The body and its constitutes

Question 1

Internal Communication - Nervous System CNS

Answer 1

CNS: the brain: protected by the skull
spinal cord: extends from the base of the skull to the lumber region, bones of the spinal column

Question 2

Peripheral nervous system

Answer 2

• a network of nerve fibres
• sensory nerves - transmit signals from the body - brain
• motor - transmitted signals from the brain to affected organs, e.g. glands
• somatic sense = pain, touch, heat. - stimulation of sensory receptors and nerve endings = muscles & joints respond to change in position & orientation = maintain balance and posture
  Sensory receptors are activated by stimuli in internal organs and control body functions, such as heart rate and blood pressure.
• electrical impulses - generated by nerve endings = stimulated
• nerve endings (action potential) travel 100 meters per second = fast reaction to body functions
• nerves communicator - release chemical (neurotransmitter) - small gaps = simulation or inhabits the next nerve = transmitting a message.

Question 3

Brain

Answer 3

• brain responds - sending impulses along monitor = nerves to organs
• bodily functions are monitored & adjusted by negative feedback control e.g. blood pressure
• reflex action = fast, involuntary & protective nerve response to specific stimulus e.g. withdraw of fingers from a hot surface.

Question 4

Endocrine system

Answer 4

• synthesis & secret chemical messages = hormones
• circulate the body in the bloodstream
• Hormones stimulate target glands or tissue
• influence metabolic & other cellular activities
• regulate body growth & maturation
• detect & respond to levels of substance
• change in hormone level controlled by a negative feedback mechanism
• the endocrine system provides slower control of body functions than the nervous system