Articular System, Muscular Anatomy Flashcards
Name the classifications of joints
Synovial, cartilaginous, and fibrous
Describe synovial joints and list examples
Freely movable (shoulder, hip, knee, elbow)
Describe cartilaginous joints and give an example
Slightly moveable (lower vertebrae)
Describe fibrous joints and give an example
Immovable (sutures in skull)
Name the joint types
Hinge, gliding, ball and socket, pivot, saddle, immovable
Describe a hinge joint and list some examples
The bones fit together like 2 parts of a hinge. Moves in 1 axis. (elbow, fingers)
Describe a gliding joint and give an example
The gliding surfaces are flat and the surfaces merely slide across one another (upper vertebrae)
Describe a ball and socket joint and list some examples
Ball shape of one bone fits into the socket shape of the other. Movements in all 3 axes. (shoulder, hip)
Describe a pivot joint and list some examples
One bone rotates around another. Moves in 1 axis. (radius/ulna, head/neck)
Describe a saddle joint and give an example
Freely moving joint like a saddle 2 axes. Oval head into a shallow cavity. (thumb)
What do tendons connect?
Muscle to bone
What do ligaments connect?
Bone to bone
What are tendons and ligaments?
Fibrous connective tissues made of collagen fibres.
Why are tendons, ligaments, and cartilage slow to repair?
They have poor blood supply.
What is cartilage made of?
Mostly protein
What are the characteristics of cartilage?
Firm (like bone), but still smooth and flexible.
Where is cartilage found?
- Joint surfaces of bones, where the smooth surfaces help prevent friction
- Menisci and intervertebral disks
- External ear and nose
List some common examples of tendons
- Achilles (between calves and calcaneus)
- Patellar (between quads and anterior tibia)
Give an example of a ligament
Anterior cruciate ligament (ACL) –>knee
What are the three types of muscle?
Smooth, cardiac, skeletal (striated)
What muscle type is under our conscience control?
Skeletal
Where is smooth muscle found and what does it do?
It lines the arteries and the gastrointestinal tract. It wraps around these vessels and helps in the peristaltic movements of the contents
Where is cardiac muscle found and what does it do?
It is only found in the heart. It can maintain its own rhythmic contractions.
What is skeletal (striated) muscle?
The muscles of motion
How does skeletal (striated) muscle work?
2 types of proteins interact to cause muscle shortening
What can training do for skeletal (striated) muscle?
It changes the characteristics of the muscle, increasing the amount of hypertrophy.
What is a muscle contraction?
A dynamic mechanical process involving the shortening of a muscle cell and the passive mechanical process involving the lengthening of a muscle cell.
What are the 2 basic types of muscle contractions?
Isometric (static) and isotonic
What happens in an isometric (static) contraction?
Tension is developed but there is no change in the external length of the muscle. It maintains stability.
Give an example of an isometric (static) contraction
Pushing against a wall
What is an isotonic contraction?
A normal contraction where the length of muscle fibres change.
What are the two types of isotonic contractions?
Concentric and eccentric
What happens in a concentric contraction?
The muscle shortens
What happens in an eccentric contraction?
The muscle lengthens
What type of contraction is more likely to result in injury? Why?
Eccentric because it is unusual work
What are the tree types of muscle fibre?
Type 1–> slow twitch, oxidative, red muscle fibre
Type 2b–> fast twitch, fast glycolytic, white muscle fibre
Type 2a-> fast oxidative glycolytic (FOG)
Type 1 muscle fibre is extremely oxidative. What does this mean?
They contain many mitochondria, which use oxygen to liberate energy. This means we are using our aerobic energy system.
What energy system are we using with type 1 muscle fibre?
Aerobic
What are the characteristics of type 1 muscle fibre?
- Smaller/thinner with smaller nervous pathways (resulting in slow reactions)
- Low force
- High endurance
- Extremely slow twitch
What is type 1 muscle fibre used for?
Any activity for prolonged time without break (long distance running and skiing)
What is fast twitch/fast glycolytic/white muscle fibre?
High force muscle fibre that fatigue very quickly.
Why is type 2b called fast glycolytic?
They liberate energy through the process of glycolysis, which does not use oxygen.
What energy system are we using with type 2b muscle fibre? Why?
Anaerobic because we don’t use oxygen to liberate energy.
What is type 2b muscle fibre used for?
High force activities for short periods of time (sprinting, jumping)
Why is type 2b muscle fibre also called white muscle fibre?
It does not change colours when stained for viewing under a microscope.
Why is type 1 muscle fibre also called red muscle fibre?
It turns red when stained for viewing under a microscope.
What does FOG stand for?
Fast oxidative glycolytic
What are the characteristics of type 2a muscle fibre?
- Both fast twitch and slow twitch responses
- Endurance type fibre
- Increased amount of force for longer periods
What is type 2a muscle fibre used for?
Activities that require increased force over a long time period (hockey, basketball, soccer)
What do the nervous pathways look like for each type of muscle fibre?
1 - small
2b - very large
2a - large but not as large as 2b
What are myofibrils?
Functional units containing groups of muscle cells/fibres
What is the sarcomere?
A bunch of myofibrils stacked together with similar end points
What are the endpoints of the sarcomere called?
Z lines
What do the myofibrils look like?
The are striated, meaning they are stacked end to end (they look striped)
What is sarcoplasm?
A liquid medium that the myofibrils are encased in. It contains many chemicals used for muscle contraction.
What protein filaments make up myofibrils?
Myosin and actin
What are actin bands?
Fixed structures attached to the Z lines
What are myosin strands?
Free-floating structures in between actin strands
What is the relationship between myosin and actin?
Myosin is attracted to the actin and wants to bind onto it, but the actin just doesn’t feel the same way :(
Why doesn’t the actin allow the myosin to bind?
The actin is covered with a substance called the T-T complex.
How does the myosin plan to bind with the actin?
The myosin has two heads or cross bridges that each look for a place to bind onto the actin.
How does the muscle contract if the T-T complex is covering the actin?
Skeletal muscle is voluntary. When our nervous system innervates a muscle, the electrical impulse changes the electro-chemical potential of the sarcoplasm. This changes the T-T complex. The myosin can now bind to the actin.
What happens when the myosin binds to the actin?
The Z lines are pulled together because they are attached to the actin, which closes the H band gap. This is contraction of the muscle.
How is muscle relaxed?
The brain sends a signal back to the muscle, which returns the chemical balance back to normal and the T-T complex makes the myosin let go of the actin.
What are the muscles of the scapular stabilization?
Trapezius, rhomboids, levator scapulae
Trapezius
O - base of skull, all cervical & thoracic vertebrae
I - superior part of scapula, lateral part of clavicle
A - moves scapula in various directions
Rhomboids
O - C7, T1-5
I - medial border of scapula
A - adduction of scapula towards midline
Levator Scapulae
O - cervical vertebrae
I - medial-superior border of spine of scapula
A - shoulder shrugs (elevation of scapula)
What are the muscles of the rotator cuff?
Supraspinatus, infraspinatus, teres minor, subscapularis
Rotator cuff
O - scapula
I - head of humerus
A - keeps humerus stable in joint, shoulder rotation
What are the muscles of the shoulder joint?
Deltoid, pectoralis major, latissimus dorsi, biceps brachii, triceps brachii
Deltoid
O - superior portions of scapula and clavicle
I - lateral portion of humerus (deltoid tuberosity)
A - abduction of humerus, horizontal flexion & extension
Pectoralis Major
O - anterior surface of clavicle, lateral edge of sternum
I - anterior-lateral portion of humerus
A - horizontal adduction (pushups)
Latissimus Dorsi
O - posterior part of ilium, lumbar vertebrae, lower thoracic vertebrae
I - medial side of humerus
A - adduction of humerus
Biceps Brachii
O - scapula
I - radial tuberosity
A - supination of hand
- elbow flexion
Triceps Brachii
O - upper - superior scapula
- medial - posterior surface of humerus
- lateral - posterior-lateral part of humerus
I - olecranon process of ulna
A - extension of elbow, extension of shoulder
What are the muscles of the elbow and radio-ulnar joint?
Biceps brachii, triceps brachii, brachialis, brachioradialis
Brachialis
O - lower anterior portion of humerus
I - anterior portion of head of ulna
A - elbow flexion
Brachioradialis
O - lateral part of lower humerus
I - lateral part of distal portion of radius
A - elbow flexion, pronation & supination of the hand
What are the hip flexors?
Sartorius and rectus femoris
Sartorius
O - anterior portion of ilium
I - anterior-medial condyle of tibia
A - flexion of hip, flexion of knee
Rectus Femoris
O - anterior portion of ilium
I - patellar tendon, which enters on the anterior portion of the tibia
A - flexion of hip, extension of the knee
What are the hip extensors?
Gluteus maximus, hamstrings
What are the hamstrings?
Biceps femoris, semitendinosis, semimembranosis
Gluteus Maximus
O - posterior-medial portion of ilium, near sacrum
I - posterior part of upper femur
A - hip extension, lateral rotation of hip
Biceps Femoris
O - inferior portion of ischium, middle of femur
I - lateral condyle of tibia and head of fibula
What actions do the hamstrings perform?
Hip extension and knee flexion
Semitendinosis
O - inferior portion of ischium
I - anterior-medial condyle of tibia
Semimembranosis
O - inferior portion of ischium
I - posterior-medial condyle of tibia
What are the knee flexors?
The hamstrings
What are the knee extensors?
The quadriceps
What are the quadriceps?
Rectus femoris, vastus lateralis, vastus intermedius, vastus medialis
Vastus Lateralis
O - lateral part of greater trochanter
Vastus Intermedius
O - middle part of greater trochanter of femur
Vastus Medialis
O - medial part of greater trochanter of femur
Where do the 3 vastus muscles insert?
Patellar tendon and patella, eventually to the tibia
What is the action of the 3 vastus muscles?
Knee extension
What are the foot plantar flexors?
Gastrocnemius, soleus
Gastrocnemius
O - posterior surface of the 2 condyles of the femur
I - achilles tendon, which connects to the calcaneus
A - plantar flexion of foot, flexion of knee
Soleus
O - upper posterior surface of tibia and fibula
I - achilles tendon to the cal calcaneus
A - plantar flexion of the foot
What muscle is responsible for foot dorsiflexion?
Tibialis anterior
Tibialis Anterior
O - anterior surface of tibia
I - superior part of metatarsals
A - dorsiflexion of the foot
What is included in the musculature of the torso?
Rectus abdominis, erector spinae, abdominal obliques
Rectus Abdominis
O - crest of pubis
I - cartilage of 5th-7th ribs, xiphoid process
A - flexion of trunk
Erector Spinae
O - posterior crest of ilium, posterior surface of sacrum, lumbar and thoracic vertebrae
I - joints between ribs and vertebrae, base of cranium
A - extension of trunk
Abdominal Obliques
O - lower 8 ribs
I - front half of crest of ilium, crest of pubis
A - flexion of trunk
Muscles work in perfect synchrony. What does this mean?
When one muscle contracts, the other relaxes, allowing bone to move.
What is the agonist?
- The prime mover
- The muscle or group of muscles producing a desired effect
What is the antagonist?
The muscle or group of muscles opposing the action.
What happens when entire groups of muscles are involved?
The interaction between agonist and antagonist muscles becomes more complex.
What are synergists?
- Muscles surrounding the joint being moved and supporting it in the action
- Compliment the action of the prime mover
What are fixators?
Steady joints closer to the body axis so that the desired action can occur.
