The Mammalian Nervous System 5.5.8 Flashcards
What does the human nervous system consist of?
Central nervous system
Peripheral nervous system
What is the main function of the nervous system?
This communication system controls and coordinates functions throughout the body and responds to internal and external stimuli.
What does the nervous system consist of?
Brain, spinal cord, nerves, and sense organs
What are the sense organs?
Eyes, ears, skin, nose, and tongue
What does the central nervous system consist of?
Brain and spinal cord
What does the peripheral nervous system consist of?
Sensory system and motor system
What is in the motor system?
Somatic nervous system and autonomic nervous system
What does the peripheral nervous system include?
All sensory neurones, motor neurones, and sense organs
What are sensory fibres?
Sensory fibres entering the CNS are dendrons of sensory neurones
What is found in the dorsal root that leads into the spinal cord?
The cell body of sensory fibres
What is the somatic nervous systems function?
Conducts action potentials from the CNS to effectors under voluntary control
Give an example of an organ in the somatic nervous system?
Skeletal muscles
Why do most neurones in the somatic nervous system have fast transmission?
As they are myelinated
What is the function of the autonomic nervous system?
Conduct action potentials from the CNS effectors that are not under voluntary control
Give examples of effectors in the autonomic nervous system
Glands, cardiac muscle, smooth muscle in walls of blood vessels, airways and wall of the digestive system
How many neurones are connected in the autonomic nervous system and where?
At least 2 neurones are involved in the connection between the CNS and the effector, at ganglia
What does the autonomic nervous system control the majority of?
Homeostatic mechanisms
What can the autonomic nervous system be divided into?
Sympathetic
Parasympathetic
What does the sympathetic nervous system do, briefly?
Prepares the body for activity
What does the parasympathetic nervous system do, briefly?
Conserves energy
What are both the sympathetic and parasympathetic nervous systems in general?
Antagonistic systems.
At rest, action potentials pass along the neurones of both systems at relatively low frequency
What leads to changes in the balance of stimulation between the parasympathetic and sympathetic nervous systems?
Changes to internal conditions or stress
When is the sympathetic NS most active?
During times of stress
When is the parasympathetic NS most active?
During sleep or relaxation
