Session 5 - Muscular And Motor Nervous System Flashcards
Name the 3 types of muscles
- Skeletal muscle
- Cardiac muscle
- Smooth muscle
What are the categories of skeletal muscles?
- Prime movers / agonists - responsible for movement
- Antagonists - oppose prime movers
- Synergists - assist prime movers
- Fixators - stabilise bones and neutralise unwanted movements
What are the generalised functions of skeletal muscles?
- They create movement by contracting
- They reduce the angle between articulating bones
What is the origin a muscle?
Its proximal attachment
What is the insertion of a muscle?
Its distal attachment
State the origin of the biceps brachii muscle
Apex of coracoid process of scapula - short head
Supraglenoid tubercle of scapula - long head
State the insertion of the biceps brachii muscle
Tuberosity of radius
State the nerve that innervates the biceps brachii muscle.
Musculocutaneous nerve
State the function of the biceps brachii muscle
It it the flexor and supinator of the forearm at the elbow.
State the origin of the coracobrachialis muscle
Apex of coracoid process of scapula
State the insertion of the coracobrachialis muscle
Linear roughening on the midshaft of the humerus on the medial side
Which nerve innervates the coracobrachialis muscle?
Musculacutaneous nerve
State the function of the coracobrachialis muscle
It is the flexor of the arm at the shoulder
Which muscles are located in the terror compartment of the arm?
- Biceps brachii
- Coracobrachialis
Which muscles are located in the posterior compartment of the arm?
Triceps brachii
State the origin of the lateral head of the triceps brachii muscle
Posterior surface of humerus
State the origin of the long head of the triceps brachii muscle
Infraglenoid tubercle of the scapula
State the insertion of the triceps brachii muscle
Olecranon of the ulna
Which nerve innervates the triceps brachii muscle?
Radial nerve
What are the functions of the triceps brachii muscles?
- Extension of he forearm at elbow.
- The long head extends and abducts the arm at the shoulder
Which muscles are located in the anterior compartment of the forearm?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
State the origin of the flexor carpi radialis.
Medial epicondyle of the humerus
State the origin of the flexor carpi ulnaris.
- Medial epicondyle of the humerus
- Olecranon and posterior border of ulna
State the origin of the medial head of the triceps brachii muscle
Posterior surface of humerus
State the insertion of the flexor carpi ulnaris
Pisiform bone and base of metacarpal 5
Which nerve innervates the flexor carpi ulnaris?
Ulnar nerve
What is the function of the flexor carpi ulnaris?
It flexes and adducts the wrist joint
State the insertion of the palmaris longus.
Palmar aponeurosis of hand
State the origin of the palmaris longus.
Medial epicondyle of humerus
Which nerve innervates the palmaris longus muscle?
Median nerve
State the function of the palmaris longus.
It flexes the hand
State the insertion of the flexor carpi radialis muscle
Base of metacarpals 2 and 3
Which nerve innervates the flexor carpi radialis?
Median nerve
What is the function of the flexor carpi radialis?
It flexes and abducts the wrist
Which muscles are in the posterior compartment of the forearm?
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor carpi ulnaris
- Extensor digitorum
Which muscles are in the anterior compartment of the thigh?
Psoas major
Iliacus
Vastus lateralis
Recuts femoris
Vastus medialis
Quadriceps femoris tendon*
What is the origin of the Psoas major muscle?
Posterior abdominal wall
State the insertion of the Psoas major muscle
Lesser trochanter of femur
Which nerve innervates the Psoas major muscle?
Anterior rami nerve
What is the function of the Psoas major muscle?
It flexes the thigh at the hip joint
State the origin of the Iliacus muscle
Iliac fossa in the posterior abdominal wall
State the insertion of the Iliacus muscle
Lesser trochanter of the femur
Which nerve innervates the Iliacus muscle?
Femoral nerve
What is the function of the Iliacus muscle?
It flexes the thigh at the hip joint
State the origin of the Vastus medialis.
Femur
State the insertion of the Vastus medialis
Quadriceps femoris tendon and medial border of patella
Which nerve innervates the Vastus medialis muscle?
Femoral nerve
What is the function of the Vastus medialis muscle?
It extends the leg at the knee joint
Where is the origin of the Vastus lateralis muscle?
Femur
State the insertion of the Vastus lateralis muscle.
Quadriceps femoris tendon and lateral margin of patella
Give the name of the nerve that innervates the Vastus lateralis muscle?
Femoral nerve
What is the function of the Vastus lateralis muscle?
It extends the leg at the knee joint.
Give the origin of the straight head of the Recutus femoris muscle.
Anterior inferior iliac spine
State the origin of the reflected head of the Rectus femoris muscle.
Ilium just superior to the acetabulum
State the name of the insertion of the Rectus femoris muscle.
Quadriceps femoris tendon
Which nerve innervates the Rectus femoris muscle?
Femoral nerve
List the names of the muscles in the posterior compartment of the thigh.
- Biceps femoris
- Semitendinosus
- Semimembranosus
Give the origin of the long head of the biceps femoris muscle.
Inferomedial part of the upper area of the ischial tuberosity
State the origin of the short head of the biceps femoris muscle.
Lateral lip of the linea aspera
State the insertion of the biceps femoris muscle.
Head of the fibula
Which nerve innervates the biceps femoris muscle?
Sciatic nerve
What are the functions of the biceps femoris muscle?
- Flexes leg at knee joint
- Extends and laterally rotates thigh at hip joint
- Laterally rotates leg at knee joint
State the origin of the semitendinosus muscle
Inferomedial part of the upper area of the ischial tuberosity
State the insertion of the semitendinosus muscle
Medial surface of proximal tibia
Which nerve innervates the semitendinosus muscle?
Sciatic nerve
What are the functions of the semitendinosus muscle?
- Flexes leg at knee joint
- Extends thigh at hip joint
- Medially rotates thigh at hip joint
- Medially rotates leg at knee joint
State the origin of the semimembranosus muscle
Superolateral impression of the ischial tuberosity
State the insertion of the semimembranosus muscle.
Medial tibial condyle
Which nerve innervates the semimembranosus muscle?
Sciatic nerve
What are the functions of the semimembranosus muscle?
- Flexes leg at knee joint
- Extends thigh at hip joint
- Medially rotates thigh at hip joint and leg at knee joint
Which muscles are in the adductor compartment of the thigh?
Adductor brevis
Adductor longus
Adductor magnus
State the origin of the Adductor longus muscle.
External surface of the body of the pubis
State the insertion of the Adductor longus.
Linea aspera on the middle of the shaft of the femur
Which nerve innervates the Adductor longus?
Obturator nerve
State the origin of the Adductor brevis.
External surface of the body of the pubis and inferior pubic ramus
State the insertion of the Adductor brevis muscle.
Posterior surface of proximal femur
Which nerve innervates the Adductor brevis?
Obturator nerve
State the origin of the adductor part of the Adductor Magnus muscle
Ischiopubic ramus
State the origin of the hamstring part of the Adductor Magnus.
Ischial tuberosity
What is the function of the muscles in the adductor compartments of the tight?
It is to adduct and medially rotate the thigh at the hip joint
List the muscles in the anterior compartment of the leg.
Tibialis anterior
Extensor digitorum longus
Peroneus tertius/Fibularis tertius
Extensor hallucinations longus
State the origin of the Tibialis anterior muscle
Lateral surface of tibia and adjacent interosseous membrane
Which nerve innervates the muscles in the anterior compartment of the leg?
Deep fibular nerve
Name the muscles in the posterior compartment of the leg.
Soleus
Gastrocnemius
List the muscles in the lateral compartment of the leg
Fibularis longus
Fibularis brevis
Which nerve innervates the muscles in the lateral compartment of the leg?
Superficial fibular nerve
Name the muscles in the muscle layer of the thorax
External intercostal
Internal intercostal
Innermost intercostal
What is the function of the external intercostal muscle?
Moves the ribs superiorly
What is the function of the internal intercostal muscle?
Moves the ribs inferiorly
Which nerves innervate the intercostal muscles?
Intercostal nerves; T1 - T11
Name the muscles in the muscle layer of the abdomen
External oblique
Internal oblique
Transversus oblique
Rectus abdominis
Describe the nerve supply of muscles in general.
Muscles of similar actions are innervated by the same nerves. Muscles are innervated by one motor neuron and it branches into the muscle fibres.
What is a motor unit?
The cell body, nerve fibre and all the muscle fibres supplied by a motor nerve
What is a prime mover?
Also called the agonist. It is the main muscle responsible for producing a specific movement of the body. It contracts concentrically to produce the desired movement.
What is a fixator?
A muscle that steadies the proximal parts of a limb through isometric contraction while movements are occurring in distal parts
What is a synergist?
A muscle that complements the action of a prime mover. It may directly assist a prime mover, providing a weaker or less mechanically advantaged component of the same movement, or it may assist indirectly, by serving as a fixator of an intervening joint when a prime mover passes over more than one joint.
What is an antagonist?
A muscle that opposes the action of another muscle.
List the types of muscle contractions
- Reflexive contraction
- Tonic contraction
- Physical contraction
What are the 2 types of tonic muscle contractions?
- Isometric
- Isotonic
What are the the 2 types of Isotonic contraction?
- Concentric contraction - muscle shortens
- Eccentric contraction - muscle lengthens
Name the factors that influence the strength of muscle contraction.
- Cross-sectional area
- Length of lever
- Force-length relation of a muscle
What is the influence of gravity on muscle action?
Gravity may be the prime mover e.g. addicting the upper limbs from the abducted position.
What is a neutraliser?
A muscle that neutralises unwanted movements caused by another agonist
What is a bursa?
A closed connective tissue pouch lined by synovial membrane that secretes synovial fluid. They reduce friction between muscles and other hard structures.
What are flat muscles?
They have parallel fibres often with an aponeurosis.
What are fusiform muscles?
Spindle-shaped with a round, thick belly and tapered ends
What are convergent muscles?
Muscles that arise from a broad area and converge to form a single tendon
What are quadrate muscles?
Muscles that have four equal parts
What are circular or sphincteral muscles?
Muscles that surround a body opening or orifice, constricting it when contracted.