Chapter 12: Integration of Nervous System Functions

This chapter is a great opportunity for us to realize the miraculous blessing that was given to us. The human brain is a miracle because it is the reason of thinking and the reason of everything. This blog will encourage us more to acknowledge what we have.


The human brain is capable of unique and complex functions, such as recording history, reasoning, and planning, to a degree unparalleled in the animal kingdom. Many of these functions can only be studied in humans. That is a major reason why much of human brain function remains elusive and why it remains one of the most challenging frontiers of anatomy and physiology.


Sensation, or perception is the conscious awareness of stimuli received by sensory receptors. 
Receptors are sensory nerve endings or specialized cells capable of responding to stimuli by developing action potentials.

Receptors include mechanoreceptors, chemoreceptors, photoreceptors, thermoreceptors, and nociceptors.

Free nerve endings detect pain, temperature, itch, and movement (proprioception).


Sensory Tracts
 Ascending pathways carry conscious and unconscious sensations. Each pathway carries specific sensory information because each pathway is associated with specific types of receptors.

Here is a video that you can watch to understand how the sensory tracts works:




Sensory Areas of the Cerebral Cortex
1. Sensory pathways project to primary sensory areas (visual, auditory, taste, olfactory, and somatic sensory) in the central cortex.
2. Sensory areas are organized topographically in the somatic sensory cortex.


Sensory Processing
Association areas of the cerebral cortex process sensory input from the primary sensory areas.

Watch the video here to understand more on how the sensory process takes place:
Other Brain Functions

Speech 
 Speech is located only in the left cortex in most people.
 Wernicke's area comprehends and formulates speech,
 Broca's area receives input from Wernicke's area and sends impulsesto the premotor and motor areas, which causes the muscle movements required for speech.


Memory
At least three kinds of memory exist: sensory, short-term, and long-term.


Effects of Aging on the Nervous System
1. There is a general decline in sensory and motor functions as a person ages.
2. Short-term memory is decreased in most older people.
3. Thinking ability does not decrease in most older people.


And that ends our topic about the integration of the nervous system.. Hope you learn something about it..

END of Chapter 12