Bio Flashcards
functions of the skeletal system
- Support & Protection – support structure for the body and protection for many of our vital organs
- Movement – articulations between bones act like levers for muscles to pull on
- Storage – minerals and fats
- Blood cell production (haematopoiesis)
5 different classifications of bones and name one bone in the human body that belongs in each group.
Flat – scapula Long – femur Short – carpal bones Irregular – vertebrae Sesamoid – patella
gross structure of a long bone
Comprised of an outer layer of compact bone and an inner layer of spongy bone.
• Either side of the compact bone layer is a connective tissue membrane; periosteum on the
outside, endosteum on the inside.
• The ends of the long bones are termed epiphyses, while the shaft in between is the diaphysis.
regions of the vertebral column
Cervical – 7, Thoracic – 12, Lumbar – 5, Sacral – 5, Coccygeal – 4
features of a lumbar vertebrae
▪ large oval body (weight bearing) ▪ triangular vertebral foramen ▪ small transverse process ▪ Short, flat spinous process “stumpy” ▪ Vertically aligned zygapophyseal joints
Pectoral girdle
scapula & clavicle
Arm
humerus.
Forearm
radius & unla
Hand
carpalss, metacarpals,
phalanges (proximal, middle, distal)
bones that make up the pelvis
Pelvis = 2x hip bones + sacrum & coccyx. Each hip bone = ilium, ischium and pubis.
Female Pelvis
wider, oval-shaped
Male Pelvis
– narrower, heart shaped.
Thigh
femur
Leg
tibia and fibula.
Foot
– tarsals, metatarsals, phalanges (proximal, middle and distal).
age-related changes in skeletal properties through development.
Children/adolescence – bone formation exceeds resorption
Young adults – bone formation equals resorption
Adults – bone resorption exceeds formation
In older adults - bone mass, mineralisation and healing ability will decrease with age
the 3 ‘structural’ classifications of joints
Fibrous joints
Cartilaginous joints
Synovial joints
Fibrous joints
– connected by fibrous tissue (collagen), do not have a joint cavity and provide little to no movement
Cartilaginous joints
connected by cartilage, do not have a joint cavity and provide very little movement
Synovial joints
articulating bones separated by fluid filled joint cavity, provides lots of movement
factors that influence the stability of synovial joints
Shape of the articulating surface – how well two bones fit together affects stability
Menisci/articular discs – improve the ‘fit’ of bone ends within a joint cavity
Ligaments – hold joint in place and prevent extreme movements, the more ligaments the more stability
Muscle/tendon tension – if tendons that cross a joint are kept under tension by their muscle contracting, then joint is
more stable
3 common joint injuries?
Sprains – stretched or torn ligaments
Dislocations – bones forced out of alignment
Cartilage tears – compression and shear stress
Osteoarthritis
chronic and degenerative, due to ‘wear and tear’. Cartilage destroyed more than is replaced
Rheumatoid
– chronic and inflammatory, is autoimmune. Inflammation of synovial membrane, erosion of cartilage and
scar tissue formation.
4 functions of skeletal muscle.
Produce movement, maintain posture/body position, stabilise joints and generate heat.
Parallel muscles
long muscles fascicles, allows for larger range of motion at joints, but less force production capability
Pennate muscles
– Short angled fascicles, smaller range of motion, but more force production capability
why active force decreases with
increasing length?
Active force decreases with increasing length as the sarcomeres become excessively stretched, there is not enough
overlap of actin and myosin (hence myosin cannot bind to actin).
features (or structures) within a muscle contribute to active force and which contribute to passive force?
Active force – sarcomere length (myofilament overlap)
Passive force – connective tissues (i.e. epimysium, perimysium, endomysium)
the two ways in which motor unit recruitment can be altered to increase muscle force output.
The number of motor units recruited – i.e. how many motor units are discharging
The discharge rate of motor units – the more action potentials discharged in a short period of time the more force
4 differences between Type I (slow oxidative) and Type IIB (fast glycolytic) muscle fibres?
Contraction speed: slow for type I, fast for type IIB
Fatigue rate: slow for type I (fatigue resistant), fast for type IIB (fatiguable)
Force generated: smaller force by type I, larger force by type IIB
Mitochondria: many in type I, few in type IIB
3 main types of muscle contractions
Concentric: muscle shortens
Eccentric: muscle lengthens
Isometric: muscle remains same length
Which contraction type generates highest forces?
Eccentric produces most force (followed by isometric, then concentric)
