Nervous System 1 Flashcards
What are the 2 parts of the nervous system
-central nervous system consists of the brain and spinal cord
-peripheral nervous system consists of the peripheral nerves that exit the spinal cord to the rest off the body
What does white and grey matter consist of
Grey - neutral cell bodies, axon terminals, and dendrites as well as nerve synapses
White - brain and spinal cord is composed of bundles of axons, these are coated with myelin
What 2 functions do the peripheral nerves have
-respond to sensory stimuli and carry sensory information from all over the body to the cns
-some carry info from the cns back to the rest of the body
What 2 functions do the peripheral nerves have
-respond to sensory stimuli and carry sensory information from all over the body to the cns
-some carry info from the cns back to the rest of the body
What roles does the sympathetic and parasympathetic nervous systems have
Sympathetic- dilate pupils, relax airways and bladder, increase pulse, secrete epinephrine
Parasympathetic- constrict pupils, contract airway and bladder, slow heartbeat
List 3 structures of a neuron
-have a long fibre (axon)
-cell body contains nucleus
-the end of the axon (axon terminal) contains many nerve endings
What do dendrites do
Form connections with many other neurons
What 5 elements create the structure of a sensory neuron
-receptor cell
-dendron
-myelin sheath
-cell body
-axon
What 3 elements create the structure of a relay neuron
-dendrite
-cell body
-axon
What 4 elements create the structure of a motor neuron
-cell body
-nodes of ranvier
-axon
-Schwann cells
What do sensory neurons do
Transmit nerve impulses from a receptor to a relay or motor neuron
What do motor neurons do
Transmit nerve impulses away from a relay neuron to an effector such as a gland or muscle
What do relay neurons do
Transmit impulse between neurons, sensory to motor is an example of
What is the structure and function of the cell body
Contains all the organelles including the nucleus and a large amount of rough ER to produce proteins and neurotransmitters
What is the structure and function of dendrons
Extensions of the cell body which subdivide into smaller branches fibres called dendrites that carry nerve impulses towards the cell body
What is the structure and function of the axon
The long single fibre that carries nerve impulses away from the cell body towards the axion terminal
What is the structure and function of the schwann cells
Surround the axon providing protection and electrical insulation. They are wrapped in layers around the axon
What is the structure and function of the myelin sheath
Forms a covering to the axon and is made up on the m,embraces of the Schwann cells. Membranes are made of myelin which is rich in lipids-neurons with this sheath are known as myelinated neurons (white matter)
What is the structure and function of nodes of ranvier
Constrictions between adjacent Schwann cells where there is no myelin sheath. They are 2-3um long and occur every 1-3mm in humans
What are transducers
Receptor cells that convert sensory information into electrical energy for the specific stimulus the detect
