Lecture 13- Muscle Tissue Flashcards
What is Myalgia?
Muscle pain
What is Myasthenia?
Muscle weakness
What is Myocardium?
Muscle component in the heart
What is Myopathy?
Any disease of the muscle
What is myoclonos?
Muscle spasm
Difference between Skeletal muscle and cardiac muscle
Skeletal- Direct nerve communication, multinucleated
Cardiac- Indirect nerve communication , 1 or 2 nuclei
Myogoblin?
Myoglobin has a higher affinity than haemogoblin and is a n oxygen storage molecule.
What is the sarcoplasm?
The cytoplasm of a muscle cell
Sarcosome?
The mitochondrian
What is a sarcomere?
Contraction unit in striated muscle
What is the sarcoplasmic reticulum?
The smooth endoplasmic reticulum of a muscle cell
What is the skeletal muscle structure?
Epimysium- surrounds multiple fasicles Perimysium- surrounds a singular fascicles Endomysium- wraps around muscle fibre Point of origin- tension created Point of insertion- movement
What are the muscle speeds?
Slow twitch- Rich in myogoblin, aerobic, rich capillary supply, fatty acid stores. Endurance activities. Lots of mitochondria, lots of cytochromes
Intermediate Twitch- Rich blood supply, aerobic, lots of myogoblin, many mitochondria, lots of cytochromes, fatty acids and glycogen Moderate activities- walking, standing
Fast twitch- Fewer myogoblin, anaerobic, poor capillary supply, glycogen storage , Few mitochondria, few cytochromes. For sprinting
Skeletal muscle Histology in Transverse and longitudinal
TS- Peripheral nucleus
LS- Nuclei in rows
What is cell hypertrophy?
Enlargement of their individual cells
What is cell hyperplasia?
Multiplication of their cells
What is the structure of smooth muscle cells?
No striations, spindle-shaped, single central nucleus.
Slower contraction, less ATP required.
Responds top stimuli: nerve signals, hormones
Ultra structure of smooth muscle cells?
Gap junctions connect adjacent smooth muscle cells.
How are smooth muscle cells innervated?
Innervated by the ANS fibres that release their neurotransmitters from varicosities into a wide synaptic cleft.
Conducting system of the heart
1) SA NODE receives STIMULUS and causes contraction of atrium
2) Pulse travels down the AV NODE AND stimulus goes to the bundle of Hiss
3) Goes down the PURKINJEE fibres and causes contraction of the bottom part upwards
4) Delay of signalling between nodes to allow fully pump the contraction in the cardiac muscle.
