Module 3 - Support and Movement Flashcards Preview

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Flashcards in Module 3 - Support and Movement Deck (62):
1

Function and roles of muscular system

To convert chemical energy into mechanical work

- movement
- support
- protection
- body temperature regulation
- nutrient storage

2

4 characteristics of muscle tissue

excitability and conductivity
- can response to stimuli
- produce an action potential
- carry a chemical or electrical signal

contractility
- can shortent and thicken

extensibility
- can be stretched without damage
- muscles often work in pairs

elasticity
- strain energy storage

3

What are the 2 types of filaments?

Actin - thin
Myosin - thick

4

What is the M-line?

mid line of myosin

5

What is the Z-line?

ends of sarcomeres

6

What is the H-zone?

myosin no actin including M-line

7

What is the A-band?

range of myosin

8

What is the I-band?

actin including Z line

9

4 types of joints

-Nonaxial
- Monoaxial/uniaxial
- Biaxial
- triaxial/multiaxial

10

Examples of nonaxial joints

gliding
- carpels, vertebrae

11

Examples of monoaxial/uniaxial joints

hinge
- humerous and ulna
pivot
- radius and ulna

12

Examples of biaxial joints

ellipsoid
- wrist
saddle
- metacarpels

13

Examples of triaxiak/multiaxial joints

ball and socket
- shoulder

14

What are the three planes of movement?

Sagittal (median)
Coronal
Transverse

15

What is the sagittal/median plane of movement?

- forward and back
- cause flexion (decrease angle) and extension (increase angle) of joints

16

What is the coronal plane of movement?

- left and right
- causes adduction (body part moves toward midline) and abduction (body part moves away from midline)

17

What is the transverse plane of movement?

- rotation about the long axis (head to toe)

18

Define motor unit

a motor neuron plus all the muscle fibres it innervates

19

What is a muscle fibre?

A bundle of myofibrial (chains of sarcomeres)

20

In what manner do action potentials spread across motor units?

Like ripples in water

21

What is Rigor mortis?

Rigor mortis occurs when ATP stores deplete in a deceased body, causing the myosin heads to remain bound to the actin leading to the stiffening of the body.
- begins immediately
- obvious 2 - 4 hours post mortem
- complete by 6-12 hours post mortem
- lasts 15-25 hours
- disappears with tissue decay

22

What is Rhabdomyolysis?

Rhabdomyolysis is the disintergration or dissolution of muscle, associated with excretion of myoglobin in the urine.

23

What are the symptoms of Rhabdomyolysis?

- dark urine
- weakness
- renal failure
- compartment syndrome

24

What are the causes of Rhabdomyolysis?

- vigorous exercise
- alcoholism
- drugs
- heatstroke
- seizures
- crush injuries

25

What are the treatments of Rhabdomyolysis?

- plenty of fluids
- diuretics (drugs to increase urination)

26

3 basic mechanical roles of skeletons

- support (against gravitation acceleration)
- protection (of internal organs)
- movement (of body)

27

2 metabolic roles of skeletons

- nutrient storage - minerals and lipids, particulary Ca2+ and P3-
- Blood cell formation - a large role of the axial skeleton in adults

28

Types of skeletons

- Hydroskeleton
- Exoskeleton
- Endoskeleton

29

Features of endoskeletons

- internal skeleton consisting of two parts: axial (skull, jaw, spine and ribs - 80 bones in humans (22 from skull)) and appendicular (limbs/anything coming off the axial skeleton - 126 bones in humans)

30

Features of exoskeletons

- calcium carbonate shells or cuticle (chitin - coat secreted by epidermis)
- provides protection from predators and the environment
- muscles attach to the inside of the skeleton
- arthropods either enlarge or shed and replace exoskeleton as they grow

31

Features of hydroskeleton

- fluid held under - pressure in a closed, semi-rigid body compartment
- muscles anchor to compartment wall and change shape of compartment
e.g. earthworms

32

4 types of bone

- Long
- Short
- Flat
- Irregular

33

Examples of irregular bones

- important for support, movement and hematopoiesis
- e.g. vertebrae, os coxae, pneumatic bones

34

Examples of flat bones

- important for protection/hematopoiesis
- e.g. sternum, scapula, ribs

35

Examples of short bones

- square shaped
- important for movement
- e.g. carpals, tarsals, sesamoid bones

36

Examples of long bones

- shaft with end
- important for leverage/movement
- e.g. femur, phalanges

37

Compact vs. trabecular bone

compact - hard outer of bone
trabecular - spongy inside, a 3D lattice

Both are made of same material, just organised differently to have different mechanical properties.

38

Primary vs secondary bone

Secondary bone is the new bone - produced as tubes up through the primary bone

39

What are the two components of bone tissue?

hydroxyapatite and collegen

40

What is hydroxyapatite?

- inorganic: Ca10(PO4)6(OH)2
- about 2/3rds of bone tissue
- stores/contains 99% of the body's calcium (1-2kg- the most abundant mineral in the body)
- bone brittleness

41

What is collegen?

- comprises roughly 1/3rd of bone tissue
- bone flexibility
- reinforcing material, like steel rods in concrete

42

What causes rickets?

A lack of hydroxyapatite makes the bone more flexible causing them to bend under the weight of the body

43

Osteoblasts vs osteoclasts vs osteocytes

Osteoblasts - create bone matrix
Osteoclasts - breakdown bone matrix
Osteocytes - maintain bone matrix

blast - build
clast - opposite of build
cytes - maintain

44

What percentage of bone mass is bone cells? What is the rest?

2% - the rest is matrix, which is hydroxyapatite and collegen

45

How does the number of bones change throughout life? Why does this happen?

11 weeks prior to birth - 800 ossification centres
At birth - 450 ossification centres
Mature adults - 206 bones

Growth plates fuse making bones become one.

46

How does bones grow or be repaired?

The bone wall stays the same thickness but the width increases.

Osteoclasts excavate a tunnel 'parallel' with the diaphysis and osteoblasts subsequently refill the tunnel with osteoid that gradually mineralises. This is the bone modeling unit (BMU). Damage is constantly repaired.

47

What shape of bone resists bending best?

Hollow oval bones is better than round or solid bone.

48

4 types of locomotion in water

- Undulation
-side to side motion
- side movements cancel each other out to push the animal forward
- can be restricted e.g. cuttlefish
- Flapping
- Rowing
- Jet propulsion

49

How is buoyancy controlled in water?

Gas bladders increase and decrease the density of the body and therefore its buoyancy to overcome gravity.

50

Important aspects in locomotion in air, features that make it possible and the 4 types

Friction and gravity are very important.

Birds have light bones (air pockets), no teeth and usually no bladder.

Flapping

Bounding
- for body mass less than 300g
- energetically economical
- muscles used at their optimum power output

Soaring
- energetically economical
- postural muscle use
- large wings required

Hovering
- energetically demanding
- hummingbirds get lift on up and down strokes unlike other birds

51

Important variable and 4 types of locomotion on land

Gravity is the most important variable to overcome, and friction is of lesser concern unless moving fast.

- Crawling
- Walking
- Running
- Jumping

52

5 types of crawling

- two-anchor
- pedal wave
- peristalsis
- serpentine crawling, sidewinding, concertina
- amoeboid crawling

53

3 types of running

- plantigrade - flat foot
- digitigrade - on toes
- unguligrade - on fingertip (elongation of light distal limb)

54

With the same number of bone, is more or less skeletal elements better?

Less skeletal elements result in stronger bones as the bone is less distributed.

55

3 types of locomotion in primates

Braciation
- pedulum swinging through trees
e.g. gibbon, orangutang

Quadrapedalism
- knuckle walking (4 limbs)
e.g. baboon, gorilla, chimpanzee

Bipedalism
- 2 limbs
- humans

56

4 stages of human gait cycle

Heel strike
Stance
Heel off
Swing

2 periods of double limb support and two periods of single limb support

57

Benefits of bipedal gaits

- minimises energy costs by reducing movement of cenre of gravity
- increases stride length
- maintain balance

1000 muscles, 200 bones, 100 moveable joints

58

How fast can we walk, how fast do we walk and why?

Acceleration is needed to move a mass in the arc of a circle = v squared/r

Gravitational acceleration acts on our centre of mass which moves in the arc of a circle with a radius equal to the lower limb length. Therefore, g = v^2/r

v(max) = sqrt(gr) = 3.1m/s

59

How much energy of centre of mass can be conserved in walking?

60-75%

60

How is lower limb length related to maximum walking speed?

Max walking speed is inversely proportional to lower limb length.

61

What are canaliculi?

The osteological features that allow osteocytes to communicate with each other

62

What is haematopoisesis and haemopoesis?

Haematopoisesis - formation of new erythrocytes (RBC's)

Haemopoesis - formation of the hemoglobin protein