NEET Revision Notes
Biology
Locomotion and Movement
Introduction
● Movement is a feature shared by all living organisms. It constitutes the
various key aspects of living organisms, ranging from protoplasmic motion
in a cell or unicellular organisms to organ movement in complex
organisms.
● Locomotion refers to the movement that results in a location change.
Types of Movements:
● There seem to be three types of movement in a cell and organ. They are as
follows:
1. Amoeboid movement: Similar to pseudopodia in amoeba, ameboid
movement can be seen in macrophages, leukocytes, and even
cytoskeletal microfilaments.
2. Ciliary and flagellar movement: Ciliary motion in the tracheal
epithelial lining, reproductive tract, and so on. Flagellar movement
is seen in sperm.
3. Muscular movement: Muscles account for the majority of
movement in a complex organism. Breathing, heart function,
digestion, appendage movement, and locomotion are all carried out
by various muscles of our body. The synchronised movement of the
skeletal, neural, and muscular systems is referred to as locomotion.
Muscle
● Muscles develop from the germinal layer of the mesoderm.
● Muscular tissues have distinct characteristics including contraction,
excitation, extension, elasticity, and so on.
● We are all aware that there are three types of muscles:
1. Cardiac muscles are striated and involuntary muscles found in the
heart.
2. Visceral muscles are nonstriated and smooth. They are
involuntary too and support different internal organs as well as
participate in functions including digestion and reproduction.
Class XII Biology www.vedantu.com 1
, 3. Skeletal muscles are striated and voluntary muscles that control
locomotion and appendage movement.
Image: Types of Muscles
Muscle Fibre and Sarcomere Anatomy
● Skeletal muscles are present in the animal's body most abundant.
● They are composed of bundles of muscle fibres surrounded by connective
tissue.
Image: Structure of a skeletal muscle fibre
● Fascicles (Muscle Bundles): A muscle, such as a biceps, is made up of
numerous muscle bundles (fascicles) that are held together by fascia, a
connective tissue layer. Several muscle fibres are found in each fascicle.
● Muscle Fibres: Muscle fibres are long cells. They are grouped into
fascicles. Muscle fibres have the following characteristics:
➢ Skeletal muscle fibres are all long, cylindrical, and striated.
➢ It is syncytium, which means it has many nuclei.
➢ The plasma membrane of the muscle fibre is known as the
sarcolemma.
➢ Sarcoplasm is the muscle fibre's cytoplasm.
➢ The sarcoplasmic reticulum is the muscle fibre's endoplasmic
reticulum. It is the Ca2+ storage facility.
Class XII Biology www.vedantu.com 2
Biology
Locomotion and Movement
Introduction
● Movement is a feature shared by all living organisms. It constitutes the
various key aspects of living organisms, ranging from protoplasmic motion
in a cell or unicellular organisms to organ movement in complex
organisms.
● Locomotion refers to the movement that results in a location change.
Types of Movements:
● There seem to be three types of movement in a cell and organ. They are as
follows:
1. Amoeboid movement: Similar to pseudopodia in amoeba, ameboid
movement can be seen in macrophages, leukocytes, and even
cytoskeletal microfilaments.
2. Ciliary and flagellar movement: Ciliary motion in the tracheal
epithelial lining, reproductive tract, and so on. Flagellar movement
is seen in sperm.
3. Muscular movement: Muscles account for the majority of
movement in a complex organism. Breathing, heart function,
digestion, appendage movement, and locomotion are all carried out
by various muscles of our body. The synchronised movement of the
skeletal, neural, and muscular systems is referred to as locomotion.
Muscle
● Muscles develop from the germinal layer of the mesoderm.
● Muscular tissues have distinct characteristics including contraction,
excitation, extension, elasticity, and so on.
● We are all aware that there are three types of muscles:
1. Cardiac muscles are striated and involuntary muscles found in the
heart.
2. Visceral muscles are nonstriated and smooth. They are
involuntary too and support different internal organs as well as
participate in functions including digestion and reproduction.
Class XII Biology www.vedantu.com 1
, 3. Skeletal muscles are striated and voluntary muscles that control
locomotion and appendage movement.
Image: Types of Muscles
Muscle Fibre and Sarcomere Anatomy
● Skeletal muscles are present in the animal's body most abundant.
● They are composed of bundles of muscle fibres surrounded by connective
tissue.
Image: Structure of a skeletal muscle fibre
● Fascicles (Muscle Bundles): A muscle, such as a biceps, is made up of
numerous muscle bundles (fascicles) that are held together by fascia, a
connective tissue layer. Several muscle fibres are found in each fascicle.
● Muscle Fibres: Muscle fibres are long cells. They are grouped into
fascicles. Muscle fibres have the following characteristics:
➢ Skeletal muscle fibres are all long, cylindrical, and striated.
➢ It is syncytium, which means it has many nuclei.
➢ The plasma membrane of the muscle fibre is known as the
sarcolemma.
➢ Sarcoplasm is the muscle fibre's cytoplasm.
➢ The sarcoplasmic reticulum is the muscle fibre's endoplasmic
reticulum. It is the Ca2+ storage facility.
Class XII Biology www.vedantu.com 2
