3.1 Neurobiology and immunology Flashcards
State the two divisions of the nervous system.
The nervous system can be divided into two main parts
· Central Nervous system (CNS)
· Peripheral Nervous System (PNS)
State the function of the nervous system
The function of the nervous system is to analyse sensory information from the body and the external environment detected by sensory neurones.It then stores some aspects of this information as memories and makes decisions regarding appropriate responses and behaviours. These responses and behaviours are triggered through motor responses that initiate either muscular contractions or glandular secretions.
Identify the structures of the central nervous system (CNS)
The central nervous system is composed of the brain and the spinal cord.
Identify the systems of the Peripheral Nervous System (PNS).
The peripheral nervous system consists of the somatic nervous system (SNS) and the autonomic nervous system (ANS).
Identify the structures of the Somatic Nervous System (SNS).
The somatic nervous system (SNS) is made up of sensory neurones and motor neurons.
What does the sensory neurons do
Sensory neurons carry impulses from the sense organs to the CNS.
Motor neurons carry impulses from the CNS to muscles and/or glands.
The sensory and motor neurons of the somatic nervous system (SNS) control the voluntary movement of the skeletal muscles.
Identify the systems of the Autonomic Nervous System (ANS)
The sensory and motor neurons of the autonomic nervous system (ANS) bring about homeostatic control through involuntary impulses to smooth muscle, cardiac muscle and glands. The ANS works automatically (without the involvement of conscious thought). Impulses originate from the in the medulla region of the brain. The autonomic nervous system (ANS) is made up of the sympathetic and parasympathetic systems.
Compare the actions of the Sympathetic and Parasympathetic Nervous Systems. (sympathetic)
The sympathetic system speeds up heart rate and breathing rate while slowing down peristalsis and production of intestinal secretions. This system prepares the body for ‘fight or flight’ responses. (Sympathetic Speeds up heart rate /breathing rate)
Compare the actions of the Sympathetic and Parasympathetic Nervous Systems. (parasympathetic)
The parasympathetic system slows down heart rate and breathing rate while speeding up peristalsis and the production of intestinal secretions. This system prepares the body for ‘rest and digest’ responses. (Parasympathetic Promotes Peristalsis)
How do the sympathetic and parasympathetic systems work
The sympathetic and parasympathetic systems are antagonistic – they work in opposition to each other.
Identify the three types of neural pathways
Converging
· Diverging
· Reverberating
Converging
In a converging neural pathway, impulses from several neurons travel to one neuron. This increases the sensitivity to excitatory or inhibitory signals e.g. the convergence of neurons from rods in the retina so increasing sensitivity to low levels of illumination through summation.
Diverging
In a diverging neural pathway, impulses from one neuron travel to several neurons so affecting more than one destination at the same time e.g. the divergence of motor neurons which allows fine motor control of fingers
Reverberating
In a reverberating pathway, neurons later in the pathway link with earlier neurons, sending the impulse back through the pathway. This allows repeated stimulation of the pathway. E.g. the use of reverberating pathways in repetitive activities such as breathing
