Musculo-Skeletal System Flashcards
What is the musculoskeletal system?
system of bones, joints, ligaments, muscles and tendons enabling movement, under control of nervous system
What are bones? What do they do?
living tissue, good blood supply, provides framework, protects internal organs
What does the Axial Skeleton consist of?
skull, spine, ribs sternum, vertebral column
What does the Appendicular Skeleton consist of?
shoulder girdle, upper and lower limbs, pelvic girdle
Describe the structure of bones
- covered in dense connect tissue called periosteum
- contains osteoblasts - produces new bone cells for growth and repair
- contains sensory nerves - transmit pain signals
What do bones consist of besides osteoblasts and sensors nerves?
25% water, 30% organic material, 45% inorganic salt, minerals,
What two minerals are in bones and how much?
Calcium and phosphate - approx 1kg
Describe compact bones
dense outer layer, appears sold to naked eye
Describe cancellous bones
inner layer, appears spongy, contain red bone marrow
Name the 2 bone cells
osteoclasts & osteoblasts
What do the 2 bone cells do?
osteoclasts - breaks down bony matrix
osteoblasts - bone forming cells
Name the 4 types of bones
long bones, short bones, flat bones, irregular bones
Describe long bones
long, central shaft contain yellow bone marrow, contains red bone marrow
Describe short bones
often cubed shaped, contain mostly spongy bone
Describe flat bones
thin, flattened, usually curved. They have two thing layer of compact bone sandwiching a later of spongy bone between them
Describe irregular bones
complex irregular bone shape e.g. vertebrae
What does the spine contain and what do they do?
spinal column contain a number of bones called vertebrae, they protect the spinal cord
Functions of the skeleton (6)
- support
- protection
- movement
- mineral stage and release
- fat reserve
- blood cell formation
Name 3 types of joints
- fibrous
- cartilaginous
- synovial
Explain fibrous joints
- connective tissues articulating surfaces of bones, binding them together
- joints become fixed e.g. the skull
Explain cartilaginous joints
- connected by cartilage
- allow slight movement between bones e.g. spinal column
Explain synovial joints
- have synovial membrane
- produces and secretes synovial fluids
- fluid lubricates and nourishes the joints
- allows movement
What is the role of the tendons?
bands of fibrous tissue that attach muscle to the periosteum, the fibrous covering the bone. Tendons enable bones to move when skeletal muscles contract.
How do muscles work?
- by contracting each muscle cell can shorten
- cells work together - thousands of muscle cells in each muscle shortens at the same time
Identify the 3 types of muscles
1 - skeletal
2 - cardiac
3 - smooth muscle
What does skeletal muscle cell do?
enables movement, contract when required, produces movement and enables body to be held upright
What does the cardiac muscle cell do?
muscle of the heart, regulated by conducting system of the heart and hormones
What does the smooth muscle cells do?
involuntary, found in the walls of hollow visceral organ. contractions regulates movement of contents of the structure, e.g. food through the intestine or blood flow
Characteristics of muscle
- excitability - able to receive and respond to stimuli
- contractility - able to shorten and thicken
- extensibility - able to stretch
- elasticity - able to return to original shape after contraction or extension
What does the musculoskeletal system do?
provides an internal framework for the body, protects organs by enclosure, anchors skeletal muscles so that muscle contraction can cause movement
How many bones does the human skeleton contain? Which of these are appendicular and axial bones?
206
appendicular - 126
axial - 80
What are the two strong and supportive tissues that form the skeleton?
cartilage and bone
What is the embryonic skeleton made of? then, as a child?
primarily made of hyaline cartilage, and as a young child this is replaced by bone tissue
What is the composition of bone?
- 25% water
- 25% cells
- 50% mineral salts
What gives their hardness?
calcium salts
What gives bones flexibility and tensile strength?
organic parts, especially the collagen fibres
What are osteoblast bone cells?
bone forming (building) cells
What are osteoclast bone cells?
bone destroying (cleaning) cells
Describe compact bone
dense and looks smooth
Describe spongy bone
composed of small needle-like pieces of bone and lots of open spaces.
Explain the function of ‘support’ of the skeleton
bones support the soft tissue and provide attachment sites for muscles, thereby serving as a structural framework for the body
Explain the function of ‘protection’ of the skeleton
bones are a protective layer to the body’s internal organs
Explain the function of ‘movement’ of the skeleton
bones assist skeletal muscles to produce movement
Explain the function of ‘mineral storage and release’ of the skeleton
bones store and release several minerals, especially calcium and phosphorus to help maintain mineral homeostasis
Explain the function of ‘fat reserve’ of the skeleton
yellow marrow of adult bones serve as a site for fat storage
Explain the function of ‘blood cell formation’ of the skeleton
haematopoiesis - blood cell formation, occurs in the red marrow of certain bones
What is essential for bone homeostasis?
certain minerals and vitamins are essential for bone remodelling and maintenance
What mineral and stored in bone tissue for homeostasis?
calcium phosphorus magnesium boron manganese
What vitamins are stored for homeostasis?
A, C & D
Give example of long bones
All the bones of the limbs expect for wrists and ankles
Give examples of short bones
wrists and ankles
Give examples of flat bones
skull, rib cage, sternum
Give examples of irregular bones
vertebrae of the spinal column and pelvis
What makes up most of the bones length and is composed of compact bone?
the diaphysis
What is the diaphysis covered and protected by?
by a fibrous connective tissue membrane called the periosteum
What secures the periosteum to the underlying bone?
sharpey’s fibres (connective tissue fibres)
What is situated at the end of the long bone? and what does it consist of?
epiphysis consist of a thin layer of compact bone enclosing and area filled with spongy bone
What covers the external surface of the epiphysis?
articular cartilage
Explain to use of epiphyseal plates? What happens at the end of puberty?
They cause the lengthwise growth of a long bone. When puberty ends, hormones stop long bone growth, epiphyseal plates have been completely replaced by bone tissue, leaving the epiphyseal lines to mark their previous location
Describe the articulating cartilage
The articular cartilage is glassy hyaline cartilage, it provides a smooth, slippery surface that decreases friction at joint surfaces
What is the function of the skeletal muscle?
to maintain posture and carry out voluntary movement
What is the length of the largest muscle fibres?
up to 1 foot
Describe muscle fibres?
huge, cigar shaped multinucleate cells
Each muscle fibre is enclosed in a delicate connective tissue sheath called…
endomysium
Several sheathed fibres (endomysium) are then wrapped by a courser fibrous membrane …?… to form a bundle of fibres
perimysium
Name the bundle of fibres. (Those enclosed in endomysium and perimysium)
fasicle
What attaches the muscle to the bone?
epimysia blends together into strong cord-like tendons which attach muscle to bone
What factors may cause muscle strength and size to differ?
exercise, nutrition, gender, genetics
What does it mean to say a muscle is attached ‘directly’ to the bone?
the epimysium of the muscle fuses to the direct periosteum, the fibrous membrane covering the bone
What does it mean to say a muscle is attached ‘indirectly’ to the bone?
the epimysium extends past the muscle as a tendon and attaches to the bone
Explain ‘muscle tone’
This is a state of continuos partial contraction. Even when muscle is relaxed some fibres are contracting. The contraction is not visible, but is necessary to remain firm, healthy and constantly ready for action
Explain skeletal muscle function in connection to the nervous system
muscle cells have the ability to receive and respond to stimulus, they contract when stimulated from the nervous system
Define muscle ‘extensibility’
allows muscle cells to strethc
Define muscle ‘elasticity’
their ability to recoil and resume resting length
What is a by product of muscle activity?
generation of body heat
What is used to power muscle contraction?
ATP - energy
How much of ATP escapes as heat from muscle contracting?
3/4
What percentage does skeletal muscle account for body mass?
40%
Skeletal muscle is the muscle type most responsible for heat production. True or False? Why?
True. because it makes up 40% of the body’s mass
Describe the tendons
tough and durable to cross bony projections and not tear
Describe the ligaments
dense, strong, flexible bands of fibrous tissue that binds bones to other bones and provides stability.
Briefly explain muscle movement in relation to the origin and insertion
All skeletal muscles are attached to a bone or connective tissue in TWO points. One being the ORIGIN that’s attached to the immoveable or less moveable bone. Two being the INSERTION is attached to the moveable bone, so that when the muscle contracts the insertion moves towards to origin
What are the classifications of joints?
synarthroses
amphiarthroses
diarthroses
Define the joint classification: synarthroses
immoveable joints
Define the joint classification: amphiarthroses
slightly moveable joint
Define the joint classification: diarthroses
freely moving joint
A joint is a point of contact between…(3)
- two or mores bones
- between cartilage and bone
- between teeth and bones
What changes occur to the ligaments and muscles in early pregnancy?
relaxation due to actions of relaxin and progesterone
Which joints take the most impact during pregnancy?
pelvic joints
Define posture
the position in which someone holds their body when standing or sitting
Define gait
a persons manner of walking
What does the gravid uterus change?
a woman’s centre of gravity
What is a lordosis of the spine and why does it occur in pregnancy?
effects of progesterone, relaxin and weight of the gravid uterus and contents exaggerate the curve of the lumbar/normal spine creating what’s called a lordosis of the spine
Define lordosis
abnormal forward curvature of the spine in the lumbar region, resulting in a swayback posture
What does increased breast size in pregnancy do to the surrounding ligaments and muscles?
stretching of the round ligament and reduce muscle tone
How do the tissues prepare for labour and accommodating the fetal skull?
progesterone and relaxin softening the cartilage and connective tissue in the pelvis
What percentage of women have falls while pregnant?
27%
What should pregnant women be advised regarding vitamin D and calcium?
- why it’s important
- what foods are high in them
- supplements if deficient
- dose 10 micrograms
What are vitamin D and calcium important for (and in reg)
growth of healthy bones and teeth
