4.6 Muscles Flashcards
What are the characteristics of cardiac muscles?
Branched and striated interlaced discs
What are the characteristics of skeletal muscles?
Striated and unbranched
What are the characteristics of Smooth muscles?
Not striated
What does myogenic mean?
Muscles that never tire
What are the adaptations of muscles?
Many mitochondria
good blood supply
stores of glycogen
myoglobin
What is a sarcolemma?
Cell membrane of a muscle cell
What is a sarcoplasm?
cytoplasm of the muscle cell
What are microfibrils?
cylindrical packing of muscle fibres
What is a sarcomere?
one contractile unit
What is the thick microfibril called?
Myosin
What is the thin microfibril called?
Actin
In a sarcomere what is the light band called?
Z line
In a sarcomere what is the Dark band called?
M line
What occurs during contraction?
Thin (actin) slides between thick myosin filaments
sarcomere shortens
I band shortens
H zone shortens
A band remains same length
What is the process of excitation coupling?
Action potential penetrates whole muscle fibre
Ca channels open in sarcoplasmic reticulum
Ca diffuses into microfibrils and binds to trophin changing its shape
Tropomyosin is stimulated and exposes myosin binding sites on F-actin
Myosin heads from a cross bridge to actin
ADP releases from the head and myosin relaxes and rotates- pulling actin past myosin
ATP joins molecule and breaks the cross bridge
What are the characteristics of fast twitch muscle fibres?
Anaerobic
low mitochondria
low Blood vessel density
low myoglobin (Pale colour)
large glycogen stores
What leaver system is a bicep curl?
Third
What leaver system is looking down?
First
What leaver system is tip toeing?
second
What is the acronym for leaver systems?
F, L, E,
1,2,3
What is cartilage?
Smooth, hard elastic connective tissue
What are the functions of cartilage?
Shock absorber
Friction reduction
Structural support and shape maintenance
What cells make up cartilage? and whats the other fuction?
Chondrocytes
secrete proteins that make up extracellular matrix
What is the function of Hyaline cartilage, whats it strength and chondrocyte density and where is it found?
Helps bones move smoothly
Weak with medium density
ends of bones
What is the function of White fibrous cartilage, whats it strength and chondrocyte density and where is it found?
Holds parts in place
strong with low density
supporting tendons and muscles
What is the function of Yellow elastic cartilage, whats it strength and chondrocyte density and where is it found?
Allows bending and maintains shape
Medium strength and high density
Ears and nose
What are the functions of bones?
Protection
movement
support
mineral reserve
What are the types of bone? Where are they found?
Compact- central
spongey- end of bones
What is the function of osteoblasts?
To build new bone
What is the function of osteoclasts?
To break down bone
