Limbs and Back: Week Three Flashcards
1
Q
What type of joint is the elbow joint?
A
Synovial hinge
2
Q
Name the three joints that make up the elbow
A
- Radiohumeral joint: head of the radius and the capitulum of the humerus
- Ulnohumeral joint: trochlear notch of ulna and the trochlea of humerus
- Proximal radioulnar: synovial pivot joint between the circumference of the head of the radius and the ring formed by the radial notch of the ulna and the annular ligament.
3
Q
What are the two collateral ligaments of the elbow?
A
- Radial collateral ligament: lateral epicondyle to blend with annular ligament
- Ulnar collateral: medial epicondyle to coronoid process
4
Q
What ligaments encircles the head of the radius?
A
Radial annular ligaments
5
Q
When does the axillary artery become the brachial artery?
A
Lower end of teres major
6
Q
What branch of the brachial artery runs in the radial grove?
A
Profunda artery
7
Q
Is the brachial artery posterior or superior to the median nerve?
A
Posterior
8
Q
When does the brachia artery spilt into the ulna and radial arteries?
A
Cubital fossa
9
Q
What is the lateral, medial and superior border of the cubital fossa?
A
- Lateral: brachioradialis
- Medial: pronator teres
- Superior: line between epicondyles
10
Q
What are the main contents of the cubital fossa?
A
(Really need beer to be at my nicest)
- Radial nerve
- Biceps tendon
- Brachial artery
- Median nerve
11
Q
The radial nerve gives of a deep branch and a superficial branch. Which one is sensory and which one is motor?
A
The deep is motor (gives of PIP) and superficial is sensory.
12
Q
The flexors of the forearm are mainly innervate by the median nerve. Which two Muslces are the exception?
A
- Flexor carpi ulnaris (ulnar nerve)
- Lateral part of flexor digitorum profundus (ulnar nerve)
13
Q
What is the common origin of the forearm flexors?
A
Medial epicondyle
14
Q
There is the rule of the three for the forearm extensors. What are the three wrist extensors?
A
- Extensor carpi radialis brevis
- Extensor carpi radialis longus
- Extensor carpi ulnaris
15
Q
What are all the forearm extensors innervated by?
A
Radial nerve
16
Q
There is the rule of the three for the forearm extensors. What are the three finer extensors?
A
- Extensor digitorum
- Extensor Indices
- Extensor digiti minimi
17
Q
There is the rule of the three for the forearm extensors. What are the three thumb extensors?
A
- Extensor pollicis longus
- Extensor pollicis brevis
- Abductor pollicis longus
18
Q
What is the function of the brachioradialis?
A
Flexes forearm.
19
Q
Where do the triceps attach?
A
Olecranon of the ulna
20
Q
What type of joint is the proximal radioulnar joint?
A
Pivot
21
Q
In comparison to the bicipital aponeurosis, where about is the medial cubital vein, brachial artery and median nerve?
A
The median vein is superficial and the brachial artery and median nerve are deep.
22
Q
What is the process whereby the cells migrate to the primitive streak?
A
Invagination
23
Q
Name the layers of the mesoderm, central to lateral.
A
Primitive streak - notochord - paraxial mesoderm - intermediate mesoderm - lateral plate mesoderm- extraembryonic mesoderm
24
Q
What two membrane do not have mesoderm?
A
oropharyngeal and Cloacal membranes
25
What at does mesoderm differentiation occur at?
Day 17-21
26
What way do the cells move to form the paraxial mesoderm?
Bilaterally and cranially
27
What does the intermediate mesoderm form?
Genitourinary system
28
What are the two layers of the lateral plate mesoderm?
- Somatic (parietal)
| - Splanchnic (visceral)
29
What layer of the lateral plate mesoderm is connected with the amniotic cavity and which with the yolk sac?
- Somatic: amniotic cavity
| - Splanchnic: yolk sac
30
Which Muslces are formed by the ectoderm?
Smooth muslce of pupil, mammary and sweat glands
31
When do somites appear?
Day 20
32
What is the rate of somite formation until week 5?
They form 3 pairs a day in a craiocaudal sequence
33
What is the process of somite formation called?
Somitogenesis
34
What is the cell transition of cells in the somites?
Mesenchymal to epithelial
35
What three genes are involved in the clock and wave mechanism?
- Wnt
- FGF8
- Notch
36
Describe the clock and wave mechanism
The system tell cell to switch from a permissive to non-permissive state.
There is a wave of FGF8 going up and if it meets a cell activated by a notch (clock gene), it makes it become a somite. Wnt is helping.
37
How many pair are present after around 5 weeks?
42-44
38
What is a somite?
A block of paraxial mesoderm which gives rise to skeletal muscle
39
What do cells in the ventral medial layer form?
Sclerotome
40
What do cells in the dorsal layer form?
Dermoyotome
41
Name the two layers that the dermoyotome splits into
Dermatome and myotome
42
What is the function of MYOD and MYF5?
These are transcription factors that activate muscle-specific genes. They allow differentiation of dermomyotome into myoblasts. They allow non-muscle genes to become muscle cells.
43
Explain the formation of primary myotubes
Myoblasts will secrete ecm and bind via integrin. The cells align and the fuse.
Myogenin mediates this.
44
What gene can reprogramme fibroblasts and adipocytes to become muslce cells?
MYoD1mRNA
45
How is MYOD activated?
Wnt (activating) and BMP (inhibiting) combine. They are from lateral plate mesoderm
46
What tow genes induce Sclerotome formation and where are they from?
Sonic hedgehog and noggin. From the notochord.
47
What does the Sclerotome form?
Ribs and vertebrae
48
Where do the primaxial an abaxial muscle originate?
Myotome
49
What is the function of endomysium, perimysium and epimysium?
- Endomysium covers muscle fibre
- Perimysium covers groups fibres into fascicle
- Epimysium covers muslce
50
What is the meaning of Isotropic (I-band)?
Uniform
51
What protien does the H-zone only contain?
Myosin
52
What does anisotropic mean (A-band)?
Directionally dependant
53
Name the two regulator proteins
Tropomyosin and Troponin.
54
What two proteins connect actin to the z-line?
Nebulin and dystrophin
55
What is the function of titin?
connection of myosin and z-line
56
What protein makes up the m-line?
Myomesin
57
What is the function of alpha-actin?
Make up Z-line
58
How is the remaining acetylcholine broken down?
Acetylcholinesterase
59
What is rigor mortis?
Muscle goes stiff due to no ATP
60
Name the three ways of muslce metabolism.
- Creatine Phosphate
- Anaerobic Glycolysis
- Aerobic cellular respiration
61
What is an alpha motor neuron and what is a motor unit?
An alpha motor neuron innervates a muslce fibre. A motor unit is the motor neuron and all fibres it innervates.
62
Describe the three phase of a muscle twitch
Latent: muscle is stimulated and calcium is released
Contraction: myosin pulling way and casing sarcomere shorting
Relaxation: calcium removed
63
What is summation and tetany?
Summation: muscle is stimulated before is can relax
Tetany: condition where muscle cant relax as stimuli is too fast
64
Describe the properties of type one fibres
- slow myosin ATPase activity
- small diameter
- slow contraction
- fatigue resistant
- aerobic
- large capillary network
- high mitochondria number
- red
- minimal force
65
Describe the properties of type 2A fibres
- fast myosin ATPase activity
- medium diameter
- medium contraction
- fatigue resistant
- aerobic and anaerobic
- medium capillary network
- medium mitochondria number
- red
- medium force
66
Describe the properties of type 2B fibres
- fast myosin ATPase activity
- large diameter
- rapid contraction
- not fatigue resistant
- anaerobic
- small capillary network
- small mitochondria number
- white
- great force
67
What is the difference between isometric and isotonic contraction
Isometric is where tension increases with no length change
| Isotonic is the muscle changes its length without increasing tension
68
What are the tow divisions of isotonic contraction?
Concentric: muscle generates tension and muslce shortens
Eccentric: muscle generates tension and muslce shortens
69
What is Henneman's size principle?
Muslce motor units are recruited small to large
70
Where is insulin-growth factor found?
satellite cells, myofibres and Schwann cells
71
What is the function of IGF-1 after exercise?
Converts into mechano-growth factor and this increases protien synthesis
72
Describe myofibrilar hypertrophy (the one occurring in weight-lifters)
There is damage to the eccentric part of the myofibrils and this causes activation of satellite cells. The response is parallel addition of sarcomeres. This increases contraction and the cross-sectional area. The type of respiration involved is phoso-creatine.
73
Describe sarcoplasmic hypertrophy (the one occurring in body builders)
There is an increase in the extracellular water. The increase in metabolic stress causes an increase in lactate and hydrogen, and this increases the water. The aqua-porin 4 channels in fast-twitch fibres increase. Glycogen increases and every one gram of glycogen attracts three grams of water. This uses anaerobic glycolysis.
74
Describe the effects on endurance training
- decrease heart rate
- increased stroke volume
- increase mitochondria
- increase in glycogen and fat storing capabilities
- type one fibres develop
- increases myoglobin
- slow twitch hypertrophy
75
What is muscle fatigue?
A decline in muscle tension as a result of previous contractile activity.
76
Describe the two types of fatigue
High frequency fatigue: fibres will fatigue rapidly but recover fast. This is seen in high-intensity, short exercise.
Low frequency fatigue: this develop slowly and has a longer recovery period.
77
What three things decline with fatigue?
Force, shortening velocity and relaxation.
78
Describe the causes of high-intensity fatigue
- This is due to the failure of an action potential to be conducted along the T-tubule and thus no calcium is released. This is a result of potassium accumulation.
- Intracellular metabolite are also a cause as accumulation of ADP, Pi or H will be inhibitory. These inhibit calcium release and thus affect cross-bridge formation.
79
Why does high-intensity fatigue recover rapidly?
Potassium can diffuse out of the cells during rest.
80
CNS fatigue is a cause of endurance fatigue, Explain.
There is a psychological effect of central commands. The individual may stop even though the muscle hasn't fatigued.
81
Glycogen depletion is a cause of endurance fatigue, Explain.
Glycogen is a major energy source and is related to the carbohydrate intake. After 90% of glycogen has been used up, lipids are recruited. However, lipolysis only gives half the power glycogen gave.
82
Phosphate and ADP increase is a cause of endurance fatigue, Explain.
High concentrations will inhibit cross-bridges and calcium release.
83
Where about in muscle is Glycogen (from ingested carbohydrates) stored?
Muscle cytoplasm and liver. These stores are limited and may be depleted during long stores, especially with a diet of low carbohydrates.
84
When it is needed, Glycogen is transferred to glucose/ What enzymes carries this out and how does the glucose get across the membrane?
Calcium release causes the conversion through the enzyme glycogen phosphorylase.
There are GLUT 4 transporters.
85
Why does fat have 4x as more energy as carbohydrates?
Higher carbon ratio
86
What is fat broken down to in order for it to be allowed to be used for an energy source?
Triglycerides are broken down into fatty acid and glycerol. Only fatty acids are used.
87
What hormones activate the hormone sensitive lipases, which break down Triglycerides?
Adrenaline, Noradrenaline and glucagon.
88
What is the role of mitochondria in lactic acid?
Lactate is taken up by mitochondria and directly oxidised.
89
Describe the lactate shuffle.
Lactate produced by muslce can be transported else where. Lactate can be transported through diffusion or active transport. Lactic acid is mainly made in type two fibres but can be transported to type one.
90
What is the role of the liver with regards to lactic acid?
Lactic acid can be transported to the liver by blood and is converted to pyruvic acid and back to glucose. This is known as the cori cycle.
91
Describe how lactic acid can cause acidosis.
When lactic acid is not removed it will dissociate into hydrogen ions and lactate.
92
What is the process called that involves protien being converted to glucose?
Gluconeogenesi
93
Describe Neural growth, a process that occurs during strength training.
There is increased recruitment of largest motor units and firing rates
94
What is the difference between tennis and golfers elbow?
Golfers elbow is the media epicondyle and tennis elbow is the lateral epicondyle.
95
What are the functions of endoneurium, perineurium and epineurium?
- The endoneurium covers the axon
- The perineurium covers the fasciles
- The epineurium covers the nerve
96
What are the proprioceptors of muscle cells called?
Muscle spindles
97
What are the characteristics of an upper motor lesion?
- Spastic
- Hypertonic
- Hypereflexia
- disuse atrophy
- positive Babinski
98
What are the characteristics of an lower motor lesion?
- Flaccid
- Hypotonic
- Hyporeflexia
- Denervation atrophy
- negative Babinski
99
In the ASIA scale, what is the description of A?
This is complete. There is no sensory or motor function.
100
In the ASIA scale, what is the description of B?
This is incomplete. There is sensory but no motor function.
101
In the ASIA scale, what is the description of C?
This is incomplete. Motor function is preserved below neurological level and more than half of key muscles have muscle grade <3.
102
In the ASIA scale, what is the description of D?
This is incomplete. Motor function is preserved below neurological level and more than half of key muscles have muscle grade >3.
103
In the ASIA scale, what is the description of E?
This is normal.
104
Compare an contrast the development of skeletal, smooth and cardiac muscle
Skeletal muscle = originates from the paraxial mesoderm. Is formed when myoblasts fuse, under the influence of myf5 and MYOD, to form myotubes.
Smooth muscle = originates from the splanchnic mesoderm. However, ectoderm forms smooth muscle of pupil, mammary gland and sweat glands. Serum response factor is responsible for the smooth muscle cell differentiation.
Cardiac muscle = originates from the splanchnic mesoderm.
105
Where is the coronoid process located?
Ulna
106
In relation to the lateral epicondyle, where it the radial nerve and where is the posterior interosseous nerve?
Radial nerve: 2 fingerbreadths below
| Posterior interosseous nerve: 4 fingerbreadths below
107
The radial nerve gives of the posterior interosseous nerve and this supplies most of the wrist extensors. What two muslces does the radial nerve supply before branching into the posterior interosseous nerve?
Brachioradialis and Extensor carpi radialis longus
108
What tunnel does the ulnar nerve travel through, posterior to the medial epicondyle?
Cubital tunnel
109
What three muslces make up the Mobile wad of three?
Brachioradialis, Extensor carpi radialis longus and extensor carpi radialis brevis
110
What receptors become activated when a muslce action potential flows along an T tubule?
Ryanodine receptors. Their activation will cause calcium to be released.
111
What muscle does the ulnar nerve pierce?
Flexor carpi ulnaris
112
How are carbohydrates a muscle energy supply?
All carbohydrates are converted into glucose. During rest, ingested carbohydrates are stored in muslce in the form of glycogen. It is stored here until it is needed for ATP. These stores can be depleted if the diet is not sufficient or there is prolonged exercise.
Glycogen breakdown is stimulated by calcium increase by the enzyme glycogen phosphorylase.
113
How are fats a muscle energy supply?
Triglycerides have a higher carbon ratio and hence give more energy than carbohydrates do. Fat is less readily available as it is transformed from triglycerides into fatty acids and glycerol. Fatty acids can then undergo beta-oxidation.
114
What are the causes of high-intensity induced fatigue?
- failure of muslce action potential to be conducted down T tubule
- potassium accumulation, preventing action potential
- intracellular metabolite build up causing inhibition of calcium release
115
What are the three causes of endurance fatigue?
- CNS fatigue
- Glycogen depletion
- Metabolite build up
116
What type of hypertrophy is seen in weight-lifters?
Myofibrilar
117
What type of hypertrophy is seen in body-builders?
Sarcoplasmic
118
Explain the process of Myofibrilar hypertrophy
There is damage to the eccentric part of the muslce and this causes activation of satellite cells. This will cause parallel addition of sarcomeres and this increases both contraction and cross-sectional area.
119
Explain the process of sarcoplasmic hypertrophy
This is where there is an increase in extra-cellular water.
There is an increase in metabolic stress and this increases the amount of lactase and hydrogen. This increases water transfer.
There will be more aqua-porin 4 channels inserted and an increase in glycogen. Glycogen will increase water.
120
What are the three destinations for lactate?
- taken up by mitochondria and directly oxidised
- transported to another cell with a high concentration of mitochondria (lactate shuffle)
- transported to the liver and converted back into glucose
