Physiology & Histology Flashcards
1
Q
What is the largest type of tissue in the human body?
A
Muscle
2
Q
Skeletal and cardiac muscles do NOT have striations. True/false?
A
False - only smooth muscle isn’t striated
3
Q
Skeletal muscles are innervated by which nervous system?
A
Somatic
4
Q
Cardiac & smooth muscle are innervated by which nervous system?
A
Autonomic
5
Q
Skeletal muscle contraction is initiated how?
A
Neurogenic (via NMJ)
6
Q
Cardiac muscle contraction is initiated how?
A
Myogenic (no NMJ)
7
Q
Skeletal muscle has gap junctions. True/false?
A
False (has NMJ)
8
Q
Cardiac muscle has gap junctions. True/false?
A
True
9
Q
In cardiac muscle, calcium for excitation coupling comes from where?
A
ECF and sarcoplasmic reticulum (c.f. skeletal which is ONLY from sarcoplasmic reticulum)
10
Q
What is the neurotransmitter at the NMJ?
A
Acetycholine
11
Q
What is a motor unit?
A
A single alpha motor neurone + all the skeletal muscle fibres it innervates
12
Q
Muscles which have fine movements tend to have more/fewer fibres per motor unit?
A
Fewer fibres per motor unit
13
Q
What is the functional unit of muscle?
A
Sarcomere
14
Q
Muscles are attached to the skeleton via
A
Tendons
15
Q
Actin is responsible for thick/thin filaments
A
Thin
16
Q
Myosin is responsible for thick/thin filaments
A
Thick
17
Q
Sarcomeres are located between two __ lines
A
Z-lines
18
Q
ATP is required for muscle _____ whule calcium is required for ______
A
ATP is needed for contracting & relaxing, while calcium is needed for switching on and off cross-bridge formation
19
Q
The surface of the muscle fibre extends through the sarcoplasmic reticulum across multiple myofibrils through which structures?
A
Transverse (T) tubules
20
Q
Graduation of skeletal muscle tension depends upon which 2 factors? (2)
A
1) Number of muscle fibres contracting within the muscle 2) Tension developed by each contracting muscle fibre
21
Q
Tension of each contracting muscle fibre depends upon which 3 factors (3)
A
-Frequency & summation of contractions -Length of muscle fibre at onset of contraction -Thickness of muscle fibre
22
Q
Can cardiac muscle become tetanised?
A
No, it has a dedicated refractory period
23
Q
What is isotonic contraction?
A
Used for body movements & moving objects - it’s when the muscle tension remains constant but the muscle LENGTH changes
24
Q
What is isometric contraction?
A
Used for supporting objects in fixed positions and maintenance of body posture. The muscle TENSION increases but the length remains the same
25
What are the 3 types of SKELETAL muscle fibres?
-Slow (Type I) -Fast oxidative (type IIa) -Fast glycolytic (type IIx)
26
In type I skeletal muscle fibres, how active is the myosin-ATPase activity?
Low
27
In Type IIa / IIx skeletal muscle fibres, how active is myosin-ATPase?
Highly active
28
How fast do type I muscle fibres contract?
Slow
29
What is the oxidative phosphorylation capacity of type IIx skeletal muscle fibres?
Low (they use anaerobic glycolysis to quickly make muscle)
30
Prolonged, relatively low-work aerobic activity is likely to be carried out mainly by which skeletal muscle fibre type?
Slow (type I)
31
Anaerobic metabolism and short, highly-intense activities are likely to be carried out mainly by which skeletal muscle fibre type?
Fast (type IIx)
32
A reflex is defined as...
A sterotyped response to a specific stimulus
33
Knee jerk reflex tests which spinal segments & nerve?
L3, L4. Tests femoral nerve.
34
Ankle jerk reflex tests which spinal segments & nerve?
S1, S2. Tests tibial nerve.
35
Biceps jerk reflex tests which spinal segments & nerve?
C5, C6. Musculocutaneous nerve
36
Brachioradialis reflex tests which spinal segmenets & nerve?
C5-C6. Radial nerve.
37
Which fibres sense muscle stretch?
Intrafusal muscle spindles
38
What's the efferent motor nerve supply to the infrasual fibres within muscle?
Gamma-nerves
39
Do intrafusal / spindle nerves contribute to overall muscle strength?
No
40
Immediate energy (e.g. for instant fast sprint for 4seconds) comes from which cellular source? What if this was increased to 15 seconds?
ATP first for around 3-4 seconds
Creatinine if prolonged to 15 seconds
41
What are the 3 sources of generating cellular energy?
1) Creaitnine 2) Oxidative phosphorylation (if O2 is present) 3) Glycolysis
42
Low-energy work (e.g. posture or walking) will generally utilise which type of skeletal fibre?
Type 1 (slow oxidative)
43
Moderate work (e.g. jogging) will generally utilise which type of skeletal fibre?
Fast oxidative (type 2A)
44
High intensity workouts (e.g. jumping) will utilise which skeletal muscle fibre?
Fast glycolytic (type 2x)
45
The speed of contraction of muscle is determined by activity of which enzyme?
Myosin ATPase
46
Describe skeletal muscle in terms of: striations absence/present, unbranched/branched, multinucleate/ single nucleus?
Striations present Unbranched Multinucleate
47
In skeletal muscle, the nuclei are present at the centre/ periphery?
Periphery
48
A group of muscle fibres is called a...
Fascicle
49
The connective tissue around a single fascicle is called...
Perimysium
50
The connective tissue around a single muscle fibre is called...
Endomysium
51
The connective tissue surrounding the whole muscle is called
Epimysium
52
In typical muscle, thousands of sarcomeres are placed end-to-end to form a...
Myofibril
53
Type 1 fibres have many/ few mitochondria?
Lots (very resistant to fatigue but slow to contract)
54
Is cartilage vascular?
No (cells are nourised from diffusion from the ECM)
55
The cells found inside cartilage are
Chondrocytes
56
The chondrocytes live within a space called a
Lacuna
57
ECM in hyaline cartilage is primarily made up of which 2 constituents?
1) Water (75%) 2) 25% organic material (type II collagen and proteoglycan aggregates)
58
Fibrocartilage contains which type of collagen?
Type I
59
Most common form of calcium phosphate in bone?
Hydroxyapatite
60
What type of bone is at the epiphysis?
Cancellous / spongy
61
Which type of bone makes up the diaphysis?
Cortical
62
What small pores on bone allow blood vessels to penetrate?
Haversion Canals
63
Which lines are found around osteons?
Cement lines (only if remodelling is present)
64
Cement lines are only present if what process has occurred in bone?
Remodelling
65
Which cell is responsible for bone remodelling?
Osteoclasts
66
Osteoblasts have lots of/ little RER?
Lots of
67
Osteoid is a collective name for?
The secretion of osteoblasts (contains collagen, GAGs, proteoglycans and other organic components)
68
The mineral of bone is primarily
Hydroapatite
69
Osteoclasts are believed to be derived from which cell?
Macrophage
70
What is normal: lamellar or woven bone?
Lamellar. Woven indicates fracture (haphazard collagen deposition)
71
Label the histological structures of muscle
A = Fascicle
B = Epimysium
C = Endomysium
D = Perimysium
72
What is the white canals running between muscle fibres here?
Perimysium
73
What does this section show?
Chondrocytes in lacunae
74
Label the bone histology structures
A = Osteon
B = Haversion Canal
C = Chondrocytes in lacunae
D = Volkmann's Canal
75
What do the red arrows indicate?
Cement lines (Areas where the bone has been remodelled)
76
Example of a fibrous joint
Skull
77
Does fibrous joints allow movement?
No (e.g. skull joints)
78
The intervertebral discs are made of which type of cartilage?
Cartilaginous (ampiathrosis)
79
The costochondral joints are what type of joint?
Cartilaginous
80
How thick is the synovial membrane in synovial joints?
Around 60 micrometers
81
The articular surfaces of bones are covered by
Articular (hyaline) cartilage
82
What is a compound articular joint?
An articular joint with more than one pair of articular surfaces (e.g. elbow joint)
83
What is a simple synovial articular joint?
A synovial joint with one pair of articular surfaces (e.g. phalanges)
84
Synovial fluid is adheisve, T/F?
True - allows free sliding between cartilaginous surfaces
85
Synovial fluid contains hyaluronic acid & lubricin, T/F?
True
86
The cartiage in joints is dry, T/F?
False - has an interstitial fluid
87
The adult knee contains approx what volume of synovial fluid?
\<3.5mL
88
The synovial fluid is static (i.e. not refreshed), T/F?
False - continuously refreshed by the synovial membrane
89
Viscosity varies how with joint movement? What effect does this have on elasticity?
Rapid movement decreases viscosity and increases elasticity
90
Normal synovial fluid should have how many cells per mm3?
\<200K per mm3
91
Septic synovial fluid is transparent/opaque?
Opaque
92
What are the zones of articular cartilage from top to bottom?
Superificial
Middle
Deep
Calcified
Subchondral zone
93
Articular cartilage is what type of cartilage?
Hyaline
94
Articular cartilage contains what type of collagen?
Type II
95
What are the effects of ageing on the cartilage? (2)
Decreased water content and decreased collagen content
96
Water content is highest where in the articular cartilage?
At the edges
97
Proteoglycan occurs mainly in which zone of the articular cartilage?
Middle Zone
98
Which compound in cartilage is responsible for its compressive properties?
Chondroitin sulfate (decreases with age)
99
Which enzyme class breaks down cartilage?
Metalloprotease
100
What effect does TNF alpha and IL-1 have on cartilage?
Lytic (catabolic)
101
What effect does TGF-beta and IGF-1 have on cartilage?
Growth (anabolic)
102
List 2 serum markers for cartilage degredation (2)
Keratin sulfate, type 2 collagen in synovial fluid. Both increased in conditions like OA.
103
What are the 3 pain types?
Nociceptive (adaptive), inflammatory (adaptive) and pathological (maladaptive)
104
Nociceptors are central/peripheral primary sensory afferents/efferents normally activated by intense stimuli.
Peripheral. Sensory afferents (relay pain sensation to the CNS).
105
What's the difference between 1st and 2nd order neurones? What type are nociceptors?
1st order relay information to 2nd order which relay it directly into the CNS. Nociceptors are first order neurones.
106
Nociceptive pain is high/low threshold and tends to override reflexes in a reflex known as the...
High threshold.
Withdrawal reflex
107
Is inflammatory pain adaptive?
Yes, a protective activation of immune system. Useful in pain such as wounds (prevents scratching/ reopening)
108
Pathological pain is protective, T/F?
False - it is maladaptive and represents a misfiring of the pain warning system
109
What subtype of nociceptor are responsible for first / fast pain?
Alpha-delta
110
Which type of nociceptor is responsible for slow/ delayed pain?
C-fibres
111
Why are there fast and slow pains?
Slow pain is carried in unmyelianted fibres (takes longer to reach CNS)
112
Where are all the pain nociceptors located?
Dorsal root ganglion or trigeminal ganglion
113
Peptidergic polymodal fibres are a subset of which pain fibre?
C-fibre
114
What is unique about peptidergic C-fibres?
They have both sensory afferent and an efferent function (contribute to inflammation by releasing substance P) which sensitises other nociceptors to pain
115
What is allodynia?
Non-painful stimuli causing the sensation of pain
116
What are primary & secondary hyperalgesia?
Hyperalgesia - increased pain sensation
Primary - in the area affected (e.g. skin under bite wound)
Secondary - around the area affected (e.g. around bite wound in the undamaged tissues).
117
What energy source will be used in exercise lasting \<4 minutes?
Free ciruclating glucose
118
What energy source will be used in prolonged exercise (up to 77 minutes)?
Glycogen
