Muscular System Flashcards
What are the 5 functions of muscle and explain each.
- Movement - a result of muscular contraction
- Maintaining Posture - stabilising joints, posture and balance through continued partial muscle contraction.
- Heat production - (Thermogenisis) Helping to maintain normal body temperature.
Shivering is described as involuntary contractions of the skeletal muscle. - Storage of substances such as Glycogen (long chain fatty acids) and Oxygen
- Movement of substances around the body e.g heart muscle pumping blood around the body.
Give five examples of muscle movement of substances around the body.
Heart - pumps blood around the body
Spincters - prevents out-flow from hollow organs
Smooth muscle in the blood vessels controls blood flow
Smooth muscle in the digestive tract moves food through and Urine in the urinary system.
Diaphragm - draws air into the lungs
What is a sphincter
a circular muscle
What does Thermo stand for
Heat
What does Genesis stand for
create
Name 4 muscle properties and what they do
Contractility - Ability to contract (shorten)
Excitability - Ability to create electric currents. Nerve impulses creates muscle contraction.
Extensibility - Allowing the muscle to stretch without damage.
Elasticity - Allowing the muscle to return to normal shape after contraction or extension. (spring)
Describe what Striated muscle cells look like and where do we find it.
Striated muscle cells are aligned in parallel bundles and is found in skeletal and cardiac muscle.
Describe what non striated muscle cells looks like and where is it found.
The cells are randomly arranged and is found in smooth muscle
How is striated muscle and non striated muscle seen under a microscope
Striated the stripes they form are visible. In non striated there are no stripes visible.
What are the 3 types of muscle and what are their key features
- Skeletal Muscle - Striated muscle, it attaches muscle to bone and permits movement at joints. It is a Voluntary muscle
- Cardiac Muscle - Striated muscle - forms the heart muscle only. Creates it’s own rhythmic contraction (autorhythmic). It is an involuntary muscle.
- Smooth Muscle - Non Striated muscle it is found in the walls of blood vessels, walls of the gut, Iris, stomach intestines and hair on the skin.
How many skeletal muscles do we have in our body
640
What percentage of our body weight do skeletal muscles account for?
40
What is Skeletal muscle covered in, what is it and what is it’s function?
It is covered in Fascia, it is a dense sheet of connective tissue that connects muscle to the skin, and provides a physical barrier around the muscle
What is a major component of Fascia
Collagen
Are skeletal muscles voluntary on involuntary?
Voluntary
What are the functions of skeletal muscles
Motion and posture, speech (larynx, lips, tongue) and breathing.
What does sarco mean
Flesh
What does plasm mean
meaning fluid
What does Myo mean
Muscle
What does Globin mean
Sphere/protein
What does Fibril mean
Relating to fibre
What else is a muscle fibre known as?
Muscle Cell
What is the name of a mature muscle cell and what are they formed from?
Myocytes and they are formed from immature cells called Myoblasts.
What is the name given to the cell membrane of skeletal muscle cells.
Sarcolemma
What is the equivalent to the Cytoplasm in Skeletal muscle cells.
Sarcoplasm
What are the tubes called that are found in muscle cells, where do we find them and what do they do?
Transverse Tubules - extend from the cell membrane into the muscle cells. They ensure that electrical impulses travelling along the muscle all get into the cell.
What Organelle do we find in abundant in skeletal and cardiac muscle.
Mitochondria
What is the organelle in Skeletal Muscle that stores calcium? Is this rough or smooth?
Sarcoplasmic Reticulum - It is smooth
Why do we need calcium in our muscles?
Calcium is needed for muscle contraction
What is the function of Myoglobin
Stores oxygen in muscles. This makes the muscle appear red.
Why do we need an abundance of mitochondria in our cardiac and skeletal muscles.
Because cardiac and skeletal muscle cells are metabolically active so require many mitochondria for energy in the form of ATP
What is skeletal muscle made up and how are they formed.
Made up of long cells called Myocytes (mature cells) that are formed by the fusion of lots of Myoblasts (Immature cells) in the embryo and they each have their own nucleus.
Can skeletal muscle fibres renew their cells. Explain
The number of skeletal muscle fibres each person has is set at birth. Once mature muscle cells are formed (becoming myocytes) they are no longer able to undergo mitosis. Muscle cells are able to grow in size but not in number. They have a limited regenerative capacity but the little they do have is done by satellite cells.
What are Myofibrils and how are they arranged?
Cylindrical structures formed of bundles of protein filaments within muscle fibre. They are contractile threads arranged in a striated pattern.
Myofibrils are made up of smaller filaments called xxxxxx
Myofilaments
What are the names of the 2 types of Myofilaments?
Myosin (Thicker filament)
Actin (thinner filament)
What to Myofilaments form?
They form sub units along the muscle called Sarcomeres’
What organelle are Myofibrils part of
Cytoskeleton
What is contraction of muscle on a cellular level referring too?
The sliding of Actin and Myosin Filaments
What is a sarcomere?
Basic unit of Striated muscle
What are the 4 areas of the sarcomere and describe each
H Zone - Myosin only
A Band - Dark area where Myosin and Actin overlap
I Band - light area of Actin only
Z Disc - filaments of actin that are arranged at 90 degree angles that separate the sarcomeres.
What do Myocytes contain
Myofibrils made up of smaller Myofilaments called Actin and Myosin
What does Mysium mean
Muscle connective tissue
Explain the structure of Myocytes
They are bundled together and surrounded by perimysium and form fascicles.
Fascicles accumulate together to form the entire muscle which is surrounded by the Epimysium.
The Epimysium provides an attachment for muscle to the periosteum of the bone.
What do collagen fibres do in muscle connective tissue do
It assists to tightly intermingle with other structures and apply forces in a very direct way.
What is the endomysium
a thin sheath that surrounds individual muscle fibres
What are fascicles and what surrounds them?
Bundles of between 10-100 muscle fibres that are bound together and they are surrounded by the Perimysium.
What is the muscle surrounded by and what does it do.
Epimysium - attaches the muscle to fascia and tendons.
What does endo describe
within
What does epi describe
upon or over
What does peri describe
around
What muscle raises the eyebrows?
What muscle closes the eyes?
Occipitofrontalis - Occ ip i toe
Orbicularis Oculi
What is the name given for chewing
Mastication
What are the 2 muscles called that are used for mastication?
Masseter and Temporalis
Name the 5 Muscles of the back where are each found and what is the function for each?
Suprapinatus - One of the rotator cuff muscles. - Initial abduction of the shoulder but only around 15%
Psoas - Anterior to the lumbar spine. Extends from the lower back through the hips and attaches to the femur. - Hip flexion (pulls the thigh towards the trunk)
Latissimus Dorsi - Widest muscle in the back that extends from the lumbar spine up the sides and attaches just beneath the shoulder muscle. - It extends, adducts and internally rotates the arms. Used for climbing or lat pull downs in the gym.
Quadratus Lumborum - attaches to 4 or the 5 lumbar vertebrae. Extends from the hip to the 12th rib. - Vertebral extension and lateral flexion (bending backwards or sideways)
Erector Spinale - Is a group of muscles that extend from the neck right through to the lumbar spine. - Extension of the vertebral column and keeps spine upright.
What muscle turns and tilts the head?
Sternocleidomastiod
Sterno = Sternum
Cleido = Clavical
Mastiod = mastiod process of the temporal bone (involved in chewing)
What muscle pulls head backwards and elevates (shrugs) and retracts shoulders
Trapezius
What is the major muscle of the chest, where does it attach and what is it’s function
Pectoralis Major - attaches from the clavicle and sternum to the humerous.
It’s function is to draw our arms forward. Shoulder Flexion and medial rotation
What are the names of the 2 stomach muscles, where are they attached and what is their function?
Rectus Abdominis -
Rectus - Fascicles running parallel to mid line and Abdominis meaning of the abdomen.
Runs from the lower sternum to the pubis.
Its function is for vertebral flexion (bending forward) crunches.
Internal and external Obliques - Used for rotation and bending sideways.
Where is the respiratory diaphragm found and what is it’s function.
It attaches to the six lower ribs and the lumbar spine. When it contracts it descends into the abdominal cavity increasing space for air to come into the lungs.
It also has vital structures passing through such as the aorta, internal vena cava, vagus nerve and Oesophagus.
What is the function of the Deltoid muscle and where does it attach.
Flexion abduction and extension of shoulder joint. It attaches from the scapular, acromion (bony edge of shoulder) and clavicle to the humerus.
Which is the muscle that stabilises the shoulder joint? What else does it do?
Biceps Brachii it stabilises the shoulder joint and flexion and supination of the forearm.
Which arm muscle is responsible for arm adduction and extending the elbow.
Triceps Brachii
Which muscle flexes the hand at the wrist joint?
Flexor Carpi muscle
What is the function of the the Extensor carpi muscle?
Extends hand at the wrist joint.
What does the Endomysium surround?
Individual Muscles cells/fibres
Name the Neurotransmitter at the Neuromuscular Junction
ACH (Acetylocholine)
Complete the sentence xxxxx and xxxxx are needed for muscle contraction?
Calcium and ATP
Complete the sentence xxxxx and xxxx are needed for muscle relaxation
Magnesium and ATP
Name the 2 Myofilaments
Actin and Myosin
Explain what is meant by muscle hypertrophy and atrophy?
Hypertrophy - Enlargement of size of the muscle
Atrophy - Loss of size of muscle
Compare aerobic respiration and anaerobic respiration
Aerobic respiration is in the presence of Oxygen and produces 36 ATP Molecules per glucose
Anaerobic respiration is absence of Oxygen and produces 2 ATP Molecules per glucose
Why do some muscles appear red?
Presence of Myoglobin
Indicate the type of cell respiration that slow oxidative muscle fibres use?
Aerobic
What ingredients do we need for effective muscle activity
Calcium, Magnesium, sodium, potassium and Iron
Why is sodium and potassium so important for effective muscle activity
Sodium and potassium allow the nerve impulse to arrive at the Neuromuscular Junction
Why do we need the presence of Iron for muscle hypertrophy?
Iron is needed to preform aerobic respiration
Iron carries Oxygen around the blood to the muscles and use this to create energy in the form of ATP
What hormones promote Hypertrophy
Growth Hormone
Testosterone
Thyroid hormones
When is growth hormone most active
In childhood for physical growth. It mainly happens at night hence why teenagers sleep so much.
What is Testosterone used for in muscles
Muscle development
What happens to muscles during strength training?
Individuals experience high levels of muscle tissue breakdown so protein is required to support hypertrophy.
The ability to produce ATP depends on the availability of nutrients such as…..
Glucose, fatty acids and amino acids
What are the 2 main pathways for ATP Synthesis
Aerobic Respiration or Anaerobic respiration
Aerobic respiration requires what to generate ATP
Oxygen that comes from breathing and a continual blood supply
In Aerobic respiration what does the chemical reaction produce?
38 ATP Molecules however 2 ATP molecules are used up in the reaction so we have a net of 36 molecules
Which organelles preform aerobic respiration in cells and where are they normally located?
Mitochondria often located next to the Myoglobin
Why would we use Anaerobic respiration?
Utilised for short term intense exercise
What is the name given to the breaking down of glucose?
Glycolysis
Where does Anaerobic respiration take place how? What does the reaction produce?
In the Cytoplasm and via Glycolysis. The reaction produces a net of 2 ATP Molecules
What Is the by product of anaerobic respiration and what can it cause?
It can cause muscle fatigue by producing lactic acid, which lowers the muscle PH causing the muscle fatigue
What is the equation for anaerobic respiration?
Glucose = Lactic acid + energy
Other than Aerobic and Anaerobic respiration, what is another way we can store energy?
Creatine Phosphate - this is a protein unique to muscles and is an energy storage form.
Why is Creatine Phosphate important
When muscles have very little energy in the form of ATP they can use creatine phosphate really quickly.
Creatine Phosphate provides a small, but ready source of energy during the first xxxxx of xxxxx
15 seconds of contraction
Compared to ATP how much creatine phosphate is there in a muscle cell?
3 to 6 times more creatine phosphate in a muscle cell
What is the by product of Creatine Phosphate? Where is it secreted from?
Creatinine is a by product from the breakdown of CPhosphate and is excreted by the kidneys.
What happens in Glycolysis?
Where we split a glucose molecule that we can then extract energy from.
Compare White and Red Muscle Fibres?
White -
Pale in colour due to the low quantity of Myoglobin
Fibres are larger in diameter
Use anaerobic respiration
Fatigue quickly due to fast and strenuous work.
Red Muscle fibres
Red due to the large quantity of myoglobin
Aerobic respiration (lots of mitochondria)
Fibres smaller in Diameter
Designed for sustained activity with no fatigue
What percent of muscle fibres are Slow Oxidative?
50%
What are the main muscle fibres in our arms and shoulders?
Fast Glycolytic (FG)
What are the main fibres found in the legs and back?
Slow Oxidative (SO) Fast Oxidative Glycolytic (FOG)
What fibres would we expect to find in Endurance Athletes?
Slow Oxidative fibres
What fibres would we expect to see for strength training
Fast Glycolytic (FG)
How do Skeletal muscles attach to bone?
Tendons attach muscles to the Periosteum of bone
What is the fleshy part of muscle called
Muscle Belly
What happen when muscle fibres contract?
Muscle becomes thicker and shorter. This exerts a force on the tendons which pull the bones producing a movement in the joint.
What is the location of muscle attachment to bones known as?
Muscle attachments
Muscle mechanics - how are most skeletal muscles arranged?
mainly in antagonistic pairs over a joint e.g biceps brachii/Triceps Brachii
Where do we commonly see muscle fatigue
Commonly seen in sports, occupational overuse and poor posture. Often individuals sat at desks with a poor posture.
What is muscle fatigue associated with?
Associated with a depletion of metabolic reserve. Cell respiration becomes anaerobic and by products that can cause pain, such as lactic acid
What is the best treatment for muscle fatigue
It is essential that we address poor posture and provide muscles with the time needed to rest. Meditation, Yoga, manual therapy, acupuncture, nutrition, homeopathy and herbs
Describe muscle shortening
If a muscle is continuously contracted the actin-myosin filaments remain attached.
What does chronic muscle contraction cause?
causes muscle fatigue but also puts strain on the skeletal muscle attachments
What is a muscle strain?
Overstretching of the muscle fibrils or the tendon, occurring when a joint is forced beyond it’s natural range. (pulled muscle).
The muscle remains whole and blood supply intact to permit healing.
What muscle strains are comman?
Leg and back
What is a muscle tear?
It is where the muscle tears and is no longer whole. More likely to cause bruising. A tear is suggested if movement is not possible.
A muscle tear can prevent natural complete healing. If so what can it lead too and what is it?
Can lead to Fibrosis which is thickening or scaring of the tissue.
