Anatomy - skeletal system Flashcards
What are the three components of the skeletal system
Bone, Cartilage and ligaments
Bone matrix
hardened matrix (mineralised or calcified) by calcium phosphate and other minerals.
Cartilage
forerunner of most bones especially during child to adult development, it covers many bones at joint surfaces
LIgaments
they hold different bones together
How can bones be considered
individual organs consisting of many tissues like Osseous tissue, blood, bones marrow, cartilage, adipose, nervous tissue, fibrous, tissue.
What are the five functions of the skeleton
Support (hold up body, muscles and other structures) Protection ( enclose and protaect brain spinal cord, marrow, heart, viscera) Electrolyte balance ( stores and releases calcium and phosphate ions when required) Acid-base balance ( buffers blood agains excessive pH changes by releasing alkaline salts) blood formation ( red bones marrow makes blood, haemopoietic)
What are the four types of bone
long bone (Femur, Ulna) short bone (Capitate, Talus) flat bone (Scapula, Sternum) irregular bone (Sphenoid bone, vertebra)
Features of long bones
hard shell of compact bone (periosteum and endosteum)
Medulary / marrow cavity - bone marrow in center and spongy bone at ends
Long bones are divided into …
Epiphysis
Diaphysis
and they have an Epiphyseal line
(metaphysis)
Features of Short bones
Diploe
Periosteum - on both sides
Endosteum - lining the diploe
What is on osteon
cylindrical units of the COMPACT BONE with a central canal for nerves and vessels, and then concentric lamella ( layers) containing osteocytes in lacunae which are connected via canaliculi.
What are the four types of bone cells
Osteogenic
Osteoblasts
Osteocytes
Osteoclasts
Osteogenic cells
Stem cells found in the endosteum, inner periosteum and central canals that give rise to osteoblasts.
Osteoblasts
Cells that form bone, they are found in the inner periosteum and in the endosteum, they are non-mitotic, they synthesise the organic bone matrix and they increase in number in response to damage or mechanical stress.
Osteocytes
They are trapped in the matrix and have finger like cytoplasmatic projections for communication and sensing of mechanical stress.
Osteoclasts
They originate from bone marrow stem cells
They reabsorb done
Composition of the Bone Matrix
1/3 Organic - mainly collage and provides flexibility
2/3 Inorganic - 85% hydroxyapatite (Calcium phosphate), 10% calcium carbonate and other salts provides strength
Spongy Bone
It is made of Spicules and trabeculae, contains bone marrow and it is low weight and high strenght
Bone Marrow
Red is haemopoietic
Yellow isn’t but is rich in adipocytes and stores triglycerides.
How is Calcium regulated
Calcium is regulated by:
Cacitriol - causes increase in blood calcium levels
Calcitonin - reduced osteoclast activity and increases osteoblast activity -> causes BLOOD FORMATION (calcium levels drop bc used to make bone)
Parathyroid Hormone - causes increase in osteoclast activity and reduced osteoblast activity -> promotes BONE RESORPTION (so increases blood calcium levels)
What is the concentration level of calcium in blood
9.2 - 10.4 mg/dl
Hypocalcaemia
low blood concentration
Hypercalcaemia
high blood concentration
What is a joint/articulation
it is any two points were two bones meet
What are the four types of bone joints
Bony - synostosis
Fibrous - synarthrosis
Cartilaginous - amphiarthrosis
Synovial - diarthrosis
synonym for bony joint
synostosis
synonym for fibrous joint
synarthrosis
synonym for cartilaginous joint
amphiarthrosis
synonym for Synovial joint
Diarthrosis
synonym for synostosis joint
bony
Synonym for synarthrosis joint
fibrous
Synonym for amphiarthrosis joint
cartilaginous
Synonym for Diarthrosis joint
Synovial
Which are the Bony joints
the ones formed when the gap between two bones ossifies and they become a single bone
e.g. frontal, mandibular and the epiphyses and diaphyses.
What is the movement range of Bony joints
immovable
Which are the Fibrous joints
The ones where bones are joined by the collagen fibres that emerge from one bone and penetrate into the other
What are the three types of Fibrous joints
Suture
Gomphoses
Syndesmoses
What is the range of movement of the fibrous joints
Medium to no movement
Which are the Cartilaginous joints
The ones where bones are joined by cartilage
What are the two types of Cartilaginous joints
Synchondroses (hyaline cartilage)
Symphyses (fibrocartilage) - stronger
What is the movement range of Cartilaginous joints
little to medium movement
Which are the Synovial joints
The ones where two facing surfaces are covered with articular cartilage (hyaline), and there is a joint cavity containing synovial fluid
What are the six types of Synovial joints
Ball-to-socket Condylar/ellipsoidal Saddle Plane/gliding Hinge Pivot
What is the movement range of Synovial joints
large
What are the two first Cervical Vertebrae called
Atlas (C1)
Axis (C2)
How many Cervical vertebrae are there
7
Howe many Thoracic vertebrae are there
12
Howe many Lumbar vertebrae are there
5
How many Sacral vertebrae are there
5
What’s at the end of the vertebral column
The coccyx
