Lecture 5: How do we move? Flashcards
(32 cards)
What are the three types of muscle?
Cardiac
Smooth
Skeletal
What are myocytes?
Muscle fibres
What are fascicles?
Bundles of myocytes.
What are muscle fibres made from?
Many myofibrils.
What are myofibrils made from?
Many actin and myosin filaments.
What causes skeletal muscle to be striated?
The overlapping of actin and myosin microfilaments
Describe a muscle strain.
When muscle fibres become torn by over exertion.
Name the types of skeletal muscle. (5)
- Flat muscle
- Pennate muscle
- Fusiform muscle
- Quadrate muscle
- Circular/sphincter muscle
What is the muscle belly?
The collection of contractile muscle fibres.
What is the function of tendons?
To attach skeletal muscle to bone.
What is an aponeurosis?
A flattened tendon often associated with flat muscles.
Where do aponeuroses attach?
From muscle to soft tissue.
What is the initial point of attachment to bone of a skeletal muscle called?
The origin
What is the secondary point of attachment of a skeletal one to muscle called?
The insertion
What happens during contraction of skeletal muscle in terms of muscle fibres and insertions?
- The muscle fibres shorten along the long axis of the muscle.
- The origin and insertion approximate (Move closer together)
What are the three functions of the biceps brachii muscle?
- Flexion of the shoulder joint
- Flexion of the elbow joint
- Supination of the forearm
What four factors are required to determine the action of a muscle?
- Which joint(s) is/are spanned
- The long axis of the muscle fibres
- The aspects of the joint(s) that are spanned
- The shape of any articular surfaces that may limit movement.
What 5 aspects are used to name skeletal muscles?
- Latin greek description of muscle shape (E.g biceps=2 heads)
- The body region the muscle is located in (E.g brachii relates to arm (Brachial) region)
- The muscles relative size (E.g Major. minor, maximus, medius, minimus)
- Principle bony attachment of muscle (E.g tibialis anterior attaches to anterior aspect of the tibia)
- Principle movement produced by the muscle’s contraction. (Extensor digitorum extends the digits of the hand.)
Describe the five aspects used in physical examination of skeletal muscles.
- Inspection
- Palpation
- Passive movement to test muscle tone (I.e no resistance)
- Active movement against resistance to test power.
- Deep tendon reflexes with a tendon hammer.
What are reflexes?
Rapid, predictable, involuntary reactions to danger as a protective mechanism.
What are the two types of reflexes?
- Stretch reflex
- Flexion withdrawal reflex (Think touching something hot)
What is hypertrophy?
An enlargement in organ size without an increase in cell numbers.
What causes a muscle to become paralysed?
When the motor nerve supply to that muscle stops functioning.
What is meant by spasticity and what causes it?
When a muscle over contracts continuously, caused by the descending controls from the brain not functioning properly.
