Introduction Flashcards
Define myology
Study of muscles
What are the results of muscle contractions amd relaxations
Body movements
What are the results of muscle contractions amd relaxations
Body movements
Effects of nerve impulse stimulation
Contracts when there is a stimulation and relax after the nerve impulse is removed
Effects of nerve impulse stimulation
Contracts when there is a stimulation and relax after the nerve impulse is removed
What are the functions of muscles
- They produce movement
- Maintain posture and body position
- Support soft tissue
- Protect entrances and exits
- Maintains body temperature
What are the functions of muscles
- They produce movement
- Maintain posture and body position
- Support soft tissue
- Protect entrances and exits
- Maintains body temperature
4 Common characteristics of all muscles
- Irritability
- Contractility
- Extensibility
- Elasticity
4 Common characteristics of all muscles
- Irritability
- Contractility
- Extensibility
- Elasticity
What doest the word irritability mean in relation to muscles
Means sensitive to stimuli from nerve impulses
What does the word contractility mean in relation to muscle
Means responding to stimuli by contacting
What does the word extensibility mean in relation to muscles
Being able to stretch beyond their mormal size
Types of muscle tissue
Skeletal muscle
Smooth muscle
Cardiac muscle
What are fascicles
Are muscle fibers or cells bundled together
What is the appearance of skeletal muscle
They are striped, roughly cylindrical in shape muscle fibers
What are skeletal muscles
They are involuntary muscles
What is the role of connective tissues in skeletal muscles
Connective tissue are used to attach one fiber to another and also attach one fascicle to another
What is a epimysium
Is a membrane that covers the whole muscle tissue
What is the epimysium connected to
To a tendon which comnects the muscle to the bone
What is a myofibrin
Is a thread like structure embeded in the muscle fiber
What comprises the myofibril
A protein actin and myosin which is responsible for muscle contraction
What is sarcolema
Is a cell membrane surrounding each muscle fiber
What is endomysium
a fine sheath of connective tissue
surrounding individual fiber of muscles.
what is perimysium
connective tissue which binds groups of muscle fibers together into bundles.
define epimysium
means a membrane that covers the whole muscle
skeletal muscles are classified basing on the patten of fascicles. mention the patten
a. Parallel muscles
b. Convergent muscles
c. Circular (sphincteral) muscles
d. Pennate muscles
define the arrangement of parallel muscles
*Fascicles are parallel to the long axis of the muscle
what happens to parallel muscles during contractions
During contractions it shortens and becomes large in diameter.
mention 2 examples of parallel muscles
- Sartorius muscles
- Rectus abdominis muscles.
What is the most common skeletal muscle in the body
parallel muscle
What is the defining characteristic of convergent muscles?
Convergent muscles have muscle fascicles that extend over a large area but come together at a common attachment point. This arrangement allows the muscle fibers to spread out like a broad triangle, with a tendon at the apex.
Provide examples of convergent muscles
- Deltoid muscle
- pectoralis muscle
What is the characteristic arrangement of muscle fascicles in circular (sphincteral) muscles
Circular muscles have concentrically arranged fascicles around an opening. These fascicles encircle the opening like a ring.
What happens to the diameter of the opening during muscle contraction in circular muscles?
During muscle contraction, the diameter of the opening becomes smaller. This constriction helps regulate the flow of substances through the opening.
Where are circular muscles commonly found in the body, and what role do they play
Circular muscles surround body openings and act as valves. They control the passage of materials in structures like the digestive tract (e.g., the pyloric sphincter) and the urinary system (e.g., the internal urethral sphincter).
Provide examples of circular (sphincteral) muscles.
Orbicularis Oris: This muscle encircles the mouth and controls lip movements.
Orbicularis Oculi: Found around the eye, it helps close the eyelid
What is the defining characteristic of pennate muscles?
Pennate muscles have muscle fascicles that form a common angle with the tendon. This arrangement allows for more muscle fibers within the muscle.
How do pennate muscles differ from parallel muscles in terms of muscle fiber arrangement?
Pennate muscles contain more muscle fibers (and consequently more myofibrils) than parallel muscles. The oblique arrangement of fibers in pennate muscles increases their cross-sectional area.
Which types of pennate muscles exist, and what are their characteristics?
- Unipennate: Fibers run obliquely from a tendon on one side only (e.g., biceps femoris, extensor digitorum longus, tibialis posterior).
- Bipennate: Fibers run obliquely on both sides from a central tendon (e.g., rectus femoris, flexor hallucis longus).
- Multipennate: Have several tendons with fibers running diagonally between them (e.g., deltoid).
True or False: Any pennate muscle produces greater tension than a parallel muscle.
True. Pennate muscles indeed generate more tension due to their increased muscle fiber density
Give an example of a multipennate muscle
The deltoid muscle is an example of a multipennate muscle
What muscle type has shorter fibers arranged obliquely to their tendons, similar to a feather
Unipennate muscles exhibit this arrangement
What is the primary characteristic of functional groups of muscles?
Functional groups of muscles contract together rather than independently. They work collaboratively to achieve specific movements.
Define “Synergist” in the context of muscle function
Synergists are muscles that contract together to achieve a particular movement. They assist the prime mover (agonist) by promoting the same movement or by stabilizing undesirable/unnecessary movements during contraction.
Give an example of synergistic muscles related to elbow joint movement
The brachioradialis and brachialis assist the biceps brachii in creating movement at the elbow joint. When the biceps contract, these synergists help achieve elbow flexion.
What is the primary function of fixator muscles?
Fixator muscles mainly function as joint stabilizers. They work to maintain the stability and balance of a joint during movement
How do fixators contribute to posture
Fixators help maintain upright posture. By stabilizing joints, they prevent unnecessary movement and keep the body in a balanced position.
Give an example of fixator muscles related to the shoulder joint
The rotator cuff muscles serve as fixators for the shoulder joint. They secure the head of the humerus within the glenoid cavity, providing stability during arm movements.
What is the primary role of agonist muscles?
Agonist muscles provide the major force for producing movement. They are responsible for initiating and controlling specific movements.
What other term is commonly used to refer to agonist muscles?
Agonist muscles are also known as “prime movers.”
Give an example of an agonist muscle and its associated movement
The biceps muscle serves as an agonist during elbow flexion. When you perform a bicep curl, the biceps brachii contract to lift the weight, causing flexion at the elbow joint.
What is the primary role of antagonist muscles?
Antagonist muscles oppose the action of the agonist (prime mover) or reverse a specific movement. They work in opposition to the agonist.
Give an example of an antagonist muscle pair related to elbow movement.
During elbow flexion (such as when you bend your arm), the biceps brachii muscle acts as the agonist (prime mover), while the triceps brachii serves as the antagonist. The biceps contract to flex the elbow, and the triceps relax to allow this movement.
True or False: Antagonist muscles always work against the agonist
True. Antagonists oppose the specific movement initiated by the agonist.
What muscle performs the antagonist movement when you straighten your arm?
The triceps muscle acts as the antagonist when you straighten your arm (elbow extension).
Which two muscles are involved in hip flexion
The quadriceps (agonist) and hamstrings (antagonist) work together during hip flexion
Skeletal muscles are named basing on which factors
Location
Points of attachment
Orientation of fibers
Size
Function
Number of heads
shape
which muscles are named after their shape
Trapezius (like a trapezoid)- Deltoid (triangle)- Pyramidal (pyramid)
which muscles are named after their location
Coccygeus (coccyx)- Femoris (femur)
27- Lumborum (lumbar region)
