Control and Coordination – Class 10 Review

A comprehensive set of question-and-answer flashcards covering stimuli, neuronal structure, nerve impulse transmission, divisions and functions of the human nervous system, brain regions, reflex actions, plant hormones, and major human endocrine glands and their hormones.

What is a stimulus in the context of living organisms?

Any change in the environment (e.g., light, heat, sound) that elicits a response from an organism.

Which two systems jointly maintain control and coordination in animals?

The nervous system and the hormonal (endocrine) system.

What is the functional and structural unit of the nervous system?

The neuron (nerve cell).

Name the three main parts of a typical neuron.

Cell body (cyton with dendrites), axon, and myelin sheath.

Which part of a neuron receives incoming nerve impulses?

Dendrites on the cell body (cyton).

What is the insulating covering around many axons called?

The myelin sheath.

Which type of neuron carries signals from sense organs to the central nervous system?

Sensory neuron.

Which type of neuron transmits signals from the CNS to muscles or glands?

Motor neuron.

Which neuron relays signals between sensory and motor neurons?

Association (relay) neuron.

What is the point of contact between the axon terminal of one neuron and the dendrite of another neuron called?

Synapse.

Define a neuromuscular junction (NMJ).

The point where a motor neuron’s axon terminal meets a muscle fibre to transmit impulses.

State the correct pathway of a nerve impulse through a single neuron.

Dendrites → cell body → axon → axon terminals.

Into which two major divisions is the human nervous system classified?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Which organs make up the central nervous system?

The brain and the spinal cord.

Which part of the nervous system controls voluntary actions?

The Somatic Nervous System (SNS).

Which branch of the autonomic nervous system prepares the body for “fight or flight”?

The sympathetic nervous system.

What are the three protective membranes surrounding the brain collectively called?

The meninges.

Which fluid cushions the brain against mechanical shock?

Cerebrospinal fluid (CSF).

Name the three major regions of the human brain.

Forebrain, midbrain, and hindbrain.

Which part of the brain is responsible for intelligence, memory, and consciousness?

The cerebrum (in the forebrain).

Which forebrain structure regulates body temperature, hunger, and thirst?

The hypothalamus.

Which hindbrain part maintains posture and balance of the body?

The cerebellum.

Where are the centres for respiration and cardiovascular reflexes located?

In the medulla oblongata (hindbrain).

What is a reflex action?

A sudden, involuntary, and automatic response to a stimulus.

List the components of a reflex arc in correct order.

Receptor → Sensory neuron → Relay neuron → Motor neuron → Effector (muscle/gland).

Why do reflex actions not involve the brain?

To allow quicker responses by routing the impulse through the spinal cord only.

How do plants achieve control and coordination without a nervous system?

Through chemical messengers called plant hormones (phytohormones).

Which plant hormone promotes cell division?

Cytokinins.

Which plant hormone inhibits growth and causes wilting of leaves?

Abscisic acid (ABA, the stress hormone).

What are hormones in animals?

Chemical messengers secreted in minute amounts by ductless (endocrine) glands that act on distant target organs.

Which gland is called the ‘master gland’ and why?

The pituitary gland, because it secretes hormones (e.g., GH, TSH, FSH) that regulate the activity of other endocrine glands.

Which hormone controls blood sugar levels?

Insulin secreted by the pancreas.

Which hormone prepares the body for emergency situations?

Adrenalin from the adrenal glands (the “fight and flight” hormone).

What is the main function of thyroxine?

To regulate general metabolism and growth of the body.

Which hormone stimulates overall growth in humans?

Growth hormone (GH) from the pituitary gland.

Name the male sex hormone and state one function.

Testosterone; it promotes sperm production and development of secondary sexual characters.

Name the female sex hormone and state one function.

Oestrogen; it regulates egg production and development of secondary sexual characters.