Properties of Muscles Flashcards
Properties of Muscle: Electrical Excitability. (3 points)
Muscles can change due to external stimuli:
- electrical
- hormonal
- ion changes allowing for an action potential leading to contractions
Properties of Muscle: Contractility.
Action potentials allowing for sarcomere’s to contract, muscles to move, thus moving bone.
Properties of Muscle: Extensibility.
The ability to stretch.
Muscular tissue type determines how extensible it is.
Define Spasticity.
Lack of muscular extensibility.
Properties of Muscle: Elasticity.
The ability for muscle fibres to return to their original state without damage.
Plays an important role in extensibility of muscle.
Properties of Muscle Fibres. (4 points)
Electrical Excitability, Contractility, Extensibility, Elasticity.
Functions of Muscle: Movement
Muscular contraction pulls bone, allowing for the movement of joints and thus limbs.
Functions of Muscle: Stabilising body positions.
Many muscles continually making small, not forceful contractions to ensure body positions are kept (e.g. posture).
Functions of Muscle: Storage & Movement of substances within the body.
E.g. Calcium & blood. During respiration, circulation, and muscle contraction.
Functions of Muscle: Heat Generation.
Heat is generated & released in muscular contractions to maintain core body temperature within homeostasis.
E.g. shivering to raise core body temperature.
Functions of Muscle. (4 points)
Movement, Stabilisation of body positions,, Heat generation and Storage & Movement of substances within the body.
Types of Muscular Tissue. (3 points)
Skeletal, Cardiac & Smooth muscle.
Define “Striated” Muscle Tissue.
Organisation of myosin & actin, forming well-organised sarcomeres.
“Marked with long, thin, parallel streaks.”
Describe properties of Skeletal Muscle. (3 points)
Striated.
Mostly voluntarily controlled muscle fibres - conscious contraction/relaxation,
nerves allow the muscle to send/receive electrical signals for an action potential to ensue, causing muscular movement.
Some involuntary muscular involvement.
Describe properties of Cardiac muscle. (4 points)
Striated.
Solely located in heart/cardiac walls.
Involuntarily controlled muscular involvements.
Contains it’s own pacemaker (the Sinoatrial Node) which causes muscular movement outside the Central Nervous System.
Describe properties of Smooth Muscle. (4 points)
Associated with the Gastrointestinal System & blood vessels.
Lacks striation that skeletal & cardiac muscle has. (also lacking the organisation of myosin & actin filaments that create sarcomeres)
Myosin & Actin filaments are present but not strictly organised.
Greater extensibility than skeletal & cardiac muscle.
Aponeurosis
An amalgamation of tendons from several different types of muscle spread over a wide area.
Important in the anterior portion of the abdomen - no bones, so thicker, more protective portion of tendon is required.
Dissections: Muscle belly
Dark/er brown
Dissections: Tendons
Light/er, more white.
Shiny/glistening.
Dissections: Neurovascular bundle
Wrapped in Connective Tissue.
1 nerve - axons are spread to different muscle cells.
1 artery.
1-2 veins.
Describe the concept “Vena Comitans”.
2 veins surrounding the sides of an artery.
Properties of: Muscle Belly.
Skeletal muscle cells are surrounded by differing levels of Connective Tissue (CT).
The CT comes together to form tendons.
Belly shape and strength is determined by it’s function (either thick & robust or wide).
Properties of: Tendons.
Muscle to bone attachment.
Connective Tissue continues from muscle belly through to attach to bone.
Shape and strength are determined by tendon function - either rope-like (biceps brachii) or flat & expansive (rectus sheath of interior abdomen.
Name the 2 Muscle Attachment Sites.
Origin (Proximal attachment) & Insertion (Distal attachment).
