Week 4 - Joints and movement/Muscle Flashcards
What two functions do joints have?
Hold bones together
Facilitate movement
What are the structural classification of joints?
- Fibrous connective tissue (for strength and support)
- Cartilage (For cushioning and strength and flexibility)
- Mixture of both plus a special fluid (synovial fluid) (Synovial joint for cushioning and lubrication of joint)
Characteristics of fibrous joints
- No joint cavity
- Collagen fibres extend from matrix of one bone to another
- Amount of movement within the joint depends on the length of collagen fibre
what are the 3 different fibrous joints
- Suture (skulls bony joints)
- Syndesmosis (Ligaments)
- Gomphosis (Peg in socket, Teeth)
2 types of cartilaginous joints
symphyses (Pubic, pelvic)
synchondroses (hyaline cartilage) Bone, Cartilage, bone
Characteristics of synovial joint
- Most common
- Articulating bones are separated by a fluid-filled joint cavity
- Lubricated by synovial fluid
- Enclosed in a double layered fibrous capsule
- Reinforced by ligaments
5 Basic components of synovial joint
- Articular cartilage (hyaline)
- Synovial cavity
- Articular capsule
- outer fibrous layer
- inner synovial membrane - synovial fluid
- secreted by the synovial membrane
- plus hyaluronic acid plus phagocytes
- traps water in synovial cavity - Ligaments (“Strap-like” tissue)
Difference between tendons and ligaments
Tendons hold muscle to bone
Ligaments hold bone to bone
3 types of functional classification of joints
- Synarthroses
- Syn = together
- immovable
- Amphiarthroses
- -Amphi = both sides
- -Slightly moveable
- Diarthroses
- Dia = apart
- Freely moveable
Angular movement in bones (increase or decrease angle between two bones) terms
- Flexion/Extension
- Usually along the sagittal plane
- Flexion decreases angle
- Extension increases angle - Abduction/adduction
- Abduct = take away
- Adduct = bring closer - Circumduction/Rotation
Others
- Supination (turning outwards/supine)
- Pronation (turning inwards/prone)
- Dorsiflexion (lifting the foot up)
- Plantar flexion (pointing the toe)
4 Characteristics of muscle tissue
Excitability
Contractility
Extensibility
Elasticity
Three types of muscle tissue
- Skeletal: striated, voluntary control, get tired
- Cardiac muscle: striated, involuntary control (heart)
- Smooth muscle: non-striated, involuntary control
the 3 sarcomere protein composition
Contractile proteins
- myosin and actin
Regulatory proteins
- switch contraction on and off
- troponin and tropomyosin
Structural proteins
- provide correct alignment
- elasticity and extensibility
the 2 regulatory proteins
troponin and tropomyosin
Thick filaments characteristics
- Myosin filaments
- 2 Globular heads
- Heads face outwards
- Bind to Actin!
- ATP binding site
Composition of thin filaments
- mainly Actin
- Tropomyosin
- Troponin
Resting membrane potential Definition
Due to the selective permeability of the plasma membrane, the inside of the cell is negatively charged compared with the outside.
- -70mV inside is more negative
Nerve impulses are also known as
Action potential
Hypertrophy characteristics
(Hyper = Too much)
- Increase in diameter of muscle fibres
- Resulting from forceful, repetitive muscular activity
- increase in cell size, not cell number
Atrophy characteristics
(A = lacking, without/ trophy = nourishment)
- Wasting away of muscles
- Caused by disuse or damage to nerve supply
- can be irreversible in some cases
Cardiac muscle characteristics
- Only found in the heart
- Involuntary control
- Striations present
- Short, Branching shape
- One or two nuclei per cell
Smooth Muscle Characteristics
- Involuntary control
- one nucleus per cell
- No striations
- Spindle=shaped
- lines hollow organs and tubes
Types of smooth muscle
Unitary smooth muscle
- Most common
- In the walls or all hallow organs except heart
Multi unit smooth muscle
- Gap junctions and spontaneous depolarisations are rare
- Muscle fibres that are structurally independent
- Large airways to lungs, large arteries, arrector pili, internal eye mucles
