ANAT Flashcards
MSK system
- Organ system for movement = muscular + skeletal system
- Provides:
- Form, support, stability, movement to body
- Supports and binds tissues and organs tgt
skeletal functions
- Main storage for calcium and phosphorous (electrolyte balance)
- Regulate mineral balance in bloodstream
- Fluctuation of minerals is HIGH = storage
- Minerals low = withdrawn from bone
- Hematopoiesis occurs in bones (blood formation)
- Yellow bone marrow – fatty connective tissue, in marrow cavity (ENERGY)
- Red bone marrow – hematopoiesis/ blood cell production
- Erythrocytes, PLT, leukocytes formed –> migrate to circ
- Protection of vital organs
- Provide structural support for body
- support, movement
- acid-base balance
- storage of energy
patho
- injury to bone, muscles etc
- arthritis (gout, RA, OA)
- osteoporosis
osteoblast
bone matrix synthesis and subsequent mineralization – BONE GROWTH
○ cells lining bone surface –> rest stage/ surround by matrix to form osteocytes
○ Derived from mesenchymal stem cells
osteocytes
Are osteoblasts that become incorporated within newly formed osteoid –> calcified bone
- bone maintenance, remodel, mechano-sensing (bone organisation) COMMUNICATE
○ situated deep in bone matrix
○ Maintain contact by canaliculi (extensive network of cell processes) contact with osteoblast & osteoclast
○ transduce message to initiate formation and resorption
osteoclast
RESORPTION of mineralised tissue – allow expansion, remodel
○ Multinucleated, like macrophage (derived from hematopoietic lineage)
○ Attached to bone surface at sites of active bone resorption
types of bones
long (leg)
short (appendages)
flat (sternum, skull)
irregular (vertebrae)
206 bones in human
Axial skeleton (80bones)
* Skull (cranial + skull bones) 29
* Vertebral column 26
* Thorax (ribs + sternum) 25
Appendicular skeleton (126 bones)
* Pectoral girdle - shoulder. UPPER limbs 64
* Pelvic girdle – hips. LOWER limbs 62
bone composition
- Bone tissue (Hard connective tissues, calcified = COMPACT / SPONGY)
- Periosteum (outer most covering)
- Marrow cavity (RED/YELLOW)
- endosteum (lines marrow cavity)
- Articular cartilage (covers bones end)
- Blood vessels
- nerves
part of bone
diaphysis (shaft)
epiphysis (end)
metaphysis (near end) & epiphysis (disc of cartilage –> line) child –> adult
bone tissue cells and matrix
- Cells
○ Osteocytes (Trapped in lacunae within bone matrix)
○ Osteoclasts (Inside to dissolve bone, allow for expansion)
○ Osteoblasts (outside) - Mineralised matrix
○ Organic
○ Inorganic
organic components of bone
○ Organic: protein fibers (collagen), cells, osteoid (by osteoblast = ground substances + collagen fibers)
contribute to structure, flexibility, tensile strength of bone
inorganic components of bone
○ Inorganic : hydroxyapatite (Ca10 (PO4)6 (OH)2), CaCO3, Mg, Na,K, F, SO4, CO3, OH
makes bones hard
compact bone
- found on Outer layer of ALL bones & shaft of long bones
- Almost no space b. layers of bone tissue
○ OSTEON (structural unit)
* Osteocytes, Lacunae, Canaliculi
○ Lamellae (collagen fibers)
* Concentric lamellae, interstitial lamellae
○ Central & perforating canals (in each osteon) - osteon: lamaellae alternating direction + osteocytes in between + lacunae + canaculi (connect the layers)
spongy bone tissue
- Interior of skull, vertebrae, sternum, pelvis, end of long bones
- Marrow cavities between trabeculae beams/ plate of bone
○ Contains RED bone marrow in cavity
○ Osteoblast (Surface), osteocyte, osteoclasts (found in specific parts, may be bigger)
periosteum
outermost
* Fibrous outer & osteogenic underneath layer
- thin layer of membranous connective tissue that covers all bones in the body.
- Not on articular cartilage
marrow cavity
- Holds red/ yellow bone marrow
- Has endosteum lining
RED: in flat, irregular bones. Ends of adult femur, humerus (HAEMATOPOIETIC)
YELLOW: fat tissue (differentiate into RED upon stress)
skull
frontal bone
parietal bone
temporaral bone
occipital bone
maxilla
mandible
impt bones
clavicle, scapula
sternum, rib
humerus, ulna (in), radius (out thumb)
hip bone
femur
patella
tibia, fibula
cartilage
- Made of tough cartilaginous connective tissue
- Eg: found in articulating ends of bones, thorax, nose, trachea, outer ear, larynx
cartilage composition
- Chondrocytes
- Extracellular matrix
- Perichondrium (cover): dense layer of fibrous connective tissue that covers many types of cartilage in the body
- Since cartilage no blood vessels or nerves, supplied by perichondrium
ECM in cartilage
- Collagen/ elastic fibers (cartilage cells in lacunae)
- Arise from perichondrium & secrete cartilage matrix
- Ground substances
- (H2O, proteoglycans, glycosaminoglycans – chondroitin sulfates, keratan sulfates, hyaluronic acid)
3 types of cartilage
based on fiber content, organisation, location
- hyaline
- elastic
- fibrocartilage
hyaline cartilage
Coastal ribs (sternum)
Bronchi, trachea, larynx
Ends of most bones, Articular cartilage of knee
- Translucent
- Chondrocytes trapped in lacuna - maintain cartilage
- Perichondrium - Made of extracellular proteins (ground subs)
elastic cartilage
External ear, epiglottis
More collagen fibers
Less translucent
fibrocartilage
Articular plate of knee
Pubic symphysis
Intervertebral disc
- elastic fibers in matrix
- easily compressible
joints
- Specialised site of contact or reunion between 2 or more bones
3 joint types
based on structure and range of movement
* FIBROUS (immovable)
* CARTILAGINOUS (range of mobility)
* SYNOVIAL (free)
fibrous joint type
- FIBROUS – dense connective tissue
- Very limited mobility
□ no joint cavity
□ for connecting bones that dont require a lot of movement (suture lines of skull after development)
cartilaginous joint types
- CARTILAGINOUS – a type of joint where the bones are entirely joined by cartilage,
- Limited mobility and lack joint cavity
- either hyaline cartilage (epiphyseal plate)
- or fibrocartilage (shock absorber, vertebrae, pelvis)
synovial joint types
- SYNOVIAL – between bones that move against each other. Joint cavity filled with fluid (synovial cavity)
- articular cartilage at the ends of bones & Most mobile
- articular capsule (synovial mem + fibrous layer)
- Joint actively moved by contraction (shortening) of skeletal muscles that STRETCHES arocss
□ Eg: shoulder & knee joints
components of synovial joint
- Joint capsule: link bones
- Synovial membrane: Lines and produce fluid (space), lubricate surface of cartilage
- synovial fluid – hyaluronic acid
* lubricant, reduce friction between cartilage - Articular cartilage: end of bone to absorb shock (protects bone, joint)
– some have menisci (separate articular surface)
– bursae (fluid filled sac to cushion tendon from joint)
– tendon (attach muscle to bone)
4 common mechanism of joints
- Ball-and-socket joint
* most mobile, 3D mvoement
* (shoulder, hip) - Hinge joint
* most stable, 1D movement, less dislocation risk
* (elbow, knee) - Pivot joint
* 1 bone (radius) rotate along long axis of another bone ulnar)
* radioulnar/ forearm, head- neck - Planar joint
* glide between bones, small distance
* intercarpal (finger), jaw, ankle
shoulder girdle
(muscle + joints)
- Humerus (ball) + scapula (socket)
- Joint capsule have ligaments (thickened connective tissue)
* Enforce, strengthen joints for stability - Muscles across shoulder joint
xray: cartilage space b. bones where not contacting each other
knee joint
- Hinge (femur & tibia)
- Gliding (femur & patella)
Major components:
* Bone: femur, tibia, patella
* Articular cartilage (a fibrocartilage)
* No blood supply, synovial mem supplies
* Meniscus: c-shaped cartilage that act as shock absorber (incr fitness + stability)
* joint (snovial mem, joint capsule)
* ligaments
perichondrium vs periosteum
perichondrium (hyaline cartilage)
* dense connective tissue layer, covers cartilage
* fibroblast cells
* protect bone from injury/ elasticity
periosteum
* layer of connective tissue that promotes bone growth and devvelopment
* osteoblast cells
* surface of bone tissues (not joint face)
* supply blood/ protection/ recovery from #
muscle connection
- Skeletal muscles
- Attached to bones and arranged in opposing grps around joints
- Muscles are innervated – nerved conduct electrical current from CNS to cause muscle to contract
connection between bones, muscles, joints etc
- tendon (muscle - bone)
- tough flexible fibrous connective tissue
- joint (bone articulation)
- allow movement
- ligament (ends of bones)
- limit joint dislocation, restrict movement
- bursae (cushion bones, tendons, muscle)
muscular system defintion
- Extent, direction, force, duration of muscle contraction/ shorten mostly VOLUNTARILY controlled
○ 600 skeletal muscles (Specialised cells = muscle fibers)
○ Distributed in head, neck, trunk, limb
○ 40% of body weight
muscle function
- Work with bones & joints for movement
○ Obvious movement: Walk, pinch, respiration
○ Subtle movement: facial expression - Maintain posture, position, stability (steady)
- Support & protect
○ Abdominal wall - protect internal organs
○ Pelvic diaphragm - support pelvic organs from prolapse - Guard entrances/ exits
○ Sphincters – voluntary swallowing, micturition, defecation, parturition - Maintain body temp
○ Convert Chemical –> Heat during muscle contraction and shivering - Moves human body, organs , pump blood
types of muscle tissue
- skeletal
- cardiac
- smooth
cardiac
- Striated & involuntary
- Fibers uninucleated
- Only cover walls of heart
smooth muscle
- Non-striated & involuntary
- Fibers, spindle shaped, uninucleated
- Cover wall of internal organs
skeletal muscle
- Striated & voluntary, cylindrical, unbranched
- plasma mem (sarcolemma), cytoplasma (sarcoplasm)
□ Myofibrils & myofilaments
□ Mito, GA, ribosomes, ER - Multi-nucleated
- Flattened, near periphery beneath sarcolemna
- Attached to skeleton (mostly)
skeletal muscle is made of
Myofilaments –> myofibrils –> muscle fibers (cells) –> muscle fascicles –> muscle
- Sarcomere: contractile unit of skeletal muscle
Z line, M line
- Z line: thin myofilaments (made of F-actin) attached to
- M line: thick myofilaments (made of myosin) attached to
I, A, H band
- I band: disc, zone with only thin myofilaments
- A band: zone of thick myofilaments
- H zone: zone with only thick myofilaments (not overlap with thin)
relax
- I band: widen
- A band: shorten
- H zone: incr
3 parts of muscle for a movement
- Origin – muscle attachment that remains STATIONARY while musc contracts
- Insertion – muscle attachment that MOVES while musc contracts
- Action – specific movement produced by musc contraction
* Flex, extension
