Muscular system Flashcards
1
Q
Skeletal muscles attach to ____
A
Bones
2
Q
Where does the flexor carpi ulnaris insert?
A
Onto medial carpus
3
Q
What makes cardiomyocytes highly resistant to fatigue? Note - not required for LQB187 content
A
Cardiomyocytes have a high density of mitochondria that allows them to quickly produce ATP
4
Q
What is the name of the quadriceps tendon when it continues inferior to the patella?
A
Patella ligament
5
Q
Why are skeletal muscle cells multinucleated?
A
The fusion of many myocytes that forms each muscle fibre results in multinucleated cells
6
Q
Name some (general) regions of the body where tendons are common
A
Upper and lower limbs
7
Q
How many nuclei do smooth muscle cells have?
A
A single nucleus
8
Q
What is the function of smooth muscle?
A
- Involuntary movement
- Moves food
- Respiration control
- Moves secretions
- Regulated blood flow in arteries by contraction
9
Q
How much of body mass is made up of skeletal muscle?
A
40%
10
Q
What does contractility allow for muscles?
A
Allows muscles to pull on their attachment points and shorten with force
11
Q
Skeletal muscles perform voluntary movement and maintenance of ____
A
Posture
12
Q
What is the movement faciliated by muscles in the posterior compartment of the brachium?
A
Extension of the elbow joint
13
Q
What is the meaning of muscle tissue being ‘contractile’?
A
The tissue can shorten and generate a pulling force
14
Q
What prevents separation of cardiomyocytes during cardiac contraction?
A
Intercalated discs (the specialised junctions between cardiomyocytes)
15
Q
Are cardiomyocytes multinucleate?
A
Yes, they usually have one or two centrally located, oval shaped nuclei
16
Q
Describe the histology of smooth muscle (fibres, striations, and nuclei)
A
- Short and spindle-shaped
- No evident striation
- Single nucleus in each fibre
17
Q
What are skeletal muscle fibres comprised of?
A
Myofibrils bundled together by three layers of connective tissue
18
Q
What are tendinous intersections?
A
The three transverse bands of collagenous fibres that segment the rectus abdominis muscles
19
Q
Describe cardiomyocytes as they are typically found
A
Single cells, typically with a single centrally located nucleus
20
Q
What structures of a skeletal muscle contain dense regular connective tissue?
A
Tendons and/or aponeuroses (tendon-like variation of deep fascia that attaches sheet-like muscles that need a wide attachment area)
21
Q
The cardiac muscle pumps blood through the body and is under ____ control
A
Involuntary
22
Q
What segments the rectus abdominis muscles?
A
Three transverse bands of collagenous fibres called tendinous intersections
23
Q
What muscle feature is used to name the biceps brachii and the triceps brachii?
A
The number of muscle heads (AKA muscle bellies); ‘bi’ meaning two, ‘tri’ meaning three
24
Q
What is formed by the convex surface of the thoracic diaphragm?
A
The elevated floor of the thoracic cavity
25
What muscle structures are in the posterior compartment of the brachium?
The three heads of the triceps brachii
26
Name the muscle that crosses the glenohumeral and elbow joints to flex both joints
Biceps brachii
27
What the head flexes or extends, are the neck muscles acting unilaterally or bilaterally?
Bilaterally
28
For what are the involuntary contractions of cardiomyocytes responsible for?
Contraction of the heart, and therefore the distribution of blood around the body
29
Which type of muscles attach to bones?
Skeletal muscles
30
Where can smooth muscle be found?
Walls of major organs and passageways
31
Are cardiomyocytes typically found as single cells or fused together?
Single cells
32
Name three structures that have passage through openings in the thoracic diaphragm
- Descending aorta
- Inferior vena cava
- Oesophagus
33
Cardiomyocytes form long, ____ cardiac muscle fibres that are connected through ____ discs
Branching; intercalated
34
What does it mean to say that muscle tissue is excitable?
Muscle tissue responds to a stimulus
35
What is made possible by contraction of skeletal muscle?
Locomotion, facial expressions, posture, and voluntary movements
36
Describe the histology of skeletal muscle (fibres, striations, and nuclei)
- Long cylindrical fibres
- Striated
- Many peripherally located nuclei
37
Describe the structure formed by attached cardiomyocytes
Long, branching cardiac muscle fibres
38
Where do the muscular domes of the thoracic diaphragm insert?
Into the central tendon
39
Give two examples of a muscle named according to its relative size and length compared to others in its region
- Pectoralis major (larger)
| - Gluteus maximus (largest)
40
What are the three primary types of muscle tissue?
Skeletal, cardiac, and smooth muscle
41
How many heads does the pectoralis major have?
Two
42
What type of contraction is enabled by smooth muscle?
Involuntary
43
Give an example of a muscle named for its anatomical region or particular bone
Gluteus maximus (located in the gluteal region)
44
The muscles of mastication assist in the movement of what joint?
Temporomandibular joint
45
What do the inferior surfaces of the pericardial sac and pleural membranes fuse to?
The central tendon of the diaphragm
46
Where can skeletal muscle be found?
Attached to bones and around entrance points to the body (e.g. mouth, anus)
47
What does the deltoid allow?
Abduction, flexion, extension, and medial and lateral rotation of the glenohumeral joint
48
What is the large triangle-shaped muscle in the posterior neck and back?
The trapezius
49
What is facilitated by the thoracic diaphragm changing the volume of the thoracic cavity?
Breathing
50
Cardiomyocytes are adapted to contract without what?
Cardiomyocytes are adapted to contract without any stimulation
51
The direction of a muscle's fibres and fascicles describes the muscles in relation to what?
The midline
52
What movement does the head make when the neck muscles act bilaterally?
The head flexes or extends
53
What is the function of skeletal muscle?
- Voluntary movement
- Produces heat
- Protects organs
54
Is the superior surface of the thoracic diaphragm convex or concave?
Convex
55
Name the major abductor of the glenohumeral joint
Deltoid
56
What joint is flexed and adducted by the flexor carpi ulnaris?
The radiocarpal joint
57
The walls of hollow organs are often what kind of muscle?
Smooth muscle
58
How do skeletal muscle cells appear under a light microscope?
Striated with many nuclei squeezed along the membranes
59
The location of muscle heads is also the location of the muscle's ____
Origins/insertions
60
What type of muscle forms the contractile walls of the heart?
Cardiac muscle
61
Name the large muscle on the posterior neck and back
Trapezius
62
Describe the histology of cardiac muscle (fibres, striations, and nuclei)
- Short and branched fibres
- Striated
- One or two centrally located nuclei
63
Where are the nuclei generally located in skeletal muscle fibres?
At the periphery of each cell
64
Which type of muscle is made of non-striated muscle fibres?
Smooth muscle fibres
65
A muscle can return to its original length when ____
Relaxed
66
Why do skeletal muscle cells appear striated under a light microscope?
The regular alternation of the contractile proteins actin and myosin, along with the structural proteins that couple the contractile proteins to connective tissues
67
What are tendons?
Cord-like attachments composed of dense regular connective tissue that attach a skeletal muscle's fibres to relatively small areas on bone or cartilage
68
Where do the muscles in the anterior compartment of the antebrachium insert?
Onto different parts of the hand
69
What is used to describe muscles relative to the midline?
The direction of the muscle fibres and fascicles
70
Of skeletal, smooth, and cardiac muscle, which are excitable?
All three - their plasma membranes can change their electrical states from polarised to depolarised and send an electrical wave called an action potential along the length of the membrane
71
For which phase of breathing does the chest cavity expand?
Inhalation
72
How far do the rectus abdominis muscles extend?
Originate from the pubic symphysis and extend the length of the abdomen
73
What allows muscle tissue to pull on its attachment points and shorten with force?
Contractility
74
What shape is the thoracic diaphragm at rest?
Dome-shaped
75
What is the function of cardiac muscle?
Contracts to pump blood
76
The pectoralis major is associated with the movement of what joint?
Glenohumeral
77
How are the back muscles grouped?
According to the lengths and direction of the fascicles
78
What is produced asa by-product of skeletal muscle contraction?
Heat
79
Both sternocleidomastoid muscles working together are the ____ of the head
Flexors
80
Does the number of muscle cells vary widely over short times or remain relatively constant?
The number of muscle cells stays relatively constant throughout life
81
Name some of the origins of the muscular domes of the thoracic diaphragm
- The sternum (anteriorly)
- The inferior six ribs and their cartilages (laterally)
- The lumbar vertebrae and 12th ribs (posteriorly)
82
The appendicular muscles of the interior part of the body stabilise which structure?
The pelvic girdle
83
What is contraction of smooth muscle tissue responsible for?
Involuntary movements in internal organs
84
In what kind of locations (not specific) can smooth muscle be found?
The walls of hollow organs
85
Do individual skeletal muscle fibres lie parallel or perpendicular to each other?
Parallel
86
What enables a muscle to return to its original length when relaxed?
A quality of muscle tissue called elasticity that allows the muscle to recoil back to its original length
87
Where can cardiac muscle be found?
Heart
88
How many openings for the passage of structures between thorax and abdomen are there in the thoracic diaphragm?
Three
89
What are intercalated discs?
Specialised cell junctions between cardiomyocytes
90
Which muscle cells can respond to stimuli other than the nervous system, like hormones and local stimuli?
Cardiac and smooth muscle
91
Give an example of a muscle in the anterior compartment of the antebrachium
Flexor carpi ulnaris
92
Are the muscles in the anterior compartment of the antibrachium flexors or extensors?
Flexors
93
How many segmenting bands do the rectus abdominis muscles have?
Three each
94
Which cavities are separated by the thoracic diaphragm?
Thoracic and abdominal
95
What occurrence is a result of the facial expression muscles inserting in the skin rather than on bone?
When the muscle contract, the skin moves to create facial expression
96
What is the meaning of 'excitable' cells?
Their plasma membranes can change electrical states from polarised to depolarised and send an electrical wave called an action potential along the length of the membrane
97
Which muscle extends the radiocarpal and interphalangeal joints?
Extensor digitorum
98
What are the two categories of muscles?
Axial and appendicular (same as the skeletal system)
99
Is the inferior surface of the thoracic diaphragm convex or concave?
Concave
100
What is a principle characteristic of cardiomyocytes?
They contract on their own intrinsic rhythms without any external stimulation; they are capable of self-excitation
101
What is the major muscle that laterally flexes and rotates the head?
The sternocleidomastoid muscle
102
What muscles circle the anterior surface of the eye orbits?
Orbicularis oculi
103
What muscle changes the volume of the thoracic cavity?
Thoracic diaphragm
104
How are muscles named? There are six possible answers
By their shape, location, size compared to other nearby muscles, number of origins, action, or attachments to the skeleton
105
What is the proper term for a muscle cell?
Myocyte
106
When a muscle is named based on its attachments, what is named first?
The origin
107
What is shivering?
Involuntary contraction of skeletal muscles in response to perceived lower than normal body temperature
108
What is the major component of skeletal muscles?
Skeletal muscle fibres contained within the muscle belly
109
How many muscles are in the quadriceps femoris group?
Four
110
Movement of the temporomandibular joint is assisted by muscles of what action?
Mastication
111
What is the meaning of elasticity?
It can recoil back to its original length due to the presence of elastic fibres
112
What is the group of muscles in the anterior compartment of the thigh?
Quadriceps femoris group
113
Which type of muscles perform voluntary movement and maintain posture?
Skeletal muscles
114
Which type of muscle cell completely depends on signalling from the nervous system?
Skeletal muscle cells
115
Do cardiomyocytes fatigue?
Cardiomyocytes are highly resistant to fatigue
116
Give an example of a muscle named after its attachment to the skeleton
Sternocleidomastoid muscle (has origins on the sternum and clavicle, and inserts on the mastoid process of the temporal bone)
117
How do skeletal muscles participate in thermal homeostasis?
Skeletal muscles generate heat as a by-product of contraction
118
Which type of muscle tissue is made of non-striated muscle fibres that are thickest in the centre before tapering at the ends?
Smooth muscle fibres
119
Is skeletal muscle anucleated, nucleated, or multinucleated?
Multinucleated
120
What muscle is the largest of the gluteal group?
Gluteus maximum
121
Why is smooth muscle named 'smooth'?
The cells do not have striations
122
Where is the insertion of the patellar ligament?
Tibia
123
Where do most muscles that insert on the femur and move it originate?
On the pelvic girdle
124
Name the most anterior and superficial muscle of the quadriceps femoris group
Rectus femoris
125
What is the anatomical term for chewing?
Mastication
126
When the head rotates, are the neck muscles acting unilaterally or bilaterally?
Unilaterally
127
What is the effect of hypertrophy of the tendinous intersections of the rectus abdominis muscles?
'Six-pack ab' appearance
128
Are the muscles in the superficial posterior compartment of the antibrachium flexors or extensors?
Extensors
129
What muscle originates in the sternum and clavicle and inserts into the mastoid process?
Sternocleidomastoid muscle
130
What is the group of muscles that are some of the largest and most powerful in the body?
Gluteal group
131
Give an example of a muscle in the superficial posterior compartment of the antebrachium
Extensor digitorum
132
Where do the tendons of the extensor digitorum insert?
Digits 2 to 5
133
Name a muscle of facial expression
Orbicularis oculi (a circular muscle that encloses the eye)
134
What joins cardiomyocytes?
Intercalcated discs (specialised cell junctions)
135
List some of the minor structures in skeletal muscles
Areolar connective tissue, blood vessels and their epithelial lining, nerves, nerve receptors, and nerve endings
136
Skeletal muscle is attached to ____
Bones
137
What do cardiomyocytes do that allow the cells to synchronise their actions?
The cells form long, branching cardiac muscle fibres connected through intercalated discs
138
What muscle flexes and adducts the radiocarpal joint?
The flexor carpi ulnaris
139
Are cardiac muscle cells striated under a microscope?
Yes, cardiomyocytes are striated
140
What structure is common to all four muscles in the anterior compartment of the thigh?
The quadriceps tendon
141
Give an example of a muscle named according to the direction of its muscle fibres and fascicles
The rectus (straight) abdominis muscle
142
Give two examples of muscles named for the movement they produce
- Flexor carpi ulnaris (flexes the radiocarpal joint)
| - Extensor digitorum (extends the interphalangeal joints of the fingers)
143
How do cardiomyocytes attach to each another?
Specialised cell junctions called intercalated discs
144
How does the temporalis muscle assist with eating?
It retracts the mandible
145
Describe the nucleus of a smooth muscle myocyte
Centrally located, cigar-shaped nucleus
146
In what region is the pectoralis major located?
Thorax
147
Where are the muscular domes of the thoracic diaphragm?
To the sides of the central tendon
148
In which compartment are the muscles that flex the hip and extend the knee, anterior or posterior compartment of the thigh?
Anterior compartment of the thigh
149
For which phase of breathing does the chest cavity volume decrease?
Exhalation
150
What surrounds each skeletal muscle?
Dense irregular connective tissue, known as the deep fascia
151
What is prevented by intercalated discs during cardiac contraction?
Separation
152
Can the origin of a muscle move?
No
153
Skeletal muscle tissue is arranged in ____ surrounded by connective tissue
Bundles
154
What is allowed by the precise attachent of skeletal muscle fibres to bones/cartilage via tendons?
Production of fine motor movements
155
What movement is allowed by the attachment of the patellar ligament to the tibia?
Extension of the knee joint
156
What movement does the head make when the neck muscles act unilaterally?
The head rotates
157
What is the patellar ligament?
The inferior continuation of the quadriceps tendon past the patella
158
Where do the rectus abdominis muscles originate?
Pubic symphysis
159
What are the fibres of the muscle insertions of the facial expression muscles intertwined with?
Connective tissue and the dermis of the skin
160
In which compartment is the rectus femoris?
Anterior compartment of the thigh
161
What does 'extensibility' mean in regards to muscles?
The muscles can stretch or extend
162
Give some examples of involuntary contraction enabled by smooth muscles (there are two possible answers)
- Vasoconstriction (restricts blood flow)
| - Peristalsis (aids digestion and elimination of waste from the body
163
What is formed by the concave surface of the thoracic diaphragm?
The curved roof of the abdominal cavity
164
What feature of cardiac muscle allows the tissue of the heart to produce synchronised contractions?
The cardiomyocytes being branched and tightly joined by intercalated discs that prevent separation during contraction
165
____ muscle cells completely depend on signalling from the nervous system
Skeletal
166
Where do the muscles in the anterior compartment of the antebrachium originate?
On the humerus
167
What kind of tissue forms the deep fascia?
Dense irregular connective tissue
168
Name a muscle in the anterior compartment of the brachium
Biceps brachii
169
Which muscles lie anteriorly in the abdominal wall?
The rectus abdominis, a pair of long, linear muscles
170
Describe the two heads of the pectoralis major
Larger sternal head and a smaller, more superior clavicular head
171
Name a vessel located in the thorax but associated with movement of the glenohumeral joint
Pectoralis major
172
What structures fuse onto the central tendon of the thoracic diaphragm?
The inferior surfaces of the pericardial sac and pleural membranes
173
Of smooth, skeletal, and cardiac muscle cells, which one/s appear striated?
Skeletal and cardiac muscle cells
174
Which types of muscle cells can be influenced by the nervous system to some degree?
Cardiac and smooth muscle cells
175
What is the proper term for cardiac muscle cells?
Cardiomyocytes
176
What are cardiomyocytes?
Cardiac muscle cells
177
Which muscle covers much of the superior portion of the anterior thorax?
Pectoralis major
178
What are the structures to the sides of the central tendon of the thoracic diaphragm?
The muscular domes (the skeletal muscle portions of the thoracic diaphragm
179
Where is the insertion of the quadriceps tendon?
In the patella
180
Skeletal muscles perform ____ movement and maintence of posture
Voluntary
181
Which muscle is the major abductor of the glenohumeral joint, and facilitates flexion, medial rotation, extension, and lateral rotation?
Deltoid
182
Where are the origins of the muscles of facial expression?
On the surface of the skull
183
What shape are smooth muscle cells?
Spindle-shaped
184
In which compartment are the three heads of the triceps brachii?
Posterior compartment of the brachium
185
List some organs that have smooth muscle in the walls
Hollow organs:
- Urinary bladder
- Uterus
- Stomach
- Intestines
- Passageways (arteries and veins)
- Tracts of the respiratory, urinary, reproductive systems
186
Give two examples of terms that describe a muscle's shape
- Deltoid (triangle)
| - Orbicularis (circular)
187
What muscle is superficial to the temporal bone?
Temporalis
188
Muscle tissue is characterised by properties that allow ____
Movement
189
Involuntary movements in internal organs are the result of contraction of what kind of muscle?
Smooth muscle
190
What joints are extended by the extensor digitorum?
Radiocarpal and interphalangeal joints
