Week 4 Flashcards
(54 cards)
How many muscles are in the body?
650
How many joints are in the body?
187
What are the three types of muscle
Cardiac, smooth and skeletal
Describe cardiac muscle
Small cells limited by ability to repair. Involuntary muscle contractions. Single nuclei
Describe skeletal muscle
Larger cells, can be 30cm long for one cell, can be repaired however forms scar tissue. Consciously contracts. Multiple nucleus
Describe smooth muscle
Single nuclei, can be repaired, involuntary contracts
What are the functions of muscle tissue
Produces body movement
Stabilises body positions
Regulates organ volumes - bands of smooth muscles called sphincters
Movement of substances within the body - blood, lymph, urine, food, fluid, sperm
Produces heat
Properties of muscle tissue
Excitability - respond to chemicals from nerve cells
Conductibility - propagate electrical signals over membrane
Contractability - short and generate force
Extensibility - to be stretched without damaging tissue
Elasticity - ability to return to original shape
What does muscle tissue look like
Striated with light and dark bands
Functions of skeletal muscle
Produces skeletal movement
Maintain body position
Support soft and hard tissues
Guard body openings
Maintain body temperature
Stores nutrient reserves
Proprioception
What are the three connective tissues found in skeletal muscle structures?
Epimysium - outerlayer - dense irregular CT - separates muscle from surrounding tissue, connect to deep fascia.
Permysium - middle layer - surrounds each muscle fibre cell. Contains blood vessels and nerve supply 50/50 collagen and elexistin
Endomysium - inner layer - surrounds individual muscle cells. Contains capillary and nerve fibres contracting muscle. Contains satellite cells
What makes a tendon or aponeurosis
Endomysium, permysium and epimysium come together at the end of muscles to form connective tissue attachments to bone matrix
Which connective tissues are nerves found in?
Perimysium and Endomysium
Messages reach the muscle via…
Peripheral nerve
A collection of muscle cells are supplied by…
A motor neuron
What makes a motor unit
One motor nerve and the muscle fibre it supplies
What supplies each muscle cell with a nerve signal
Terminal banco of a motor neurone
How many capillaries are a muscle cell in contact with
1 or 2
Where are nerve fibres and capillaries found?
Endomysium between individual cells
What is the role of the vascular system within the muscles?
To supply large amounts of O2
Supply nutrients
Carry away waste products; lactic acid, water and CO2
How are skeletal muscle cells developed?
Fusion of mesodermal cells called fibroblasts. Myoblasts flatten and fuse to become and immature muscle fibre. Then become mature
What shape are muscle fibres?
Long and cylindrical
What is the sarcolemma
The cell membrane, surrounds the sarcoplasma.
What is the sarcoplasma filled with?
Tiny threads called myofibrils and myoglobin
