The Muscular System Flashcards
What does muscular tissue contribute to homeostasis
Body position, produces movement, regulates organ volume, moving substances within the body and producing heat
Almost all 700 individual muscles that make up the muscular system include both what
Skeletal muscle tissue and connective tissue
The function of most muscles is to produce what
Movement of body parts
A few muscles function mainly to stabilise the bones so that other skeletal muscles can execute what
Movement more effectiviley
What does the skeletal muscle do to move one of the articulating bones
Contracts
When the skeletal muscle contracts on two articulating bones one bone remains stationary, or near its original position. Why
Either because other muscles stabilise that bone by contracting and pulling it in the other direction, or because its structure makes it less moveable
Ordinarily the attachment of a muscles tendon to the stationary bone is called
The origin
The attachment of the muscles other tendon to the moveable bone is called
The insertion
The origin (attachment) of a tendon on the stationary bone is what to the attachment of the limb
Proximal
The insertion (attachment) of the muscle tendon on the moveable bone is what to the attachment of the limb
Distal
When a muscle contracts, the insertion is pulled towards the origin causing what to happen to the joint
Movement
The fleshy portion of the muscle between the tendons is called
The belly
Certain muscles are also capable of reverse muscle action (RMA) What does this mean
It means that specific movements are reversed, therefore, the positions of the origin and the insertion of a specific muscle are switched (ie a pull up on a bar)
What is the fixed point on a joint, on which a bony lever moves
Fulcrum
In producing movement, bones act as levers, and joints function as what
Fulcrums of the levers
A lever is a rigid structure that can move around a fixed point called a
Fulcrum
When the forearm is raised what is the fulcrum
The elbow
The weight of the forearm plus the weight of the object or resistance in the hand when raising the forearm it is called the
Effort
If you get a pair if scissors and try to cut a straightened paper clip with the tip of the scissor this is a mechanical what
Disadvantage
If you get a pair if scissors and try to cut a straightened paper clip nearer the pivot point of the scissor this is a mechanical what
Advantage
In leveraging systems and leverage, scissors and seesaws are examples of what class lever
First, EFL = effort, fulcrum, load
What class levers operate like a wheelbarrow
Second, ELF = effort, load, fulcrum
They always produce a mechanical advantage because the load is always closer to the fulcrum than the effort
What class lever operate like a pair of of tweezers
Third, FEL = fulcrum, effort, load
Skeletal muscle fibers (cells) within a muscle are arranged in bundles known as
Fascicles (FAS-I-kuls)
The muscle fibers are ? within a fascicle
Parallel
Fascicles, may form one of five patterns with respect to the tendons. What are they
Parallel
Fusiform (spindle-shaped, narrow towards the ends and wide in the middle
Circular
Triangular
Pennate (shaped like a feather)
Fascicular arrangement affects what in the muscle
Power and range of motion
What is the role of ligaments and joint capsules
They connect bone to bone
The marrow located in some bones produce what
Blood cells
An average of 2.6 million red blood cells are produced each second by bone marrow to replace those worn out and destroyed by which organ
The liver
Bones serve as a storage area for minerals such as calcium and phosphorus. When excess is present in the blood what happens
A build up will occur within the bones
When the supply of minerals such as calcium and phosphorus within the blood is low how is it replenished
It’s withdrawn from the bones
How is body movement carried out
By the interaction of the muscular and skeletal systems
How are muscles connected to the bones
By tendons
How are bones connected to each other
By ligaments
The bones of the appendicular skeleton are connected with one and other with what muscles
Skeletal
The appendicular skeleton includes the bones that make up the upper and lower limbs as well as what
The bones of the two girdles that attach the limbs to the axial skeleton
What is the significance of the pelvic axis
During childbirth the pelvic axis serves as the route taken by the baby’s head as it descends through the pelvis
What is the imaginary line that curves through the true pelvis from the central point of the plane of the pelvic inlet to the central point of the plane of the pelvic outlet
The pelvic axis
Out of the male and female which pelvis is wider and shallower
The female
Out of the male and female which pelvis is wider and shallower
The female
The bones of a male pelvis are narrower and deeper with more prominent markings for muscle attachment but also the bones are …………….. than the female pelvis
Larger and heavier
What is the longest, heaviest, strongest bone in the body
The femur (thigh bone)
Roughly how many muscles does the human body contain
650
When the muscles which connect two different bones contract what happens
there is movement of a joint
What three different types of tissues does the muscular system consist of
Skeletal, cardiac, smooth
What are the two main types of muscles in the muscular system
Voluntary and involuntary
What type of muscles are we in control of
Voluntary
What are the muscles that are beyond conscious control
Involuntary ie the heart
What is an intramuscular injection
An injection that penetrates the subcutaneous layer to enter the muscle itself
What is deep fascia (intermuscular septum)
It separates the muscles of the thigh that act on the femur and tibia and fibula into medial, anterior and posterior compartments
Most muscles of the medial (adductor) compartment of the thigh have a similar orientation and adduct the femur at what joint
The hip
What is the largest muscle in the body, covering most of the anterior surface and sides of the thigh
Quadriceps femoris
What is the common tendon for the quadriceps
Quadriceps tendon
Which muscle of the medial compartment of the thigh, a long strap like muscle on the medial aspect of the thigh and knee, adducts the thigh and medially rotates the thigh and flexes the leg at the knee joint
The gracilis
Muscles of the anterior (extensor) compartment of the thigh that extend the leg (and flex the thigh)
Quadriceps femoris and sartorius muscles
The quadriceps femoris muscle is a composite muscle, usually described as four separate muscles. These are called
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
The quadriceps tendon inserts into the patella which then continues below the patella and is called what ligament
Patellar ligament which attaches to the tibial tuberosity
The muscle which is the great extensor muscle of the leg is called
Quadriceps femoris
The muscle that is long and narrow that forms a band across the thigh from the ilium of the hip bone to the medial side of the tibia is called
The sartorius
What muscle produces flexion of the leg at the knee joint, abduction, and lateral rotation at the hip joint to help effect the cross-legged sitting position in which the heel of one leg is places on the knee of the opposite limb.
Sartorius (its name means tailors muscle)
Where are the muscles of the compartment of the thigh that flex the leg and extend the thigh
Posterior (flexor)
What are the component muscles of the posterior (flexor) compartment of the thigh
Hamstrings
Biceps femoris
Semitendinosus
Semimembranosus
What two joints do the hamstrings span
Hip and knee
What posterior muscles are extensors of the thigh and flexors of the leg
Hamstrings
What is the diamond shaped space on the posterior aspect of the knee
Popliteal fossa
Lateral to the tibialis anterior muscle is a feather like muscle, where it can be palpated easily called
Extensor digitorum longus muscle
What muscle which is part of the extensor digitorum longus and shares the same origin, helps extend the foot and turn it outward
Fibulalaris tertius muscle
What muscle makes up the wall of the heart
Cardiac
Why is the cardiac muscle different to other types of muscles
Because it has branching fibres
What muscle is not attached to bones
Cardiac
The skeletal muscle makes up what percentage of an adults body weight
40%
What are skeletal muscles composed of
Long muscles fibres
Each of the skeletal muscle fibres is a cell which contains several what
Nuclei
Many of the skeletal muscles are automatic , however we can still control the action so these muscles are called
Voluntary muscle
The internal organs are made up of what muscles
Smooth
Where are smooth muscles found
Urinary bladder
Gallbladder
Arteries
Veins
Digestive tract
The nervous system and hormones control what muscles
Smooth
Smooth muscles cannot consciously be controlled, therefore they are what muscles
Involuntary
What does skeletal muscle consist of
Muscle tissue
Connective tissue
Nerves
Blood vessels
What is the fibrous fascia called that covers each muscle and tendon
Epimysium
What is the connective tissue that covers all bones
Periosteum
What is the connective tissue covering the bones that the tendon connects the muscle belly to
Bone periosteum
When the muscle contracts the belly/body pulls on the tendon and the bone it is attached to what happens
The bone moves
What is the muscle belly made up of
Muscle cells or fibres
Roughly how many fibres are grouped into a bundle (fasciculi)
150 fibres
What is a muscle fibre bundle called
Fasciculi
What is the connective tissue that surrounds a fasciculi (fibre bundle)
Perimysium
What is the connective tissue that the muscle fibres in the fasciculi are surrounded by
Endomysium
Each individual muscle fibre consists of a membrane called
Sarcolemma
The membrane that the muscle fibres consists of is called
Sarcolemma
Sarcolemma the membrane of muscle fibres can be broken down into hundreds or even thousands of
Myofibrils
What make up the contractile components of a muscle
Myofibrils surrounded by sarcoplasm
A muscle whose contraction moves a limb or other part of the body towards the midline
Adductor
A muscle whose contraction moves a limb or other part of the body away from the midline
Abductor
A muscle whose contraction extends or straighten a limb or other part of the body
Extensor
A muscle whose contraction bends a limb or other part of the body
Flexor
The movement of bending the foot upwards, bringing the toes closer to the shin is called
Dorsiflexion
What is the opposite of dorsiflexion
Planterflexion, the movement of the foot in a downward motion away from the body
Abductors (tensor fasciae latae, gluteus medius, gluteus minimums) - what is the a: origin, b; insertion and c: action
A: Ilium
B: Femur
C: Brings hip away from body
Adductors (includes adductor Longus, adductor breves, adductor magnus gracilis muscles)
A: origin
B: insertion
C: action
A: pubis
B: medial surface of body of tibia
C: adducts thigh at hip joint, medially rotates the thigh, and flexes leg at knee joint
Gluteus maximus
A: origin
B: insertion
C: action
A: ilium
B: femur
C: extension of the hip joint, supports the extended knee, helps with sitting, running, helps stabilize the pelvis and trunk, especially when standing on one leg
Hamstrings (made of 3 muscles), biceps femoris, semitendinous, semimembranos
A: origin
B: insertion
C: action
A: ischium
B: tibia, fibula and pes anserinus
C: bends knee
Iliopsoas
A: origin
B: insertion
C: action
A: lumbar vertebrae and ilium
B: femur
C: hip flexes, hip rotation and trunk flexion
Quadriceps (made of 4 muscles) : rectus femoris, vastus lateralised, vastus medialis and vastus intermedius
A: Origin
B: insertion
C: action
A: ilium and femur
B: tibia (patella tendon)
C: extends knee
Gastrocnemius (calf muscle)
A: origin
B: insertion
C: action
A: femur
B: calcaneum (by Achilles tendon)
C: flexes the ankle and knee
Soleus (calf muscle)
A: origin
B: insertion
C: action
A: fibula and tibia
B: calcaneus
C: planter flexes the foot
Tibialis anterior
A: origin
B: insertion
C: action
A: Tibia
B: first metatarsal and medial cuneiform
C: dorsiflexes the ankle and inverts the foot
What is the muscle tissue called that makes up the wall of the heart
Cardiac
What is the cardiac muscle of the heart called
Myocardium
Skeletal muscles and cardiac muscle are striated and contract through a sliding filament method but hoe is the cardiac muscle different
Because it has branching fibres and is not attached to bone
What % of skeletal muscles does it make up in an adults body weight
40%
What are skeletal muscles composed of
Long muscle fibres which is a cell containing several nuclei
What system in the body controls the contraction of the muscle
The nervous system
Many off the skeletal muscles are automatic however we still can control the action of the skeletal muscles. So are they called voluntary or involuntary
Voluntary
What type of muscle are the internal organs made up of
Smooth muscles
What body system controls the smooth muscles
The nervous system and hormones
Smooth muscles found in the urinary bladder, gallbladder, arteries, veins and also the digestive tract are voluntary or involuntary
Involuntary
Muscles of the anterior compartment of the leg
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius
Muscles of the lateral compartment of the leg
Fibularis longus
Fibularis brevis
Muscles of the superficial posterior compartment of the leg
Gastrocnemius
Soleus
Plantaris
Muscles of the deep posterior compartment of the leg
Popliteus
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus
Muscles of the medial (adductor) compartment of the thigh
Adductor Magnus
Adductor longus
Adductor brevis
Pectineus
Gracillis
Muscles of the anterior (extensor) compartment of the thigh
Quadriceps femoris
Rectus femoris
Vastus lateral is
Vastus medialis
Vastus intermedius
Sartorius
Muscles of the posterior (flexor) compartment of the thigh
Hamstrings
Biceps femoris
Semitendinosus
Semimembranosus
Myofibrils encase two types of protein filament called
Myofilaments
What are the two types of protein filaments or myofilaments that the Myofibrils encases
Actin
Myosin
Myosin has tiny globular heads protruding rom it at regular intervals called
Cross bridges
What plays a pivotal role in muscle action
Cross bridges, the tiny globular heads protruding from myosin
What are the organised sections (a structural unit of muscle) that each Myofibril has along its length and are repeated right along the length of the muscle fibre and is located between two adjacent z-lines
Sarcomere
What is the smallest contractile portion of the muscle fibre
Sarcomere
What are the lines that are dense structures that anchor thin (action) filaments and separates each Sarcomere
Z-lines
What zone is the centre of the Sarcomere
H-zone
What line in a Sarcomere is where adjacent myosin filaments anchor on to each other
M-line
In a Sarcomere what bands are where adjacent myosin filaments align
A-bands
In a Sarcomere what bands are where adjacent myosin actin filaments align
I-bands
When muscle contracts the z-lines are pulled towards each other and the H-zone and I-band both what
Decrease
The myofilament sliding theory states that muscle fibres shorten when actin filaments slide inward on myosin filaments so what happens to the z-lines
They get pulled closer together
When the cross bridges (tiny globular heads contained in a myosin filament) attach to the actin filaments pulling on them they create what
Movement
Each flexion of a cross bridge (myosin) produces only a very small movement in the actin filament so for any measurable movement to occur the muscle must flex how
Repeatably and rapidly
What do the myosin cross bridges need to do for the contraction to continue
Recock and reattach
The lateral compartment of the leg contains two muscles that plantar flex and evert the foot
Fibularis longus
Fibularis brevis
The muscles of the leg, like those of the thigh, are divided by deep fascia into what three compartments
Anterior
Lateral
Posterior
What is the upward bending of the hand or foot
Dorsiflexion
What do the muscles of the anterior compartment of the leg do to the foot
Dorsiflex it
The tendons of the muscles of the anterior compartment are held firmly to the ankle by thickenings of deep fascia called
Superior extensor retinaculum (transverse ligament of the ankle)
And
Inferior extensor retinaculum (cruciate ligament of the ankle)
In the anterior compartment of the leg the extensor hallucis longus is a thin muscle between and partly deep to the tibialis anterior and what other muscle
Extensor digitorum longus
Within the anterior compartment of the leg is a long thick muscle against the lateral (side) surface of the tibia, where it is easy to palpate (feel), which is called the
Tibialis anterior
