ic1 msk anatomy Flashcards
what are the types and func of bones
types of bones:
i) long
ii) short
iii) flat
iv) irregular
v) sesamoid
func of bones:
i) support
ii) movement
iii) protection
iv) blood formation
v) electrolyte balance
vi) acid base balance
vii) storage of energy
how many bones does a human adult have (split into the various sections)
total 206 bones
AXIAL SKELETON (80 bones)
1. skull - 29 bones
2. vertebral column - 26 bones
3. thorax (ribs and sternum) - 25 bones
APPENDICULAR SKELETON (126 bones)
1. pectoral girdle and upper limbs - 64 bones
2. pelvic girdle and lower limbs - 62 bones
what is the composition of the bone
- bone tissue
i) hard connective tissue consisting of osteocytes, osteoblasts, osteoclasts
ii) consists of a mineralised matrix with organic (protein fibers primarily collagen and other materials) and inorganic (hydroxyapatite (specialised crystals, Ca10(PO4)6(OH)2), CaCO3, Mg2+, Na+, K+, F-, SO42-, CO32-, OH-) - periosteum
i) fibrous outer and osteogenic underneath layer
ii) not on articular cartilage - endosteum
i) membrane lining inner surface of bony wall - articular cartilage
i) covers articular ends of bone - blood vessels
- nerve
- bone marrow cavity
i) containing endosteum, red and yellow bone marrow cavity - red bone marrow
i) in flat and irregular bones and end of adult femur and humerus
ii) hematopoietic - yellow bone marrow
i) fat tissue
ii) may redifferentiate into red bone marrow upon stress) - diaphysis (shaft), epiphysis (end), metaphysis (contains growth plate in children)
differentiate between the cells found in the bone tissue
osteocytes: trapped in lacunae within the bone matrix and involved in bone maintenance, remodelling and mechano-sensing
osteoblasts: generation of new bone matrix and osteocytes
osteoclasts: for bone resorption and remodelling, dissolves bone matrix and is related to WBC
what are the types of bone tissues
- compact bone tissue
i) found at outer layer of bones and shafts of long bones
ii) almost no space between layers of bone tissue
iii) osteon is the structural unit of the compact bone
iv) other structures in the compact bone tissue incl: osteocytes, lacunae, canliculi, lamellae (concentric, outer circumferential, inner circumferential, interstitial), central canal (haversian), perforating canal (volkmann)
*see structures - spongy bone tissue
i) found at interior of skull bones, vertebrae, sternum, pelvis and ends of long bones
ii) resembles a sponge bc marrow cavities between trabeculae beams or plates of bone
iii) marrow cavities contain red bone marrow
identify and name the bones from head to toe
i) cranium
ii) maxilla
iii) mandible
iv) clavicle
v) scapula
vi) sternum
vii) humerus
viii) ribs
ix) vertebrae
x) ulna
xi) radius
xii) hip bone
xiii) femur
xiv) patella
xv) tibia
xvi) fibula
xvii) frontal bone, parietal bone, temporal bone, occipital bone
what is the structure of cartillages and what types of cartilages are there
i) mainly made of tough cartilaginous connective tissue
ii) found in articulating ends of bones, thorax, trachea, outer ear, nose, larynx
iii) chondrocytes are cartilage cells, found in lacunae and arise from the perichondrium and secrete cartilage matrix
iv) has an extracellular matrix
- collagen/ elastic fiber
- ground substance: H2O, glycosaminoglycans (chondroitin sulfates, keratan sulfate, hyaluronic acid etc), proteoglycans
v) almost always covered by perichondrium
vi) no blood vessels or nerves except in perichondrium
types:
i) hyaline cartilage (most common, lines joints and caps ends of bones; sometimes referred to as articular cartilage)
ii) fibrocartilage (tough and made of thick fiber, strongest and least flexible, found at knee, verterbrae discs, supporting muscles and tendons and ligaments)
iii) elastic cartilage (most flexible, supports parts of body that needs to bend and move to func like ear and larynx (voice box))
*classified based mainly on fiber contents, organisation and location
what is the structure of skeletal muscle fibers
i) elongated, cylindrical, unbranched and striated
ii) plasma membrane (sarcolemma)
iii) cytoplasm (sarcoplasm) comprising of myofibrils and myofilaments, mitochondria, golgi, ribosomes etc, ER (sarcoplasmic reticulum)
iv) multi-nuclei that are flattened and found near periphery beneath sarcolemma
v) muscle -> muscle fasicles -> muscle fiber (cells) -> myofibrils -> myofilaments
what do muscle tissue contain
muscle tissue is composed of specialised cells called muscle fibers
recall from muscle fiber -> myofibrils
sarcomere is the contractile unit of the skeletal muscle and found on myofibril
PARTS OF SARCOMERE
i) thin myofilaments made up of F-actin and attached to Z line (has proteins troponin, which promotes muscle contraction, and tropomyosin which blocks muscle contraction)
ii) thick myofilaments made up of myosin and attached to the M line
iii) M line is the line that runs down the centre of the sarcomere and through the middle of the thick myofilaments
iv) Z line marks the boundary of a sarcomere
v) A zone consists of both thick and thin myofilaments and is the centre of the sarcomere that spans the H zone (and does not change in area during muscle contraction and relaxation)
vi) H zone is the zone that comprises only of thick myofilaments
vii) I zone is the zone that comprises only of thin myofilaments
*when muscle contracts, H zone and I zone and Z line all become smaller but A zone remains the same
differentiate between origin, insertion, action, agonist, synergist and antagonist
origin: muscle attachment that remains stationary while the muscle contracts
insertion: muscle attachment that moves while the muscle contracts
action: a specific movement (eg. flexion, extension) produced by a muscle contraction
agonist: muscle(s) responsible for producing a particular movement
synergist: muscle(s) assisting agonist in performing the particular movement
antagonist: muscle(s) opposing the action of agonist, to control eg. speed and smoothness of movement
what are the two muscles that are frequently used for IM injections and what to note
i) deltoid
ii) gluteus maximus (note to administer in top right quadrant bc other quadrants too close to sciatic nerve)
what are the functions of skeletal muscles
i) produce movement
ii) provide posture, position and stability
iii) support and protect
iv) guards entrances/ exits (eg. urination, sphincter)
v) maintain body temp (chemical energy converted to heat during muscles contraction and shviering)
differentiate between the site and angle of various parenteral administrations
IM: 90deg into muscle
SQ: 45deg into subcutaneous tissue
IV: 25deg into dermis
intradermal: 10-15deg into epidermis
what is a joint and what types of joints are there and which joint is the most mobile
a joint is a specialised site of contact or reunion between two or more bones
i) fibrous
ii) cartilaginous
iii) synovial (with a synovial cavity)
synovial joint is the most mobile
what are the types of synovial joints
i) ball and socket (shoulder, hip)
ii) hinge joint (elbow, knee)
iii) pivot joint (radioulnar - radius and ulna)
iv) planar joint (intercarpal - back of palm aka mid hand area)
