1 Flashcards
(168 cards)
1
Q
What is the skeletal system?
A
A system of bony levers that provide support and protection.
2
Q
How many bones are in the body?
A
Approximately 206.
3
Q
What are the two divisions of the skeleton?
A
Axial and appendicular.
4
Q
What bones are part of the axial skeleton?
A
Vertebral column, coccyx, ribs, and sternum.
5
Q
What bones are part of the appendicular skeleton?
A
Shoulder/pectoral girdle, arms, wrists and hands, pelvic girdle, legs and ankles, and feet.
6
Q
What bones make up the vertebral column?
A
Cervical, thoracic, lumbar, and sacral vertebrae.
7
Q
What is the function of the vertebral column?
A
Provides support and allows movement.
8
Q
How many cervical vertebrae are there?
A
Seven (C1-C7).
9
Q
How many thoracic vertebrae are there?
A
Twelve (T1-T12).
10
Q
How many lumbar vertebrae are there?
A
Five (L1-L5).
11
Q
What are the five sacral vertebrae?
A
Fused together and make up the rear of the pelvis.
12
Q
What factors affect skeletal growth in adults?
A
Muscle use
13
Q
How can skeletal bone density be increased?
A
Heavy loading, explosive movements, frequency of loading axial skeleton
14
Q
What is required for effective long-term skeletal adaptations?
A
Varied frequency, intensity, and type of stimulus
15
Q
Do bones adapt faster than muscles?
A
No, bones take more time to adapt than muscles
16
Q
What are joints?
A
Junctions of bones in the skeleton.
17
Q
What are the three types of joints?
A
Fibrous, cartilaginous, and synovial.
18
Q
What covers the articulating ends of bones?
A
Smooth hyaline cartilage.
19
Q
What is the joint capsule filled with?
A
Synovial fluid.
20
Q
What are the additional supporting structures of joints?
A
Ligaments and cartilage.
21
Q
What type of movement do fibrous joints allow?
A
Virtually no movement.
22
Q
What type of movement do cartilaginous joints allow?
A
Limited movement.
23
Q
What type of movement do synovial joints allow?
A
Considerable movement.
24
Q
What is an example of a fibrous joint?
A
Sutures of the skull.
25
What is an example of a cartilaginous joint?
Intervertebral discs.
26
What is an example of a synovial joint?
Elbow and knee.
27
What are the characteristics of synovial joints?
Low friction, large range of motion, most movements occur about them.
28
What are the three categories of articulating joints?
Uniaxial, biaxial, multiaxial
29
What is an example of a uniaxial joint?
Elbows and knees
30
What is an example of a multiaxial joint?
Shoulder and hip ball-and-socket joints
31
What are the categories for muscle attachments?
Location-based
32
How are limb muscle attachments categorized?
Relative to midline
33
How are trunk muscle attachments categorized?
Relative to head position
34
What is a proximal attachment?
Limb muscle closer to midline
35
What is a distal attachment?
Limb muscle further from midline
36
What is a superior attachment?
Trunk muscle closer to head
37
What is an inferior attachment?
Trunk muscle closer to feet
38
What are skeletal muscles composed of?
Muscle tissue, connective tissue, nerves, and blood vessels.
39
What are tendons?
Fibrous connective tissue that attaches muscles to bone periosteum.
40
What is epimysium?
Outer connective tissue layer surrounding the muscle.
41
What are fasciculi?
Bundles of muscle fibers.
42
What is perimysium?
Middle connective tissue surrounding fasciculi.
43
What is endomysium?
Inner connective tissue that surrounds each muscle fiber.
44
What is sarcolemma?
Muscle fiber membrane contiguous with endomysium.
45
What is the diameter of muscle fibers?
About 50-100 micrometers.
46
What is the function of tendons?
To transmit tension developed in the muscle to the tendons and bone attachments.
47
What is the function of epimysium?
To cover every muscle in the human body.
48
What is the function of perimysium?
To surround fasciculi.
49
What is the function of endomysium?
To surround each muscle fiber.
50
What is the function of muscle fibers?
To group into bundles known as fasciculi.
51
What are muscles composed of?
Muscle fibers
52
What is the diameter of muscle fibers?
50-100 micrometers
53
What are the contractile components in muscle fibers?
Floating proteins
54
What are muscle fibers grouped into?
Fasciculi
55
What is the sarcolemma?
Muscle fiber membrane
56
What are myofibrils composed of?
Actin and myosin
57
What is the smallest contractile unit in a muscle?
Sarcomere
58
What forms crossbridges in myofibrils?
Pairs of myosin filaments
59
What regulates muscle contraction?
Calcium ions in sarcoplasmic reticulum
60
What are T-tubules?
Intricate system of tubules
61
Where do T-tubules terminate?
Near the Z-line between two sarcomeres
62
What delivers the signal from the motor neuron to all depths of the muscle fiber?
T-tubules
63
What is a sarcomere?
The smallest contractile unit in a muscle.
64
How are sarcomeres organized?
Based on areas containing myosin or actin.
65
What does the A-band correspond to?
Alignment of myosin filaments.
66
What does the I-band correspond to?
Area between two adjacent sarcomeres containing only actin.
67
What does the Z-line do?
Runs perpendicular to the I-band, separating each sarcomere.
68
What is the H-zone?
The center of sarcomeres that contains only myosin filaments.
69
What are motor units?
Motor neurons and muscle fibers they innervate
70
What are motor neurons?
Nerve cells responsible for innervating muscle fibers
71
What is the neuromuscular junction?
Junction between muscle fiber and motor neuron
72
How many neurons are responsible for innervating each muscle fiber?
Only one
73
How many muscle fibers can a single motor neuron innervate?
Hundreds or thousands
74
What is the 'all-or-nothing principle'?
All fibers in a motor unit contract simultaneously
75
What are the components of a motor unit?
Motor neuron, neuromuscular junction, muscle fibers
76
What is the sliding filament theory?
Theory of muscle contraction
77
What are the five phases of the sliding filament theory?
Resting, Excitation-contraction coupling, Contraction, Recharge, Relaxation
78
What happens during the resting phase?
Calcium stored in sarcoplasmic reticulum, few myosin crossbridges bound to actin
79
What happens during the excitation-contraction coupling phase?
Nervous system signals motor unit to contract, calcium released from sarcoplasmic reticulum, binds with troponin, H-zone and I-band shrink, Z-lines pull together
80
What happens during the contraction phase?
ATP on myosin crossbridge breaks down via hydrolysis, energy for pulling action delivered by breakdown of ATP into ADP and phosphate, known as power stroke
81
What happens during the recharge phase?
New ATP replaces ADP on myosin crossbridge, contractions repeat if calcium, ATP, and ATPase available
82
What is the enzyme that catalyzes the breakdown of ATP during the contraction phase?
Myosin ATPase
83
What is the power stroke?
Pulling action during muscle contraction
84
What happens during the relaxation phase?
Calcium is pumped back into sarcoplasmic reticulum, myosin crossbridges detach from actin, muscle returns to resting state
85
What is the role of troponin in muscle contraction?
Binds with calcium to initiate muscle contraction
86
What are the two categories of muscle fibers?
Fast twitch and slow twitch.
87
What is a motor unit?
Fibers of the same type.
88
What are slow-twitch fibers known as?
Type I fibers.
89
What are fast-twitch fibers known as?
Type II fibers.
90
What are the two types of fast-twitch fibers?
Type IIa and Type IIx.
91
What are the characteristics of Type I fibers?
Efficient, resistant to fatigue, high capillary density, high density of mitochondria, high capacity for using aerobic energy, low recruitment threshold.
92
What is the recruitment threshold of Type I fibers?
Lower than required for Type II fiber activation.
93
What is the potential for rapid force development and anaerobic power in Type I fibers?
Limited.
94
What is the endurance and fatigue resistance capacity of Type I fibers compared to Type IIa and Type IIx?
Greater.
95
What are the characteristics of Type II fibers?
Inefficient, rapidly fatigue, capable of rapidly producing force for short periods of time, significant anaerobic power.
96
What is the difference between Type IIa and Type IIx fibers?
Type IIa fibers have a greater capacity for aerobic metabolism and more capillaries than Type IIx making them more resistant to fatigue.
97
What are postural muscles?
Muscles with large composition of Type I fibers needed for endurance throughout the day. Example: Soleus.
98
What are prime mover muscles?
Muscles that include Type I and Type II fibers due to varying needs. The intensity of the activity will determine the relative involvement of fiber types. Example: Quadriceps group.
99
What are the two ways muscle force is graded?
Frequency of motor unit activation and increase in total number of activated motor units.
100
What happens when twitch frequency increases?
Muscular force increases.
101
What is tetanus?
A state of muscle activation where twitches merge together.
102
What are the adaptations to resistance training that improve force production?
Increased twitch frequency and increased numbers of activated motor units.
103
How can muscle force production in athletes be improved?
Incorporating phases of training with heavier loads, increasing muscle cross-section area, and focusing on explosive, multi-muscle, multi-joint exercises.
104
What are muscle spindles and Golgi tendon organs?
Specialized sensory receptors for proprioception
105
What information do proprioceptors provide?
Position of body parts with respect to gravity
106
How is proprioceptive information processed?
Subconsciously
107
What is the function of muscle spindles?
Provide information on muscle length and rate of change
108
What happens when muscle spindles are stretched?
Cause corresponding muscle fibers to contract
109
What is the function of Golgi tendon organs?
Provide information on muscle tension
110
Where are Golgi tendon organs located?
In tendons near myotendinous junction
111
What happens when the tendon attached to an active muscle is stretched?
Golgi tendon organs activate
112
What is the response of Golgi tendon organs to increased muscle tension?
Discharge increases and inhibits muscle tension
113
What is the function of inhibitory neurons stimulated by GTO discharge?
Reduce tension in the muscle
114
What is the possible function of GTO response?
Protect against excessive muscle tension
115
Can motor cortex signals override GTO response?
Yes
116
What is the overall effect of muscle spindle activation?
Increases activation in respective motor unit
117
What is the overall effect of GTO activation?
Decreases activation in respective motor unit
118
What is the function of intrafusal fibers?
Modified muscle fibers enclosed in a sheath of connective tissue
119
What is the function of extrafusal fibers?
Normal muscle fibers that run parallel to intrafusal fibers
120
What is the heart?
A muscular organ with two pumps
121
What is the function of the right side of the heart?
Pumps blood through lungs for oxygenation
122
What is the function of the left side of the heart?
Pumps oxygenated blood throughout the body
123
What are the chambers of the heart?
Right atrium, right ventricle, left atrium, left ventricle
124
What is the function of the right atrium?
Receives non-oxygenated blood from the body
125
What is the function of the right ventricle?
Pumps blood through the pulmonary circulation
126
What is the function of the left atrium?
Receives oxygenated blood from pulmonary circulation
127
What is the function of the left ventricle?
Pumps oxygenated blood through the body
128
What is the function of the tricuspid and mitral valves?
Prevent backflow of blood from ventricles into atria during systole
129
What is the function of the aortic and pulmonary valves?
Prevent blood flow from aorta and pulmonary arteries during diastole
130
What is the sinoatrial node?
Pacemaker of the heart, source of rhythmic electrical impulses
131
What is the atrioventricular node?
Delays impulse from the SA node to allow blood into the ventricles
132
What is the atrioventricular bundle?
Conducts impulse to ventricles via the left and right bundle branches
133
What are Purkinje fibers?
Further branching of the left and right bundle branches
134
What controls the rhythm of the heart muscles?
Medulla in the brain
135
What are the two nervous systems that transmit signals to the heart?
Sympathetic and parasympathetic
136
What effect does the sympathetic nervous system have on heart rate?
Increases heart rate
137
What effect does the parasympathetic nervous system have on heart rate?
Decreases heart rate
138
What is the typical resting heart rate range?
60 BPM to 100 BPM
139
What is bradycardia?
Heart rate fewer than 60 BPM
140
What is tachycardia?
Heart rate over 100 BPM
141
What is an ECG?
A graphical representation of heart's electrical activity.
142
What are the components of a normal ECG?
P-wave, QRS complex, T-wave.
143
What does the P-wave represent?
Atrial depolarization.
144
What does the QRS complex represent?
Ventricular depolarization.
145
What does the T-wave represent?
Ventricular repolarization.
146
What is atrial repolarization?
Repolarization of the atria.
147
What is hemoglobin?
Iron-protein molecule that transports oxygen and buffers blood pH
148
What is the function of red blood cells?
Contain hemoglobin and facilitate CO2 removal
149
What are arteries?
Large tubes that rapidly transport blood from the heart
150
What are arterioles?
Small tubes that branch off the arteries and control the blood before entering the capillaries
151
What are capillaries?
Smallest tubes that facilitate exchange of O2, CO2, and nutrients between blood and tissues
152
What are venules?
Collect blood from capillaries and transport it to veins
153
What are veins?
Larger tubes that return blood to the heart
154
What is the difference between the walls of arteries and veins?
Arteries have stiff walls to contain the high pressure of blood from the heart. Veins have thinner, dilatable walls that constrict or expand depending on the current needs of the body
155
What is the function of capillaries?
Facilitate exchange of O2, CO2, and nutrients between blood and tissues
156
What is the respiratory system?
Series of passages for gas exchange
157
What is the function of nasal cavities?
Warm, purify, and humidify air
158
What is the trachea?
First-generation respiratory passage
159
What are bronchi?
Second-generation respiratory passages
160
What are bronchioles?
23 generations of passageways to alveoli
161
What are alveoli?
Location of gas exchange in lungs
162
What happens during normal inspiration?
Diaphragm contracts, creating negative pressure
163
What happens during normal expiration?
Diaphragm relaxes, elastic recoil expels air
164
What muscles are used during heavy breathing?
Intercostals, sternocleidomastoids, anterior serrati, scaleni
165
What are pleural membranes?
Surround lungs with negative pressure
166
What is alveolar pressure?
Pressure inside lung alveoli
167
When does alveolar pressure fall?
During inspiration
168
When does alveolar pressure increase?
During expiration
