Peripherial Nervous System - Cranial & Spinal Nerves Flashcards
What does the peripheral nervous do?
The PNS detects changes in the internal and external environment through sensory receptors located throughout the body and relays sensory information via afferent (sensory) nerve fibers to the CNS. Signals from the CNS are sent through efferent (motor) nerve fibres in cranial and spinal nerves to trigger motor responses in gland and muscle tissue
What does the PNS consist of?
The PNS consists of Nerve Fibres and cell bodies outside of the central nervous system. It is organised into nerves which connect the CNS with the body.
How many pairs of cranial nerves are there?
12
How many pairs of spinal nerves are there?
31
What does the PNS consist of?
The PNS consists of everything outside of the brain and spinal cord. This includes:
- Sensory receptors
- afferent and efferent nerves
- ganglia
- motor endings.
What do sensory receptors do and where are they?
They are located throughout the body and relay sensory info via afferent (sensory) nerve fibres to the CNS.
What does the Peripheral nervous system consist of?
It consists of the cranial and spinal nerves and the special sense organs.
What is the motor function of the PNS and what type of fibres are they?
They are efferent (motor) nerve fibres which are in the cranial and spinal nerves which trigger motor responses in gland and muscle tissue.
Outline the Spinal nerve formation components.
The dorsal and ventral rootlets (connect to the top and bottom of the spinal cord)
The Dorsal Root ganglion
The Ventral root
The Spinal nerve
the Dorsal and Ventral Ramus/Rami
What does the Dorsal Rami do?
It supplies synovial joints of the spine, deep spinal muscles and skin upon them.
What does the ventral rami do?
supplies the muscles and skin of limbs and anterior and lateral trunk
