Animals Nervous System
May 15, 2023, 16:45 IST
The goal of the article is to briefly describe the animal nervous system. Continue reading to understand more about the nervous system's classification, parts, and functions.
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Introduction
The nervous system of animals has a complex structure that organizes their behavior and mediates sensory signals between different parts of the body. Mainly it receives and interprets the sensory signals from the surroundings and then sends out direct messages to the brain. The complexity depends on the lifestyle of the organism and body plans. For example -
- Animals without a defined head or tail have web-like arrangements of nerve cells all over their bodies.
- Animals who have well-defined heads or tails possess three different parts of the nervous system
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
- Autonomous Nervous System (ANS)
Also, check - Animal Tissue Type
Classification of the Nervous System
- Central Nervous System (CNS)
CNS contains the brain and spinal cord. Its position is in the head and pursues along the back.
A- Brain- It is described as an important, largest, and central part of the human neurological system. It helps in receiving messages and transmitting responses to the nerves of the human body. The brain is located in the skull which has cerebrospinal fluid that helps to protect the brain from any mechanical shocks. It is further divided into three types:
- Forebrain- It is the most anterior part of the brain that has the cerebrum, hypothalamus, and thalamus. The process of thinking, receiving impulses from the receptor, and analyzing different signals like hearing and smelling takes place here.
- Midbrain- It is a central part of the brain. It analyzes the voluntary (under human control like running and pushing) and involuntary functions (not under human control like breathing and blinking) performed by the human body.
- Hindbrain- It is made up of the cerebellum, medulla, and pons. It helps in controlling blood pressure, breathing, salivation, etc.
B- Spinal Cord- A long bundle of nerves and cells called the spinal cord runs from the lower part of the brain to the lower back. Between the brain and the rest of the body, it carries signals.
- Peripheral Nervous System (PNS)
It is the most lateral part of the nervous system that helps in binding different parts of the body with CNS. All the nerves continue from the CNS to the all over body. It has two types of nerve fibers:
- Afferent Nerve Fiber- This nerve fiber transfers the messages from tissue to organs to the central nervous system.
- Efferent Nerve Fiber- These fibers send messages from CNS to peripheral organs.
- Autonomous Nervous System (ANS)
It includes involuntary functions that are not under human control like heartbeat, blinking, etc. It consists of two types of nerves- sympathetic and parasympathetic.
- Sympathetic Nervous System- This is responsible for the fight or flight response of the body. It increases the heart rate to move blood via the blood vessels. It automatically stimulates the body when any action is required.
- Parasympathetic Nervous System- It stimulates the secretion of digestive enzymes or saliva. It is connected with the relaxed condition for eg. slowing of the heart rate and contraction of pupils.
Parts and Functions of the Nervous System
A. Human Brain
The human brain has a different part that performs the following functions-
- Cerebral Cortex – Its main functions include perception, thought, language, and voluntary movement.
- Cerebellum – Its function involves maintaining movement, body posture, and balancing.
- Hypothalamus – It is mainly responsible for the regulation of circadian rhythms and the temperature of the body.
- Medulla oblongata or Brain stem – It is responsible for controlling heart rate, blood pressure, and breathing. It includes pons, medulla, tectum, tegmentum, and reticular formation.
- Thalamus – It helps in the regulation or integration of motor and sensory information which forwards the message to the cerebral cortex that further transmits to other areas of the spinal cord and the brain.
- Limbic system – It includes the hippocampus (vital for memory and learning),the amygdala, the thalamus, and the hippocampus. It also maintains the response to emotions.
- Midbrain – It helps in controlling various functions like hearing, vision, and movement of the body and eye. It includes a red nucleus and inferior and superior colliculi.
B. Cerebrospinal Nervous System
It includes 12 different pairs of cranial nerves that are linked to the brain having the following functions.
- Optic – It is responsible for sight.
- Oculomotor – It includes eyeball, pupils, and lens movement.
- Olfactory – It is responsible for the smell.
- Trochlear – It includes motioning of the eye muscles (superior oblique).
- Trigeminal – It supplies nerves for eyes, jaws, and cheeks and governs chewing.
- Abducens – It is responsible for outward gaze, and movement of the lateral rectus muscles in humans.
- Facial –It includes the movement of the facial muscles, regulates salivary glands, and tastes sensation from the anterior of the tongue.
- Glossopharyngeal – It maintains the sensation of taste.
- Acoustic – It maintains balance and hearing.
- Vagus – It supplies nerves for the organs in the abdomen and the chest.
- Spinal Accessory – It includes shoulder and head movement
- Hypoglossal – It maintains muscles of the tongue.
C. Parts of Nervous System
Neurons:
Neurons are defined as structural and functional units of the nervous system. Its shape is irregular and capable to conduct electrical signals. They are further divided into different parts as discussed below:
A. Axon: It has a long cylindrical structure that conducts nerve impulses away from the cell body. An axon is covered with a thin layer of insulated electrical wire known as a myelin sheath. Myelinated neurons are found in the PNS and non-myelinated neurons are found in the CNS (brain and spinal cord).
B. Cell body: It consists of a nucleus, mitochondria, endoplasmic reticulum, and ribosomes. Neuron does not survive if the cell body dies.
- Synapse: It is a gap present between the adjacent pairs via which nerve impulses pass.
- Dendrites: They are like small branch projections which is used to connect with the adjacent neuron.
Also, check - Animal Kingdom Basic Classification
Animals-Nervous FAQs
Q1. What are the classifications of the animal nervous system?
Ans.
- Central Nervous System (CNS)- CNS contains the brain and neurons/ spinal cord. Its position is in the head and pursues along the back.
- Peripheral Nervous System (PNS)- It is the most lateral part of the nervous system that helps in binding different parts of the body with CNS
- Autonomous Nervous System (ANS)- It includes involuntary functions that are not under human control like a heartbeat, blinking, etc.
Q2. What is the difference between sympathetic and parasympathetic?
Ans.
- Sympathetic Nervous System- This is responsible for the fight or flight response of the body. It increases the heart rate to move blood via the blood vessels. It automatically gets stimulates the body when any action is required.
- Parasympathetic Nervous System- It stimulates the secretion of digestive enzymes or saliva. It is connected with the relaxed condition for eg. slowing of the heart rate and contraction of pupils.
Q3. What is the function of optic and olfactory?
Ans.
- Optic – It is responsible for sight.
- Olfactory – It is responsible for the smell.
Q4. Name the different types of the human brain.
Ans. It is divided into three types:
- Forebrain- It is the most anterior part of the brain that has the cerebrum, hypothalamus, and thalamus. The process of thinking, receiving impulses from the receptor, and analyzing different signals like hearing and smelling takes place here.
- Midbrain- It is a central part of the brain. It analyzes the voluntary (under human control like running and pushing) and involuntary functions (not under human control like breathing and blinking) perform by the human body.
- Hindbrain- It is made up of the cerebellum, medulla, and pons. It helps in controlling blood pressure, breathing, salivation, etc.
Q5. Give an overview of the nervous system
Ans. Nervous system of animals has a complex structure that organizes their behavior and mediates sensory signals between different parts of the body. Mainly it receives and interprets the sensory signals from the surroundings and then sends out direct messages to the brain. The complexity depends on the organism's lifestyle and body plans.
