Control and Coordination — Important Questions

Adrenal gland

Step 1: Adrenal glands are small triangular-shaped glands located on top of both kidneys. Step 2: When we face emergency situations like fear or danger, these glands secrete adrenaline. Step 3: Adrenaline is called the 'fight or flight' hormone as it prepares body for action. Step 4: It increases heart rate, breathing rate, and diverts blood to muscles. Step 5: Thyroid secretes thyroxin, pituitary secretes growth hormone, and pancreas secretes insulin.

Synapse

Step 1: Neurons do not physically touch each other; there is a small gap between them. Step 2: This gap is called a synapse, which ensures controlled transmission of signals. Step 3: When an electrical impulse reaches the end of an axon, it releases chemicals called neurotransmitters. Step 4: These chemicals cross the synapse and create a new electrical impulse in the next neuron. Step 5: Dendrites receive signals, axons transmit signals, and impulse is the electrical signal itself.

Cerebellum

Step 1: The cerebellum is located at the back of the brain, below the cerebrum. Step 2: It receives information from sensory organs about body position and muscle activity. Step 3: It processes this information and coordinates muscle movements for balance and posture. Step 4: Activities like walking straight, riding a bicycle, or picking up objects require cerebellum function. Step 5: Cerebrum handles thinking, medulla controls involuntary actions, and spinal cord transmits messages.

Pancreas

Step 1: The pancreas is located behind the stomach and has both digestive and hormonal functions. Step 2: Special cells in the pancreas called islets of Langerhans produce insulin hormone. Step 3: Insulin helps regulate blood sugar levels by allowing glucose to enter cells. Step 4: When blood sugar rises after eating, pancreas releases insulin to bring it back to normal. Step 5: Liver stores glucose, kidneys filter blood, and stomach digests food, but none produce insulin.