Skeleton Flashcards
What are the four functions of bone
Homeostasis: maintains constant levels of calcium
Support: the bodies frame work holds the body together
Movement/ locomotion:
Protection: protects our vital organs
Blood production: in bone marrow red and white blood cells are produced
Storage: minrals/ fats
Identify and describe the four types of bone cell
OSTEOGENIC (Stem cells)
Location: Deep layers of periosteum/bone marrow
Function: Develop into osteoblasts
OSTEOBLASTS (Building)
Location: Growing portions, endosteum, periosteum
Function: Bone building- synthesise and secrete collagen fibres, initiate calcification
OSTEOCLASTS (Crushing)
Location: Bone surface, site of old/injured/unneeded bone
Function: Bone resorption
OSTEOCYTES (Mature)
Location: Entrapped within matrix
Function: Maintain mineral concentration of matrix
What is bone composed of and how does this influence its characteristics
Bone is comprised of a matrix which is comprised of
29% water
25% collagen fibers
50% hydro phosphate
Collegen makes your body Flexible Able to absorb shock Strong And hard as concrete
Hydro phosphate Is made of - crystallised inorganic-salt -calcium-phosphate -calcium carbonate THIS IS AS HARD AS CONNCRETE
What is the difference between the axial and appendicular skeleton
Axil is everything is on the midline of the body and the
appendicular is anything that isn’t in the midline of the body and it consists of the upper and the lower limb of the body
what is the importance of red bone marrow
RED BONE MARROW Location: Cancellous Importance: White blood cell production and maturation Red blood cell production Platelets
what is the function of the macro structures of the long bone (EPIPHYSIS METAPHYSIS EPIPHYSEAL PLATE DIAPHYSIS ARTICULAR CARTILAGE, PERIOSTEUM) ?
EPIPHYSIS Enlarged ends of the bones Connects with ends of other bones- JOINTS Outer layer- COMPACT Inner layer – CANCELLOUS
METAPHYSIS
Connects the epiphysis to the diaphysis
Forms part of the ‘Growth’ plate
EPIPHYSEAL PLATE Growth plate Contains osteoblasts Calcifies when stopped growing Influenced by Human Growth Hormone
DIAPHYSIS
The shaft of the bone
Made from COMPACT bone
Hollow centre- Medullary cavity (filled with YELLOW BONE MARROW)
Lined by ENDOSTEUM
‘NUTRIENT ARTERY’- blood vessels which supply nutrients to bone
Penetrates bone via NUTRIENT FORAMEN
ARTICULAR CARTILAGE Thin layer ‘hyaline’ cartilage Found on epiphysis at joints Protects ends of bone from damage due to joint movement Reduces friction
PERIOSTEUM Tough, white fibrous tissue covering around the bone. Not found at joints Rich supply of blood and nerves Helps supply nutrients Pain receptors
What is the difference between compact and cancellous (spongy) bone
Compact Hard, dense and rigid –Filled with minute holes and passageways •Blood vessels located within holes •Supply with nutrients and oxygen
Cancellous
Thin, bony elements (trabeculae)
–Porous (hence ‘Spongy’)
–Contain bone marrow
•Formation of red blood cells (haemopoesis)
what are the four general types of bone
There are four general bone types classified according to shape:
1) Long - eg. humerus, femur.
2) Short - eg. carpals and tarsals.
3) Flat - eg. cranial bones, sternum
4) Irregular - eg. vertebrae.
Explain the sliding filament theory of muscle contractions
Step one cross bridge formation the Myerson binds to the exposed site and a nerve impulse or release calcium ions which attached to the tropisin this causes the proposition to move exposing the Myerson binding site the mice and head is then activated and ATP is hydrolysed form ATP and energy is released the Myosin head moves to attach to the Myerson binding site and the bridge is formed
Step two the power stroke
The Myerson head pivots and moves acting towards the M-line multiple myosin heads will be performing the power/at any one time moving acting towards the M line this brings the Z lines together hence the muscle contraction occurs
Step three cross bridge detachment- The ATP attaches to the myosin head bond between the Myosin head and the myosin binding site weakens and the myosin head detaches
Step four reactivation of myosin head- ATP Hydrolysis to form ADD and PI Energy released causes the Myerson head to move down the cycle repeats it self as long as the Myosin binding site is exposed The contraction and with calcium ions are actively taken up by Sarcoplasmic plasmic retilium The tripod from returns to the original shape and tryposin moves to cover the myosin binding site  and the Sacramere relaxes and the muscle also relaxes
define the following microscopic parts off bone HAVERSIAN SYSTEMS, LAMELLAE LACUNAE CANALICULA TRABECULAE
HAVERSIAN SYSTEMS
AKA- Osteons
Cylindrical structures which extend length of bone
Arrangement- provides strength to compact bone
Contain CENTRAL CANAL
Blood vessels, nerves, lymph vessels
LAMELLAE
Surround the central canal
Layers of bone matrix
LACUNAE
Spaces between lamellae
Osteocytes are located
CANALICULA
Fine, hair-like structures that interconnect lacunae
Osteocytes cytoplasm extensions enable communication with adjacent cells
Supply of blood- provide nutrients/remove wastes
TRABECULAE Thin, flat bony plates No distinct organisation Porous structure Osteocytes and osteogenic cells located within pores Red bone marrow
Where is cartilage found and what are its general characteristics
cartilage is found between our joints and it is strong firm and flexible cartilage does not have any nerves or blood vessels so for blood too travel to the cartilage it must diffuse
explain the difference between hyaline cartilge elastic cartilage fibrocartilage
elastic: is flexible, firm and elastic found in the ear
fibrocartilage: rough and not compact is the strongest cartilage in the body and is found in has yellow pecdirium intervertebral disks and high impact areas (tendons) has no pectorium
hyaline: the most abundant found at the ends of bone has pecdoerium reduces friction is flexible but weaker than other types of cartilige
Properties of muscle tissue
Contractility is the ability of muscle cells to forcefully shorten. For instance, in order to flex (decrease the angle of a joint) your elbow you need to contract (shorten) the biceps brachii and other elbow flexor muscles in the anterior arm. Notice that in order to extend your elbow, the posterior arm extensor muscles need to contract. Thus, muscles can only pull, never push.
Excitability is the ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone.
Extensibility is the ability of a muscle to be stretched. For instance, let’s reconsider our elbow flexing motion we discussed earlier. In order to be able to flex the elbow, the elbow extensor muscles must extend in order to allow flexion to occur. Lack of extensibility is known as spasticity.
Elasticity is the ability to recoil or bounce back to the muscle’s original length after being stretched.
Functions of muscle tissue
Movement: Our body’s skeleton gives enough rigidity to our body that skeletal muscles can yank and pull on it, resulting in body movements such as walking, chewing, running, lifting, manipulating objects with our hands, and picking our noses.
Maintenance of posture: Without much conscious control, our muscles generate a constant contractile force that allows us to maintain an erect or seated position, or posture.
Respiration: Our muscular system automatically drives movement of air into and out of our body.
Heat generation: Contraction of muscle tissue generates heat, which is essential for maintenance of temperature homeostasis. For instance, if our core body temperature falls, we shiver to generate more heat.
Communication: Muscle tissue allows us to talk, gesture, write, and convey our emotional state by doing such things as smiling or frowning.
Constriction of organs and blood vessels: Nutrients move through our digestive tract, urine is passed out of the body, and secretions are propelled out of glands by contraction of smooth muscle. Constriction or relaxation of blood vessels regulates blood pressure and blood distribution throughout the body.
Pumping blood: Blood moves through the blood vessels because our heart tirelessly receives blood and delivers it to all body tissues and organs.
