Muscles Flashcards
What are the 3 types of muscles
Skeletal
Smooth
Cardiac
What are muscles made of?
Fibres
What do muscle fibres contain?
A myofibril
Where are skeletal muscles found?
attached to the bone via tendons
what attaches skeletal muscle to bones?
tendons
what is the function of muscles
Mobility Digestion Posture Communication Heat production Blood circulation Excretion
what are the 2 types of fibres in skeletal muscles?
Type 1 = slow twitch
Type 2 = fast twitch
What are type 1 skeletal muscles fibres for?
low intensity, high duration activities – i.e: marathons – they contract slowly but keep going for long time
What are type 2 skeletal muscles fibres for?
for high intensity, short duration – i.e: 100m sprint, Wilderbeast migration – red in colour, lots of blood vessels, good O2
Which 2 muscle types are striated?
Skeletal
Cardiac
Describe the structure of skeletal muscles
striped (striated), no obvious banding other than the stripes
Describe the structure of cardiac muscles
striped (striated), with obvious dark bands (intercalated discs), muscle fibres are branched
Describe the structure of smooth muscle
spindle shaped cells with a single nucleus - NOT striated
Where are smooth muscles found
Within many body systems - i.e: urinary, digestive, reproductive
And visceral structures - blood vessles, uterus, GI tract, bladder
Are smooth muscles contractions voluntary or involuntary?
Involuntary
What controls smooth muscles contractions?
Autonomic nervous system and hormones
What structure does smooth muscle lack?
Sarcomeres - but still contains actin and myosin
What is the arrangement of smooth muscles?
Overlapping cells in sheets or bundles
Name 3 functions of smooth muscle
Control blood flow around vessels Control air flow in resp. tract Control movement of food through GI tract Control reproductive tract (Uterus) Control urinary tract (bladder)
Where are cardiac muscles found?
In the heart
Are cardiac muscles voluntary or involuntary?
Involuntary
What does myogenic mean?
the muscles can contract and relax without receiving signals from the nervous system - it takes place in a rhythmic fashion
what is one adaptation of the cardiac muscle?
Has large amounts of mitochondria to provide masses of energy needed for tissue
What links the branches muscles cells of cardiac muscles?
Intercalated discs
what is the function of cardiac muscle
To make the heart beat
How are muscles stimulated?
Through nerve impulses that stimulate muscle fibres
What is the process of muscle stimulation?
Nerve impulses stimulate muscle fibres
stimulation is passed to sarcomeres via the sarcoplasmic reticulum
what are the 3 key molecules in muscles contraction?
Actin
Myosin
Calcium
What are the two types of actin ?
Tropomyosin
Troponin
What is actin?
Thin filament proteins to help muscle contraction
What is the structure of myosin
Thick, globular structures
What is the structure of tropomyosin
long proteins, found across actin strands
Where is myosin found?
In the middle of the sarcomere
in muscle contraction, where do calcium ions bind?
to troponin
which molecule breaks down ATP into ADP in muscle contraction?
Myosin
