The Musculoskeletal System Flashcards Preview

Health and Human Biology NURS1001 > The Musculoskeletal System > Flashcards

Flashcards in The Musculoskeletal System Deck (21)
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1
Q

what is the axial and appendicular systems.

A

axial: sternum, skull, ribs, spine (vertebrae)
appendicular: bones of the appendages (arms and legs) and the girdles (shoulder and pelvic) that connects them with the axial skeleton
- pelvis, femur, tibia, ulna, humerus

2
Q

what is the vertebral column?

A

intervetebral discs separate the vertebrae form one another.
top and bottom of each disc has a layer of hyaline cartilage. they are used to absorb shock and create spaces between vertebrae

3
Q

what is the atlas and the axis?

A

atlas: first cervical vertebra, supports the skull
axis: second cervical vertebra, enables pivot movement of the head

4
Q

what is the thoracic vertebrae?

A

supports ribs and have special structures for rib head and tubercle attachment

5
Q

what is the lumbar vertebrae?

A

the largest and strongest in the vertebral column. they support the body’s weight.

6
Q

what are the benefits of compact and spongy bone?

A

compact bone is good at providing protection and support.

spongy bone is lightweight and provides tissue support

7
Q

what are joints?

A

a part of the body where two or more bones meet to allow movement
- joints may be supported by fibrous structures (ligaments) connecting one bone to another

8
Q

what are tendons?

A

fibrous connective tissue that connects muscle to bone

9
Q

what are synovial joints?

A

most common type of joint, allows for ‘free movement’

10
Q

what type of cells do bones consist of?

A

osteoprogenitor cells (bone stem cells able to differentiate into other types of cells)
osteoblasts (bone-building cells that secrete matrix)
osteocytes (mature bone cells)
osteoclasts (remodel bones and cause them to release calcium)

11
Q

what movements do synovial joints allow?

A
  • gliding (e.g. at the wrist)
  • angular movements (flexion, extension, abduction, adduction, circumduction)
  • rotation (head, neck and lower limb)
12
Q

what would happen if there was no synovial fluid?

A

synovial fluid is a slippery fluid that occupies all free spaces within the joint capsule
- it reduces friction, without it the joint surfaces would rub away as a result of friction

13
Q

what happens to joints as humans age?

A
  • decreased production of synovial fluid
  • thinning of articular cartilage
  • loss of ligament length and flexibility
14
Q

describe homeostasis in bones, ageing and bone tissue

A

although bones stop growing in length by adulthood, bone continually renews itself throughout life.
Spongy bone is replaced every 3-4 years and compact bone roughy every 10 years.

15
Q

how does movement occur?

A

movement is produced by muscle contraction pulling, via a tendon, on one muscle while relaxation of the opposing muscle occurs
- coordination of motor activity is essential for any purposeful movement to occur

16
Q

what are muscle cells, and what do they contain?

A

muscle cells are cylindrical and called muscle fibres. each muscle fibre contains muscle filaments or myofilaments
- these can be thick or thin and aid in muscle contraction

17
Q

briefly explain the sliding filament mechanism.

A

myosin pulls on action, causing the thin filament to slide inward

  • consequently, Z discs move toward each other and the sarcomere shortens
  • thanks to structural proteins, there is a transmission of a force throughout the entire muscle, resulting in whole muscle contraction
18
Q

what are troponin and tropomyosin? what role do they play in muscle contraction?

A

the sliding of the muscle filaments is triggered by an intracellular rise in calcium ion levels.
troponin binding of calcium moves tropomyosin away from myosin-binding sites on actin - allowing cross bridge binding
- this concept connects the events of a muscle action potential with the sliding filament mechanism

19
Q

what would happen in a patient with low calcium levels?

A

hypocalcaemia - muscle cramps, spasms, tremors or tetany from prolonged contraction. muscular and nervous system hyper excited

20
Q

state characteristics and role of smooth muscle in muscle contractions.

A

smooth muscles contractions start more slowly and last longer than skeletal and cardiac muscle contractions.

  • can shorten and stretch to a greater extent
  • provides elasticity, contractility and support
  • found in the walls of blood vessels, around hollow organs, and in layers around the digestive, respiratory, circulatory and reproductive tracts
21
Q

what is the neuromuscular junction?

A

the events at the neuromuscular junction produce a muscle action potential.

  • voltage-gated calcium channels open resulting in an influx of calcium. This causes exocytosis of neurotransmitter (NT) into the synaptic cleft. NT binds to ligand-gated Na+ channels on the motor endplate which cause an influx of Na+ into the muscle. This depolarises it and results in Ca+ release from the sarcoplasm reticulum.