Control and Coordination | Important terms & definitions

Dear Students ! Please find all the key terms from the chapter control and coordination along with their meaning.

In case of any suggestions, please put it in the comment section below.

Terms	Meaning
Coordination	It is the process through which two or more organs interact and complement the functions of one another.
Neuron	Highly specialized cells which can detect, receive and transmit different kinds of stimuli.
Stimuli	A stimulus causes an action or response, in an organism. It can be external (temperature, light, etc. ) or internal (hunger, thirst, pain, etc.).
Receptor	The sensory receptors enables us to be aware of the environment around us. It responds to the stimuli.
Electrical impulse	Also known as the nerve impulse. It is the passing of electrical current from one end of the neuron to the other end, which actually carries the information.
Synapse	It is the junction place where two neurons communicate.
Synaptic cleft	The space between two neurons at a synapse, where the nerve impulse is transmitted through certain chemical structures.
Neurotransmitter	These are the chemical messengers that help in transmission of the nerve impulse between two neurons at synapse. The neurotransmitters are released by one neuron nerve ends, and it is received by the receptors present on the surface of dendrites of the other neuron.
Neuromuscular junction	It is a synapse between the neuron (motor neuron) and skeletal muscle. It helps in muscle contraction.
Reflex action	It is body’s immediate, involuntary response to an external stimulus to protect itself from the immediate harm. The brain is not involved directly as there is no thinking involved.
Reflex arc	The pathway taken by the reflex action is referred to as reflex arc. It normally involves the receptors, sensory neuron, relay neuron and motor neuron, finally reaching the effector organs.
Sensory neuron	These are a type of neuron that carries the nerve impulse from the sense organs to the CNS.
Motor neuron	Neurons that take away nerve impulse from the CNS to the effector organs like muscle or glands.
Relay neuron	Relay neurons are found in the brain and spinal cord and allow sensory and motor neurons to communicate.
CNS	Central Nervous System – consists of brain and spinal cord.
PNS	Peripheral Nervous System – has two components: the somatic nervous system and the autonomic nervous system
Cerebrum	The cerebrum is the largest part of the human brain. It is associated with higher brain function such as thought and action. The cerebral cortex is divided into four sections, called lobes – the frontal lobe, parietal lobe, occipital lobe, and temporal lobe.
Cerebellum	Part of the hind brain. It coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
Pons	The pons is a part of the brainstem. It is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance.
Medulla	The medulla oblongata is part of the hindbrain that controls autonomic functions such as breathing, digestion, heart/blood vessel function, and more.
Spinal cord	The spinal cord is a long, tube-like structure that begins at the end of the brain stem and continues down almost to the bottom of the spine. It consists of nerves that carry incoming and outgoing messages between the brain and the rest of the body.
Cranium	Also known as the skull that protects the brain from external injuries.
Tropic movement	The growth related movement exhibited by plants in response to an external stimulus. Hydrotropism, geotropism, phototropism, etc.
Nastic movement	The movements of plants parts in response to an external stimulus when the direction of response is not based on the direction of stimulus. It is not growth related. Thigmonasty (response to touch), photonasty (response to light), etc.
Geotropism	The movement of roots downwards in response to the gravitational force of earth. Roots exhibit positive geotropism whereas the shoots exhibit negative geotropism.
Hydrotropism	The movement of plant parts towards water or moisture. Root is positively hydrotropic.
Phototropism	The growth and movement of plant parts in response to light. Shoots exhibit positive phototropism while the roots exhibit negative phototropism.
Chemotropism	Response of plant parts towards certain chemical substance. Growth of pollen tube towards the style is an example of this.
Auxin	Plant growth hormone that helps the cells to grow longer/ cell elongation.
Cytokinin	Promotes cell division.
Gibberlin	Helps in growth of the stems.
Absisic acid	Inhibits growth. Involved in wilting of leaves.
Emergency hormone	Another name for the adrenaline.
Thyroxin	One of the most important thyroid hormone. It regulates carbohydrate, protein and fat metabolism in the body so as to provide the best balance for growth.
Growth hormone	Also known as somatotropin. It stimulates growth, cell reproduction, and cell regeneration in humans and other animals.
Insulin	Hormone released by the beta cells of the pancreas. It helps in bringing down the concentration of blood glucose level to maintain blood glucose homeostasis.
Glucagon	It is a hormone produced by alpha cells of the pancreas. It works to raise the concentration of glucose and fat in the bloodstream.
Glucose homeostasis	The maintenance of blood glucose level by the action of insulin and glucagon hormones.
Feedback mechanism	Mechanism by which the release and functioning of hormones are regulated.