Muscle Tissue Flashcards
1
Q
What are muscle tissues specialized for and what are the three types?
A
- contraction
- skeletal, cardiac, and smooth
2
Q
What do muscle cells consist of?
A
- muscle cells (fibers)
- connective tissue elements (holds them tgthr and provides structure)
- blood vessels (capillaries) (travel thru muscle cells and provide nutrients)
- nerve/nerve endings (provide electrical basis for us to contract. Tell ourselves to contract or not)
3
Q
Skeletal Muscles
A
4
Q
Cardiac Muscles
A
5
Q
Smooth Muscles
A
6
Q
Functions of skeletal muscles
A
- produce movement of the skeleton
- maintains posture and body position (contracting even tho we aren’t doing anything)
- guards orifices (eyeball, mouth, anus, urethra)
- supports soft tissue
- maintains body temperature
7
Q
Muscles attach to other structures with tendons
A
- when attaching to bone, the tendon is woven into the periosteum of bone to form a strong bond
8
Q
Muscle fibers (cells)
A
- long, cylindrical, and multinucleated
- form a syncytium = single cell/cytoplasmic mass formed by fusion of cells
- muscle fiber = muscle cells
9
Q
Sarcolemma
A
- plasma membrane of muscle cells
10
Q
Sarcoplasm
A
- the cytoplasm of the muscle cells
11
Q
Myofibrils
A
- contractile fibers
12
Q
Where are nuclei found in a muscle cell?
A
- inside the sarcolemma
13
Q
T-tubules
A
- invagination of sarcolemma
- transmit membrane depolarization throughout sarcoplasm
14
Q
Sarcoplasmic reticulum
A
- muscles smooth ER
15
Q
Picture of skeletal muscle
A
16
Q
What are myofibrils made of?
A
- sarcomeres: smallest functional unit of a muscle fiber
- they repeat
- differences in the distribution of thick and thin filaments give them a banded appearance
- thick and thin = slide past each other to produce contractions
17
Q
Muscles are controlled by what?
A
- controlled by nerves in the CNS
- axon terminals connect to muscles at neuromuscular junctions
- look at slide for picture
18
Q
Motor unit
A
- a motor neuron, its axon, and all skeletal muscle fibers that it innervates
- few fibers innervated by single neuron = delicate movements, fine control. EX: playing piano
- more fibers innervated by single neuron = gross movements, less control. EX: expanding our spine to stand up
- picture = few fibers
19
Q
Atrophy
A
- muscles not repeatedly stimulated by a motor neuron lose tone and mass due to loss of contractile proteins
20
Q
Hypertrophy
A
- muscles that are repeatedly stimulated to produce near-maximum tension develop more myofibrils and mitochondria = enlargement
21
Q
Muscle organization
A
22
Q
Muscle organization pt. 2
A
23
Q
Muscle organization pt. 3
A
24
Q
Muscle organization pt. 4
A
25
Q
Muscle terminology
A
- origin: usually remains stationary
- insertion: usually moves
- action can be describes with regard to either the region affected by movement, or the joint involved
- flexion of forearm (region affected by movement)
- flexion of the elbow (joint that’s involved)
