Muscular System Overview

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Questions and Answers

What are the three main types of muscle found in the muscular system?

Striated, Cardiac, and Voluntary

Skeletal, Cardiac, and Involuntary

Skeletal, Smooth, and Cardiac (correct)

Smooth, Cardiac, and Striated

Which of the following is NOT a function of the muscular system?

Movement

Maintenance of posture

Digestion of food (correct)

Protection of bones

What is the role of the prime mover in a muscular movement?

To act opposite to the action of another muscle

To assist in movement alongside other muscles

To initiate and perform the main movement (correct)

To stabilize the joint during movement

How do antagonistic muscle pairs function?

One contracts while the other relaxes Signup and view all the answers

Which type of muscle is characterized as involuntary and striated?

Cardiac muscle Signup and view all the answers

What type of muscle can be described as spindle-shaped and contracts slowly?

Smooth muscle Signup and view all the answers

What is the primary way in which the muscular system contributes to body temperature regulation?

By producing heat through muscle contractions Signup and view all the answers

Which of these statements about voluntary muscles is correct?

They can be moved at will. Signup and view all the answers

Which muscle type is found only in the heart and does not fatigue?

Cardiac muscle Signup and view all the answers

What is the primary function of the urinary bladder?

Controls urination Signup and view all the answers

Which type of muscle fiber is characterized as white muscle and fatigues quickly?

Type IIx Signup and view all the answers

Which muscle is responsible for the abduction of the shoulder?

Deltoid Signup and view all the answers

Which structure secretes synovial fluid and is found between tendons and bones?

Bursa Signup and view all the answers

What type of muscle fibers are categorized as red muscle and resist fatigue well?

Type I Signup and view all the answers

Which muscle primarily assists in flexing the elbow?

Biceps Signup and view all the answers

What is the membrane surrounding a muscle cell called?

Sarcolemma Signup and view all the answers

What is the primary movement associated with the tibialis anterior muscle?

Dorsiflexion of the ankle Signup and view all the answers

Which muscle group is responsible for hip extension?

Gluteus maximus Signup and view all the answers

What type of contraction occurs when a muscle lengthens while under tension?

Eccentric contraction Signup and view all the answers

Which of the following describes the role of the antagonist muscle?

It relaxes while the agonist muscle contracts. Signup and view all the answers

Which muscle is primarily responsible for extending the elbow?

Triceps Signup and view all the answers

Which classification of muscles is responsible for moving a limb away from the midline of the body?

Abductor Signup and view all the answers

What is an example of a muscle named based on its size?

Maximus Signup and view all the answers

What muscle group is primarily responsible for knee flexion?

Hamstrings Signup and view all the answers

Study Notes

The Muscular System

The muscular system is an organ system that consists of skeletal, smooth, and cardiac muscle.
Its primary functions include:
- Movement
- Posture maintenance
- Heat production
- Protection of bones and internal organs

Muscle Types

Skeletal muscle is voluntary and attached to the skeleton.
- Fibers are long, cylindrical, and striated.
- Multiple nuclei
- Responsible for movement of bones at joints.
Smooth muscle is involuntary and found in the internal organs and blood vessels.
- Fibers are thin and spindle-shaped.
- Single nuclei
- Contracts slowly and fatigues slowly.
Cardiac muscle is involuntary and found only in the heart.
- Cells are branched and appear fused.
- Has striations
- Each cell has a central nucleus.
- Responsible for pumping blood throughout the body.
- Never fatigues.

Muscle Actions and Interactions

Synergists are muscles that work together to perform a movement.
- Prime movers (agonists) are the main muscles responsible for a movement.
- Antagonists are muscle groups that work in pairs to produce opposite actions.
  - One contracts while the other relaxes.
Levators raise a body part.
Depressors lower a body part.
Rotators rotate a bone along its axis.
Sphincters constrict an opening.

Muscle Contractions

Isotonic contractions involve muscle shortening (concentric) or lengthening (eccentric).
Isometric contractions involve muscle tension without a change in length.

Muscle Naming Conventions

Muscle names often reflect their:
- Size: vastus (huge), maximus (large), longus (long), minimus (small), brevis (short)
- Shape: deltoid (triangular), rhomboid (rhombus-shaped), latissimus (wide), teres (round), trapezius (trapezoid-shaped)
- Fiber direction: rectus (straight), transverse (across), oblique (diagonally), orbicularis (circular)
- Location: pectoralis (chest), gluteus (buttock), brachii (arm), supra- (above), infra- (below), sub- (under), lateralis (lateral)
- Number of origins: biceps (two heads), triceps (three heads), quadriceps (four heads)

Key Muscles and Their Functions

Deltoid: Abducts the shoulder (moves arm away from the body).
Pectoralis major: Adducts the shoulder (moves arm towards the body) and performs shoulder horizontal flexion (moves arm forward).
Biceps: Flexes the elbow (bends the arm).
External obliques: Rotate the trunk (twisting the body).
Hip flexors: Flex the hip (moves knee up to the chest).
Quadriceps: Extend the knee (straightens the leg).
Tibialis anterior: Dorsiflexes the ankle (brings toes up towards the shin).
Triceps: Extends the elbow (straightens the arm).
Latissimus dorsi: Adducts the shoulder (moves arm towards the body).
Gluteus maximus: Extends the hip (moves leg backwards).
Hamstrings: Flex the knee (bends the leg).
Gastrocnemius: Plantar flexes the ankle (points toes downwards).

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Description

This quiz covers the muscular system, including its types and functions. Explore the differences between skeletal, smooth, and cardiac muscles, their roles in movement, posture, and heat production. Test your knowledge on muscle actions and interactions.