Case Based Questions: Control and Coordination

Case Study - 1

In animals, such control and coordination are provided by nervous and muscular tissues. Touching a hot object is an urgent and dangerous situation for us. We need to detect it, and respond to it. How do we detect that we are touching a hot object? All information from our environment is detected by the specialised tips of some nerve cells. These receptors are usually located in our sense organs, such as the inner ear, the nose, the tongue, and so on. So gustatory receptors will detect taste while olfactory receptors will detect smell.

Q1: What are the parts of neuron?
Ans: Dendrite, nucleus, axon, nerve ending and a cell body.

Q2: Which part of neuron receive the information first?
Ans: Dendritic tip receive the information first.

Q3: At which place the electrical impulse get converted to a chemical impulse?
Ans: At synapse or a gap between nerve ending and a dendritic tip.

Q4: What is neuromuscular junction?
Ans: The neuromuscular is made up of two words neuron & muscles, so it is the place where neuron and muscle fibre meet.

Case Study - 2

Body consists of dense networks of intricately arranged neurons. It sits in the forward end of the skull, and receives signals from all over the body which it thinks about before responding to them. Obviously, in order to receive these signals, this thinking part of the brain in the skull must be connected to nerves coming from various parts of the body.

Q1: What is reflex?
Ans: It is the sudden action done in response to something in the environment.

Q2: How does the nervous tissue cause action?
Ans: When a nerve impulse  reaches the muscles, the muscles fibres move by changing their shape and their arrangements in the cell.

Q3: What is the function of the motor neuron?
Ans: It transmits the impulses from spinal cord to skeletal muscles.

Q4: What is reflex arc?
Ans: It is the neural pathway that controls reflex starting from a sensory neuron and end at effector.

Q5: What is the role of sensory neuron?
Ans: It carry signals from outer part of body to central nervous system.

Case Study - 3

We also think about our actions. Writing, talking, moving a chair, clapping at the end of a programme are examples of voluntary actions which are based on deciding what to do next. So, the brain also has to send messages to muscles. This is the second way in which the nervous system communicates with the muscles. The communication between the central nervous system and the other parts of the body is facilitated by the peripheral nervous system consisting of cranial nerves arising from the brain and spinal nerves arising from the spinal cord. The brain thus allows us to think and take actions based on that thinking.

Q1: What are the three major parts of the brain?
Ans: Forebrain, Midbrain and hindbrain.

Q2: What are the function of medulla?
Ans: It controls all the involuntary action such as blood pressure, salivation, vomiting, etc.

Q3: Which fluid is present in our brain?
Ans: Cerebrospinal fluid.

Q4: What is the function of hypothalamus?
Ans: It regulates homeostasis, releases hormones.

Q5: What is the function of mid brain?
Ans: The mid brain connects the forebrain and hindbrain.

Case Study - 4

Some plants like the pea plant climb up other plants or fences by means of tendrils. These tendrils are sensitive to touch. When they come in contact with any support, the part of the tendril in contact with the object does not grow as rapidly as the part of the tendril away from the object. This causes the tendril to circle around the object and thus cling to it. More commonly, plants respond to stimuli slowly by growing in a particular direction. Because this growth is directional, it appears as if the plant is moving.

Q1: How many type of tropism are shown by plants? Name them.
Ans: Generally there are 6 type of tropism namely phototropism, gravitropism, chemotropism, thigmotropism, thermotropism and hydrotropism.

Q2: The touch me not plant is an example of which tropism?
Ans: It is an example of thigmotropism.

Q3: Give one example of chemotropism?
Ans: Growth of pollen tubes to wheels is one example of chemotropism.

Q4: Name the plants hormone which promotes cell division?
Ans: Cytokinins promotes cell division in plants.

Q5: Name the plant hormone which inhibits growth?
Ans: Abscisic acid

Case Study - 5

If the body design in the squirrel relied only on electrical impulses via nerve cells, the range of tissues instructed to prepare for the coming activity would be limited. On the other hand, if a chemical signal were to be sent as well, it would reach all cells of the body and provide the wideranging changes needed. This is done in many animals, including human beings, using a hormone called adrenaline that is secreted from the adrenal glands.

Q1: Which is the target organ for the adrenaline hormone?
Ans: Heart is the target organ for the adrenaline hormone which increases the heartbeat rate.

Q2: Which hormone is released by thyroid gland?
Ans: Thyroxine is released by thyroid gland.

Q3: What is the function of thyroxine hormone?
Ans: It regulates carbohydrate, protein and fat metabolism in the body and promote the best balance for growth.

Q4: Name the hormone released by ovary?
Ans: Estrogen and progesterone

Q5: Name the three hormonal glands located in the brain?
Ans: Pineal, pituitary and hypothalamus