Lecture 10 and 11(muscles) Flashcards
List the 4 unique properties of muscle tissue
Excitability
Contractility
Elasticity
Extensibility
Explain excitability
Muscle cells are responsive to input from stimuli
Explain Contractility
Stimulation of muscle fibre can lead to contraction and shortening of the muscle fibre
Explain elasticity
A contracted muscle cell can return to resting length when applied tension is removed
Explain Extensibility
The ability of a muscle fibre to be stretched beyond its resting length
What are the functions of skeletal muscle tissue
- Body movement
- Maintenance of posture
- Temperature regulation
- Storage and movement of materials
- Support
Describe the levels of organization in a skeletal muscle
Muscle
Fascicles are a bundle of muscle fibres
Muscle fibres
contain myofibrils
Myofibrils are composed of myofilaments
How are muscles attached to other body structures
At the ends of each muscle all of the connective tissue merge to form a tendon which attaches the muscle to bone, skin or another muscle
Where are muscles attached to other body structures
Most muscles extend over a joint and have attachments to
both articulating bones of that joint
What are the three types of muscles in the human body
Skeletal
Cardiac
Smooth
Describe skeletal muscle
Attached to bones or sometimes skin
Striated
Voluntary
Describe cardiac muscle
Found within heart wall
Striated
Involuntary
Describe smooth muscle
Found in the walls of hollow organs and blood vessels
No striations
Involuntary
Appearance skeletal
Long cylindrical fibre
Appearance cardiac
Short branched cell
Appearance smooth
Spindle shaped cell
Name the four organizational patterns in fascicles.
Circular
Parallel
Convergent
Pennate
Describe skeletal muscle fibre organisation
Muscle fibres are organised into fascicles within a muscle
How are muscle named, name the different criteria’s
- Muscle action
- Specific body regions
- Muscle attachments
- Orientation of muscle fibres
- Muscle shape and size
- Muscle heads/tendons of origin
What are the muscle of facial expression
Orbicularis oris
Orbicularis oculi
Describe orbicularis oris/function
compresses and purses lips
Describe Orbicularis oculi
closes eye lids; winking, blinking, squinting
What are the muscles of mastication
Temporalis, Masseter
Pterygoid muscles
Buccinator
Describe Temporalis, Masseter/function
masticatory muscles, elevates mandible
Describe Pterygoid muscles/function
side to side movement during chewing
Describe buccinator/function
helps push food onto the teeth during chewing
What are the muscles of the neck
Sternocleidomastoid
Describe Sternocleidomastoid/function
= lateral flexion and rotation; bilateral flexes neck
What are the 3 groups that the erector spinae muscles organised into
Iliocostalis
Longissimus
Spinalis
Describe Iliocostalis
Most lateral group composed of cervical, thoracic, and lumbar
parts
Describe Longissimus
Composed of capitis, cervical, and thoracic parts
Describe Spinalis
Most medial group inserting onto the spinous processes of vertebrae; composed of cervical and thoracic parts
What is the overall function of the muscle of the vertebral column
Involved in extending neck and
vertebral column, and maintaining
posture
What are the muscles of respiration
- External intercostals
- Internal intercostals
- Transverse thoracis
- Scalenes
- Diaphragm
Describe External intercostals
Elevates ribs during inhalation
Describe Internal intercostals
Depresses ribs during forced exhalation
Describe Transverse thoracis
Depresses ribs during exhalation
Describe Scalenes
elevate the ribs (1 & 2) during forced inhalation
Describe Diaphragm
The major muscle of respiration
Contraction and relaxation cause an increase and decrease in the vertical dimensions of the thoracic cavity
Describe external oblique
Most superficial lateral muscle; directed inferomedial
Describe internal oblique
Middle of three lateral muscles; directed at right angle to
external oblique
Describe transverse abdominis
Deepest of three lateral muscles; directed
horizontally
Describe rectus abdominis
Anterior muscle connecting sternum to pubic bone;
divided into four muscle segments
Describe unilateral action
lateral flexion/rotation of vertebral column
Describe bilateral action
flexes vertebral column, compresses abdominal wall;
forced exhalation
Glenohumeral joint muscles(origin on the axial skeleton
Latissimus dorsi
Pectoralis major
Describe Latissimus dorsi
extends shoulder; adduction and medial rotation of the
shoulder
Describe Pectoralis major
flexes shoulder; adduction/medial rotation at the
shoulder
Glenohumeral joint muscles(origins on the scapula)
Deltoid Teres major Triceps brachii Biceps brachii Rotator cuff muscles
Describe deltoid
- fibres in 3 directions (flexion; abduction; extension)
Describe teres major
extension, adduction and medial rotation
Describe triceps brachii
extension of the shoulder and elbow joint
Describe biceps brachii
- flexion of the shoulder and elbow joint
Describe rotator cuff muscles
- stabilise the shoulder joint
Flexors of the forearm
- Biceps brachii - primer flexor
- Brachialis
- Brachioradialis
Extensors of the forearm
Triceps brachii - prime extensor
