diaphysis plays an important role in help provide leverage and structural support.
The diaphysis of the bone contains the following structures
Medullary Cavity
Endosteum
Periosteum
Epiphysis
of a long bone are its expanded, knobby regions located on the ends of the bone. The epiphysis helps to strengthen to joint by increasing the surface area for bone-to-bone contact and functions as an attachment site for many tendons and ligaments.
Metaphysis
of a long bone is the region of the bone that lies between the diaphysis and epiphysis. In a growing bone, this is the region of the bone that contains the epiphyseal plates, or growth plates.
Osteoprogenitors
Stem cells found within the endosteum and periosteum. These cells help produce more stem cells that later mature to become osteoblasts.
Osteoblasts
: Cells that produce new bone.
Osteocytes
Mature bone cells that reside within the lacunae (small spaces within the matrix). These cells help maintain the bone matrix by detecting any sort of mechanical stress on a bone.
Osteoclasts
These are large, multinucleate, phagocytic cells are involved with a process known as bone resorption (dissolves bone).
a long bone contains 4 major sets of blood vessels:
Nutrient blood vessels The nutrient artery and vein are responsible for supplying the diaphysis of the bone.
Metaphyseal blood vessels The metaphyseal arteries and veins are responsible for supplying blood between the diaphysis and epiphysis.
Eiphyseal blood vessels: The epiphyseal arteries and veins are responsible for supplying blood to the epiphysis and epiphyseal plate.
Periosteal blood vessels The periosteal arteries and veins are responsible for supplying blood to the periosteum of the bone.
During aging, our bones change in two ways:
- We lose the ability to produce organic matrix due to a reduction in the osteoctye activity. This, in turn, results in a failure of the osteoblasts to produce enough new bone growth to maintain the matrix. (a.k.a osteocytes stop telling osteoblasts to build bone)
- We lose calcium and other bone salts.
osteoporosis
The changes in bone that occur during aging can result in a decrease in an individual’s bone density
how many bones does the adult body have
206
axial skeleton
forms the main framework that supports and protects the organs. A total of 80 bones form the axial skeleton, including the skull, vertebral column, and thoracic cage.
appendicular skeleton
is made up of 126 bones (63 per side) and includes the bones of the upper and lower limbs, along with the girdles that help attach the upper and lower limbs to the axial skeleton.
articulation
or joint, is the location of contact between: 1) bones, 2) bones and cartilage, or 3) bones and teeth. Articulations can vary in both stability and mobility, depending on the structure of the joint.
Synarthroses
Immobile joint
Most stable
Example: sutures of the skull
Amphiarthroses
Slightly mobile join
Examples: intervertebral, tibiofibular
Diarthroses
Freely mobile joint
Examples: knee, elbow, shoulder, hip, many more…
Fibrous joints
use dense regular connective tissue to hold bones together. Most fibrous joints are immobile or only slightly mobile.
3 type of Fibrous Joints
Gomphoses
Suture
syndesmoses
Gomphoses
are only found where the roots of the teeth articulate with the sockets in the maxilla and mandible.
Think “peg in a socket”
The teeth are held together by a fibrous peridontal membrane
Sutures
are immobile fibrous joints found between some bones of the skull
Contain distinct, interlocking, usually irregular edges that help increase strength and decrease fractures
Permit the skull to grow as the brain increases in size during childhood
Sutures completely fuse together in adulthood
Syndesmoses
are fibrous joints found between parallel long bones (radius & ulna, tibia & fibula).
Allow for slight movement (amphiarthroses)
Shafts of the parallel bones are bound side-by-side by a broad, ligamentous sheet called an interosseous membrane, which provides a pivot point where the bones can move against one another.
Medullary Cavity
The hollow, cylindrical space within the diaphysis.
Endosteum
A thin layer of cells that lines the inner surface of the medullary cavity. It covers most internal surfaces of the bone and contains osteoblasts and osteoclasts
Periosteum
Long bones are surrounded in a tough, sleeve-like layer of dense, fibrous connective tissue. Periosteum covers all external surfaces of the bone, except the areas that are covered by articular cartilage