Control and Coordination Test -13

Thymus gland is larger in new born child which becomes smaller  with an increasing age.The thymus gland is a soft, flattened, pinkish-grey organ found in the upper chest under the breastbone. 

Fore brain contains cerebrum which in turn responsible for memory, will and intelligence of an individual.

Growth hormone (GH) deficiency cause dwarfism.This hormone is produced in the pituitary gland, which is located at the base of brain.

Human brain consists of large number of neurons. A neuron is an electrically excitable cell that processes and transmits information through electrical and chemical signals. 

The pons is a major structure in the upper part of your brainstem. It is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance.

The coccyx is a triangular arrangement of bone that makes up the very bottom portion of the spine below the sacrum.

Statement A is false because it produces  thyroid hormones into the bloodstream. Statement B is true because reflex action is a rapid automatic and involuntary response to a stimulus which is not under the control of the brain.

Insulin is a harmone made by the pancreas that allows your body to maintain blood sugar level in our body as diabetes mellitus is a condition of too much sugar in the blood

Progesterone levels also are extraordinarily high during pregnancy that cause a laxity and relaxin hormone produced by the ovary it relaxes the mother's muscles, joints and ligaments to make room for the growing baby

It causes the tendril to circle around the object and thus cling to it and Geotropism is the influence of gravity on plant growth or movement. 

Hormones are the chemical messengers that are produced by the endocrine system (composed of glands) but are transported to different parts of the body through the bloodstream.

The neural crest of the ectoderm develops into the peripheral nervous system, adrenal medulla, melanocytes, facial cartilage. The neural tube of the ectoderm develops into the brain, spinal cord, posterior pituitary, motorneurons, retina.

Movements which occur due to factors inherent inside the plant body itself is called as autonomic or spontaneous movements. Opening of floral buds to flowers is a type of autonomic movement of growth. Inner surface or upper surface of floral leaves expand towards outer side due to more cell growths. This makes the flower to open.

• The activities of the sensory organs are related to two types of neurons (afferent and efferent). 
• When the body receives an impulse, a signal is generated at the point of impact, which is sent to the brain through the neurons. The neurons, which pass nerve impulses from the body organ to the brain, is called an afferent neuron. 
• When it reaches the brain, it sends back a signal through the neurons to provide a reaction for a certain action. The neurons, which carry the nerve impulses from the brain to the body organs, are called efferent neurons.

The nervous system of human comprises of Central Nervous System - comprises of brain and spinal cord. Peripheral Nervous System - comprises of nerves present between brain and body parts.

Myelin sheath surrounds the axon of the nerve cell. It is a fatty white substance. It forms an insulating layer on the axon. It is formed by a process known as myelination. The gap between two myelin sheaths is known as the node of Ranvier. 

The cerebrospinal fluid is secreted by anterior choroid plexus and posterior choroid plexus and is found inside the ventricles of the brain and central canal of the spinal cord.

If the stem grows towards the sunlight, it is called as positively phototropic movement. It is a tropic movement induced in the plant, in response to the stimuli called as light. Whereas, the growth of root is negatively phototropic.

The normal functions of the brain's control centers are dependent upon the adequate supply of oxygen and glucose through a dense network of blood vessels which include the right and left common carotid arteries and right and left common vertebral arteries.