What Is the Animals Nervous System Definition Structure Types and Functions
Nervous system of an animal is a complex structure, it mainly receives and detects signals from the surroundings and after detecting that signal, sends it to the brain. Nervous system structure can be detected by studying the body plan of the organism body. Example: The organism which are divided on the basis of head and tail, then in them they have a web like nerve cell which is spreaded throughout the body. Organisms who have a well defined head, then their nervous system is divided into three parts, they are: the Central Nervous System, Peripheral Nervous System, and Autonomous Nervous System.
Classification of Nervous System:
1. Central Nervous System– It consists of the brain and spinal cord. It’s location is in the head and continues along the back.
Brain: It is considered as the most important, largest and central part of the human nervous system. It controls all the functions of the nervous system, which help in getting messages and giving response to the human body. Human brain is covered by the skull, which provides protection from the frontal, lateral and dorsal side. The human brain is further divided into three major parts:
Forebrain: It is anterior most part of the brain consists of Cerebrum, Hypothalamus and Thalamus.
Midbrain: It is the smaller and central part of the human brain.
Hindbrain: It is the central region of the brain which is made up of Cerebellum, Medulla and Pons.
Spinal Cord: It is a cylindrical bunch of nerves, which is enclosed by spine. This spine connects all parts of the human body to the brain. It starts in continuation with the medulla and extends towards downward direction. It is covered by a bony cage called the vertebral column and surrounded by a membranous structure known as meninges.
2. Peripheral Nervous System– It consists of all the nerves continuing from the central nervous system to the entire body. It is the lateral most part of the human nervous system which helps in connecting different parts of the body with CNS.
Peripheral nervous system has two types of nerve fibers:
A. Afferent nerve fibers – These nerve fibers are responsible for transmission of messages from tissues and organs to the central nervous system.
B. Different nerve-fibers – These nerve fibers are responsible for sending messages from CNS to the corresponding peripheral organ.
C. Autonomous Nervous System– It is made up of both sympathetic and parasympathetic nerves.
Classification of Peripheral Nervous System:
Somatic Neural System (SNS): This neural system controls all the voluntary actions in the body by transmitting impulses from CNS to skeletal muscle cells.
Autonomic neural system (ANS): The autonomic neural system controls all the involuntary actions of the body like regulation of physiological functions (digestion, respiration, salivation, etc.).
3. Autonomous Nervous System– It is made up of both sympathetic and parasympathetic nerves.
Parts of Human Brain:
The human brain is made of the following parts and perform the given functions:
A. Cerebral Cortex – It controls the Voluntary movement, reasoning, language, perception.
B. Cerebellum – It helps in maintaining balance, movement and body posture. It further gets splitted into two hemispheres.
C. Hypothalamus – This part of the brain is responsible for the regulation of the temperature of the body, hunger centre, emotions, regulation of the circadian rhythms etc.
D. Medulla oblongata: It is also known as brain stem. It regulates functions like heart rate, breathing and blood pressure
E. Thalamus – It regulates the motor and sensory information and obtains the sensory information which further carries forward the information to the cerebral cortex.
F. Limbic system – It helps in maintaining the response to different emotions.
G. Basal Ganglia – It maintains the movements and balance and also has the caudate nucleus, globus pallidus, putamen, substantia nigra and subthalamic nucleus.
H. Midbrain – It controls various functions like hearing, vision, body movement, eye movement.
Parts of Nervous System:
Neuron:
Neurons are known as structural and functional units of the nervous system. It is of irregular shape and has the capability to conduct electrical signals. Neurons are further divided into different parts, which are discussed below:
A. Dendrite: It is the shortest fiber in the cell and extends out from the cell body of a neuron.
B. Axon: It is considered as the longest thread in the human body of a neuron and also covered by insulating and protective covering of sheath known as myelin sheath.
C. Cell body: It is made up of cytoplasm and nucleus.
D. Synapse: Gap present between adjacent pairs of neurons, through which nerve impulses pass is known as synapse.
E. Dendrites: They are present on either side of the neuron. They look like branch projections, which connect with the adjacent neuron.
Types of Nerves:
Combination of several axons are bundled together to form a nerve. Further nerves are divided into three types they are:
A. Sensory nerve: When nerve impulse travels through the receptor to the brain or spinal cord are called sensory nerve fibers. Example. nerves in the eyes, nerves, and ears.
B. Motor nerve: When the transmission impulse is from the brain or spinal cord to the gland or muscle, it is called a motor neuron.
C. Mixed neuron: A mixed nerve consists of both the sensory and the motor nerves. Example of a mixed neuron is spinal nerves.
FAQs on Animals Nervous System Structure and Function Explained
1. What is the nervous system in animals?
The nervous system in animals is a specialized network of cells and tissues that controls and coordinates body activities by transmitting electrical and chemical signals. It allows animals to sense their environment, process information, and respond appropriately.
- It is made up of neurons and supporting cells called neuroglia.
- It detects stimuli such as light, sound, touch, and temperature.
- It controls actions like movement, feeding, and behavior.
- In higher animals, it includes the brain, spinal cord, and nerves.
2. What are the main parts of the animal nervous system?
The main parts of the animal nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS). These two divisions work together to control body functions.
- CNS: Includes the brain and spinal cord; processes and integrates information.
- PNS: Consists of nerves outside the CNS; carries messages to and from the CNS.
- The PNS further includes the somatic nervous system and autonomic nervous system.
3. How does the nervous system work in animals?
The nervous system works by transmitting nerve impulses through neurons to coordinate responses to stimuli. These impulses are electrical signals that travel along nerve cells and chemical signals at synapses.
- Step 1: Receptors detect a stimulus (e.g., heat or light).
- Step 2: Sensory neurons carry impulses to the CNS.
- Step 3: The CNS processes the information.
- Step 4: Motor neurons transmit commands to effectors (muscles or glands).
4. What is a neuron and what is its function?
A neuron is the structural and functional unit of the nervous system that transmits nerve impulses. It is specialized to receive, process, and send information throughout the body.
- Dendrites: Receive signals from other cells.
- Cell body: Processes the information.
- Axon: Carries impulses away from the cell body.
- Neurons communicate at junctions called synapses.
5. What is the difference between the central and peripheral nervous system?
The difference between the central nervous system and the peripheral nervous system is that the CNS processes information while the PNS transmits signals between the CNS and the rest of the body. Both are essential for coordination and control.
- CNS: Brain and spinal cord; integration and decision-making center.
- PNS: Cranial and spinal nerves; communication network.
- The PNS connects sensory receptors and effectors to the CNS.
6. What are the types of neurons in animals?
The three main types of neurons in animals are sensory neurons, motor neurons, and interneurons. Each type plays a specific role in signal transmission.
- Sensory neurons: Carry impulses from receptors to the CNS.
- Motor neurons: Transmit impulses from the CNS to muscles or glands.
- Interneurons: Connect sensory and motor neurons within the CNS.
7. What is a reflex action in animals?
A reflex action is a rapid, automatic response to a stimulus that occurs without conscious control. It helps protect the body from harm and is mediated through a reflex arc.
- Stimulus is detected by receptors.
- Impulse travels via a sensory neuron to the spinal cord.
- An interneuron processes the signal.
- A motor neuron activates an effector (e.g., muscle withdrawal).
8. How is the nervous system different in vertebrates and invertebrates?
The nervous system in vertebrates is highly centralized with a well-developed brain and spinal cord, while invertebrates often have simpler or differently organized systems. The level of complexity varies among animal groups.
- Vertebrates: Distinct brain regions and dorsal spinal cord.
- Invertebrates: May have nerve nets (e.g., cnidarians) or ventral nerve cords (e.g., annelids, arthropods).
- Cephalopods show advanced nervous systems among invertebrates.
9. What is the function of the autonomic nervous system in animals?
The autonomic nervous system (ANS) controls involuntary body functions such as heartbeat, digestion, and breathing. It regulates internal organs without conscious effort.
- Sympathetic division: Prepares the body for “fight or flight.”
- Parasympathetic division: Promotes “rest and digest” activities.
- Maintains homeostasis in the body.
10. Why is the nervous system important for survival in animals?
The nervous system is essential for animal survival because it enables rapid response to environmental changes and coordinates vital body functions. Without it, animals cannot sense danger, find food, or maintain internal balance.
- Detects and responds to external stimuli.
- Coordinates movement and behavior.
- Regulates vital processes like respiration and circulation.
- Supports learning, memory, and adaptation.
