Intro to musculoskeletal system Flashcards
What is diaphysis?
Middle section of a long bone
What is epiphysis?
End sections of a long bone
What is metaphysis?
Where the middle and the end of the long bone meet
- contains the growth plate (physis)
What is the medullary cavity?
Contains bone marrow
What is bone remodelling?
The continuous deposition and resorption of bone
- rate is influenced by hormones
- Forces like shear, tension and compression lead to remodeling
Hormones affecting rate of bone remodelling
- PTH
- Calcitonin
3x ways of classifying bones
- topologically; location
- formation/growth; endochondral or intramembranous
- shape; long/short, sesamoids
LONG BONES
- two ends
- growth plates
- compact and spongy bone
- medullary cavity
SHORT BONES
- as long as they are wide
- compact and spongy bone
- no medullary cavity
FLAT BONES
- thin, wide flat
- compact bone that surrounds spongy
SESAMOID BONES
- found in tendons and ligaments
- close to joints
What is apophysis?
protrusion that develops from independent ossification centre
- attachment sites for tendons and ligaments
- called tuberosity
What is a foramen?
- opening in the bone
- passages for nerves, blood vessels or muscles
What is a fossa?
Cave or depression in the bone
- accommodates muscles & other structures
Cranial bones
- composed of mostly paired bones
- ventral part of cranium, bones are endochondral
- dorsal part of cranium, bones are intramembranous
- many foramina for nerves and blood vessels
Mandibular bones
- several foramina
- mandibular foramen; inferior nerves
- coronoid process; attaches temporalis
- angular process; attaches masseter
- masseteric and pterygoid fossae
- body and ramus (vertical)
- two mandibular bones joined at the symphysis
Hyoid bones
- series of bony rods
- suspend the tongue and larynx
- stylohyoid visible in the guttural pouch of horse
Types of vertebrae
- cervical; neck (7 in mammals)
- thoracic; articulate with ribs
- lumbar; lower back
- sacral; fused together and articulate with pelvis
- caudal; tail
Between vertebrae
- intervertebral discs between vertebrae
- spinal nerves exit via intervertebral foramina
Ribs
- paired
- dorsal part is bony ventral is cartilage
- articulate with sternum directly or to cartilage of above ribs
- cartilage of last rib may fail to connect; floating rib
Sternum
- Most cranial element is called manubrium
- Xiphoid cartilage attaches to linea alba
Pelvic limb
- pelvic girdle
- articulated with the sacrum dorsally
- 3x bones (ilium, pubis, ischium)
- fuse into one structure
Leg bones
- Femur; offset femoral head for articulation in the acetabulum
- prominent trochanters for muscle attachments
- Patella; sesamoid bone in quadriceps tendon
Birds skeleton differences
- modified thoracic limb; additional bone called the coracoid
- Fusion of many bones for strength and weight reduction
- Loss of teeth
- Pneumatised bones, air sacs in the medullary cavity
- Medullary cavity; important calcium reservoir to calcify egg shells
Reptile skeleton
- less bone remodelling
- elastic cartilage in skull, movement between bones
- have coracoid
- vertebrae (presacral, sacral and caudal)
- epiphysis don’t close
Types of muscle
- smooth; involuntary
- striated; voluntary
- cardiac
Striated muscle
- contains many fascicles enclosed in epimysium
- fascicles consist of many muscle cells bound in perimysium
- many mitochondria
- many contractile myofilaments in interlocking arrangement
What is the fascia?
- Collective term for the connective tissues
- endomysium
- perimysium
-epimysium
What are Sharpey fibres?
when muscles attach directly to bone collagen fibres continue as sharpey fibres
Tendons
- collagen fibre bundles in a regular arrangement
- primary, secondary and tertiary bundles
- low metabolic needs
Tendon sheaths and bursae
- sacs or tubes containing cavities filled with synovial fluid and with synovial lining
- protect against pressure and friction
Types of ligaments
- white ligaments; rich in collagen fibres
- yellow ligaments; lots of elastic fibres
Pennate Muscles
- fascicles insert at an angle to the central tendon
- more fibres beside each other more force generated
- pennation angle changes as muscle shortens
Types of muscle shapes
- Parallel
- Pennate (uni-, bi-, multi-)
-circular
Parallel muscles
- fibres are parallel with each other and the line of action
- pennation angle is 0 degrees
- more fibres packed in series, more shortening
Types of muscles fibre contraction
- Concentric; muscle shortens
- Eccentric; muscle lengthens
- Isometric; muscle stays same length
Agonist/ antagonist
- antagonistic pairs
- agonist is the prime mover
- antagonist opposes that movement
- Synergist, modifies the action of the agonist
