Chapter 2A Flashcards
The human nervous system
Nervous system
The nervous system is a organized network of nerve tissue in the body, it contains the central nervous system which includes the brain and the spinal cord, and then the peripheral nervous system which includes the somatic and autonomic nervous system including the sympathetic and parasympthetic nervous systme
Central nervous system
The central nervous system (CNS) comprises the brain and spinal cord. It processes sensory information, coordinates movement, manages cognition and emotions, and regulates vital functions like heart rate and body temperature. Protected by the skull, vertebral column, and meninges, the CNS is crucial for controlling and integrating bodily functions.
The brain
- the brain is responsible for processing information and initiating actions
- it is responsible for maintaining physiological and psychological functioning
The spinal cord
- the spinal cord is a thick bundle of Neurons that allows the brain to communicate with the rest of the body and vice versa
- Neurons branch off to various muscles, organs and glands
peripheral nervous system
The peripheral nervous system (PNS) connects the central nervous system (CNS) to the rest of the body. It consists of sensory and motor neurons that extend beyond the brain and spinal cord, transmitting information to and from the CNS. The PNS is divided into the somatic nervous system, which controls voluntary movements and sensory information, and the autonomic nervous system, which regulates involuntary functions like heart rate and digestion.
somatic NS
- the somatic NS is responsible for voluntary movements initiated by the brain
- it also transmits sensory information to the brain for processing
- it controls skeletal muscles
Autonomic NS
- this division of the peripheral NS is responsible for involuntary functioning- those functions that we don’t have to think about
- it controls visceral/smooth muscles, organs and glands
sympathetic NS
- this division prepares the body to react to danger or stress
- it heightens survival functions and slows functions not vital for survival
parasympathetic NS
- this division is dominant most of the time and maintains optimal functioning of the body
- it is responsible for returning the body to normal levels after the sympathetic NS has been activated
sensory neurons
these neurons take sensory information from the environment (i.e getting poked with a needle) and sends the signal to the brain
motor neurons
these neurons communicate information from the brain to tissues and organs throughout the body allowing movement
interneuron
these neurons make up the majority of neurons in the body. they are essentially the middle man transmitting information between sensory and motor neuron. they play a key role in learning memory and planning
diagram of a neuron
- nucleus
- dendrites
-axon - terminal buttons
- axon terminals
Alternative terminology (SAME)
We use the term sensory to describe neurons that send information to the CNS. Al alternative term that you might see is AFFERENT
The motor neuron sends neural messages to the skeletal muscles. They can also be referred to as EFFERENT.
sensory = afferent
motor = efferent