Muscular System Flashcards
(57 cards)
1
Q
What are the two types of muscles that are striated?
A
skeletal and cardiac muscle
2
Q
What are the voluntary and involuntary controlled muscles?
* What is another name for voluntarily controlled?
* What is another name for involuntarily controlled?
A
- voluntary: skeletal
- involuntary: cardiac and smooth
- consciouslly and unconsiouslly
3
Q
The skeletal muscles are under control by what part of the NS?
A
somatic
4
Q
What muscles are controlled by the autonomic NS?
A
cardiac and smooth muscle
5
Q
skeletal muscles are attached to [_____]
A
bone
6
Q
What gives a muscle its striation?
A
- regularly arranged actin and myosin protein fibers
- alternating light and dark bands (light = just actin - I band; dark = myosin and actin- A band) in the sarcomere of muscle.
skeletal and cardiac muscle
7
Q
What is the muscle type that is NONstriated and why is that?
A
- smooth muscle
- SCATTERED actin and myosin rather than regularly arranged
8
Q
What are the 2 muscle types that generate STRONG contractions and what a WEAK contraction?
A
- 2 strong: skeletal and cardiac
- weak: smooth
striations allow for stronger contractions
9
Q
What allows for strong muscle contractions?
A
striations on muscle.
10
Q
Explain in general how movement is generated?
A
skeletal muscle contracts (shorten or lengthen), and it pulls the bone with it and moves the bone
11
Q
Give examples of where smooth muscles are found
A
- walls of visceral organs in GI (stomach, intestines), respiratory (bronchioles), urinary (bladder detrusor), reproductive tract (uterus myometrium, penile muscles ie. corpus cavernosum)
- blood vessel (arteriole) walls
- glands of smooth muscle
- skin arrector pilli muscle
12
Q
- How does vasodilation occur?
- How does vasoconstriction occur?
A
- dilation = relaxation of smooth muscle around arterioles
- constriction = contraction of smooth muscle around arterioles
13
Q
anatomy of skeletal m.
- Where are the 3 connective tissues located in the muscle?
- What is the specific name of this connective tissue?/ What is its function?
A
- epimysium: outer film of entire muscle
- perimysium: around each fasicle
- endomysium: around/between each muscle fiber / muscle cell
- muscle fascia- encloses, protects, supports, and separates muscle tissue
14
Q
- What is the contractile unit of the muscle?
- Where is it located?
A
- sarcomere
- myofibrils of muscle cell/ fiber
15
Q
organization of skeletal muscle from largest to smallest
A
- skeletal muscle
- bundles of muscle fascicles
- bundles of muscle fibers/ cells
- bundles of myofibrils
- contractile units of sarcomeres
16
Q
- What are the two protein filaments in a sarcomere?
A
- actin - thin
- myosin- thick
17
Q
What is the most basic of how muscle contraction occurs?
A
myosin pulls on actin, specifically toward midline (myosin slides past actin) to generate a force
18
Q
What are two substances required for muscle contraction?
A
- ATP- POWERS the contraction (releases myosin from actin to allow next power stroke to occur)
- Ca- allows myosin to bind to actin to do a power stroke
19
Q
What is the Z disc/ line?
A
separation between each sarcomere
20
Q
When the electrical impulse from the nerve tells the muscle to [_____], myosin heads attach to [______] and myosin [____] towards midline
A
- contract
- actin
- pulls actin
21
Q
What is the I band?
A
the area of the sarcomere with just actin= light stain
22
Q
What is the A band?
A
the area of the sarcomere with both actin and myosin = dark stain
23
Q
What is the H zone?
A
area of the sarcomere with just myosin
24
Q
What happens to the length of the sarcomere when there is an isotonic contraction?
A
shorter sarcomere
25
What is present in the NMJ (3 items)?
* pre-synaptic cell (LMN- alpha motor nerve- axon terminal)
* synaptic cleft with chemical neurotransmitters (Ach ALWAYS if it is a skeletal muscle)
* post- synpatic cell (muscle cell/ fiber motor end plate)
| motor end plate = folded part of sarcolemma
26
What is another name for muscle cell?
muscle fiber
27
What is the plasma membrane of a muscle fiber/cell called?
sarcolemma
28
What is the motor end plate?
folded part of the sarcolemma
29
Explain nervous system control of (skeletal) muscle contractions
1. nerve/ electrical impulse (AP from cell body in ventral horn of spinal cord to the axon terminal)
2. triggers Ca to go into axon terminal
3. triggers exocytosis of Ach from vesicles
4. Ach binds to nicotinic cholinergic receptors and this opens up voltage gated Na channels on sarcolemma
5. Na rushes into the muscle cell
6. sarcolemma cell membrane depolarizes (enough to membrane threshold)
7. muscle cell generates and fires an AP
8. AP travels along sarcolemma and down the **T tubules **into the muscle cell myofibril in both directions to **depolarize the ENTIRE muscle cell**
9. Ca channel in SR open up
10. **Ca go into** sarcoplasm of the muscle cell
11. cross bridge cycling at sarcomere
30
Name the electrical impulse and chemical impulse that is carried out by a neuron
* electrical: AP
* chemical: neurotransmitters (ie. Ach)
31
Ach binds to what type of receptors and where are those receptors found?
* cholinergic (nicotinic or muscarinic) receptors
* nicotinic - skeletal muscle
* muscarinic- cardiac and smooth muscle
| muscarinic receptors are dealing with the parasympathetic NS
## Footnote
nicotinic are dealing with the somatic NS
32
# nervous system
norepi binds
adrenergic receptors (alpha and beta) found on cardiac and smooth muscle
| adrenergic receptors are part of the sympahtetic NS
33
Explain the cross bridge cycle
* at rest aka muscle relaxed: actin and myosin ARE NOT bound together bc troponin on actin is in the way
1. **Ca** binds troponin, which allows **myosin to bind** to actin , meanwhile ADP is kicked ejected off myosin head and myosin does a power stroke
2. myosin is stuck on actin after the power stroke until ATP binds to myosin head
3. **ATP** binds to myosin head and **releases myosin** from actin [ ATP powers contraction]
4. hydrolysis of ATP on myosin head allows head to go back to be re-cocked for next contraction.
34
Explain the cross bridge cycle
* at rest aka muscle relaxed: actin and myosin ARE NOT bound together bc troponin on actin is in the way
1. **Ca** binds troponin, which allows **myosin to bind** to actin , meanwhile ADP is kicked ejected off myosin head and myosin does a power stroke
2. myosin is stuck on actin after the power stroke until ATP binds to myosin head
3. **ATP** binds to myosin head and **releases myosin** from actin [ ATP powers contraction]
4. hydrolysis of ATP on myosin head allows head to go back to be re-cocked for next contraction.
35
# skeletal muscle
Temporalis
allows for mastication (chewing) (CN 5 mandibular branch controlled)
36
# skeletal muscle
orbicularis oculi
allows for closing of the eyelid (CN 7 controlled) and blinking
37
# skeletal muscle
trapezius
* stabilizing, elevating the scapula
* back and shoulder movement
| test by asking to shrug shoulders (CN 11)
38
# skeletal muscle
Serratus anterior
* covers the ribs
* protraction (pulls scapula anterolaterally) and upward rotation of the scapula
39
# skeletal muscle
Biceps brachii
flexion and supination of the forearm
40
# skeletal muscle
Gracilis
flexes the knee, ADDucts thigh, medially rotate tibia on femur
41
# skeletal muscle
What are the three muscles of the quadriceps?
* recus femoris - thigh flexion
* vastus lateralis
* vastus medialis
42
# skeletal muscle
soleus and gastronemius
main plantarflexor of the foot
| gastronemius aka calf muscle
soleus: deep to gastronemius
43
# skeletal muscle
Tibialis anterior
primary dorsiflexor of the foot
44
# skeletal muscle
External Oblique
trunk flexion, expiration, trunk rotation
45
# skeletal muscle
Rectus abdominis
trunk flexion, expiration
46
# skeletal muscle
Pectoralis major
arm ADDuction, internal rotation, flexion/extension
47
# skeletal muscle
Deltoid
arm ABduction, flexion/extension, stabilization of shoulder joint
| common site for IM injection
48
# skeletal muscle
Sternocleidomastoid (SCM)
neck flexion/extension, rotation; elevation of clavicle and sternum
| CN 11 controlled
49
# skeletal muscle
Rhomboids
* covered by traps
* retract (bring scapula MEDIAL), elevate, and rotate the scapula
50
# skeletal muscle
Latissimus dorsi
works with pec major (and teres major) to ADDuct, internally rotate, and extend the arm.
51
# skeletal muscle
biceps femoris
one of the hamstring muscles
| others: semitendonous and semimembranous
52
# skeletal muscle
triceps brachii
extension of the forearm at the elbow joint
53
# skeletal muscle
gluteus medius
thigh ABduction and internal rotation
54
# skeletal muscle
gluteus maximus
extension and external rotation of the thigh at the hip joint
55
What is the function of the muscular system (3)?
* generate movement (skeletal muscle)
* circulate blood throughout the body (cardiac muscle)
* support and maintain posture
56
Describe the cells of the three muscle types
* skeletal m. --> long, cylindrical striated cells with some with more than 1 nucleus
* cardiac m. --> short, quadrangular cross striated cells with 1 nucleus
* smooth m. --> elongated spindle shaped cells
57
The **LENGTH** of actin and myosin do or do not change during a contraction?
DO NOT but the sarcomere length DOES (shortens)
