Nervous System - Structure and function Flashcards
Three broad parts of the brain
Cerebrum, cerebellum and brain stem / medulla oblongata
Which hemisphere of the cerebrum controls the left side of the body?
Right hemisphere
Which functions does the left hemisphere of the cerebrum control for most people?
Speech
Logic
Math calculations
Pulling facts from memory
Which functions does the right hemisphere of the cerebrum control for most people?
Music
Face recognition
Spatial awareness
Where is information processed in the cerebrum?
Cerebral cortex - outermost layer where “gray matter” is found
What feature of the cerebrum increases its surface area?
Grooves
What are the lobes of the cerebrum?
Four regions in each hemisphere associated with different functions
Where is the cerebellum located?
Below and behind the cerebrum
What connects the two hemispheres of the cerebellum?
Vermis - worm-like mass of nerve tissue
How do the grooves of the cerebellum compare to those of the cerebrum?
More shallow and parallel
How is the white matter of the cerebellum arranged?
Like a branched tree
Function of the cerebellum
Controls voluntary movements, posture (muscle tone) and balance
C-shaped connector of the two hemispheres of the cerebrum
Corpus callosum
The corpus callosum consists of…
White matter; lots of axons
Which part of the brain is an extension of the spinal cord?
Medulla oblongata
How does the medulla oblongata differ from the brain?
Grey matter is inside, white is outside
Functions of the medulla oblongata
Transmit nerve impulses between the spinal cord and brain
Controls automatic functions
Location of the spinal cord
extends from medulla oblongata through the spinal canal of the vertebral column to the lumbar region
The spinal cord is composed of…
Grey and white matter
Layers of the spinal cord from the inside out
Central canal, H-shaped grey matter, white matter, spinal meninges
What connects to the spinal cord between successive vertebrae?
Bundles of neuron axons (nerves)
Two types of nerves in the peripheral nervous system
Sensory nerves and motor nerves
Function of sensory nerves
Conduct impulses from the receptors to the CNS
Function of motor nerves
Conduct impulses from the CNS to the effectors
Three main types of neurons
Interneuron
Sensory neuron
Motor neuron
Function of sensory neurons (afferent)
Receive information and send impulses to the spinal cord and brain
Function of motor neurons (efferent)
Conduct impulses from the spinal cord and brain to muscles/glands (effectors)
Function of the PNS
Conduct nerve impulses from receptors to the CNS along sensory neurons
Conduct nerve impulses from the CNS to the effectors along motor neurons
Function of the somatic nervous system
Conducts impulses from the CNS to voluntary (skeletal) muscles
Function of the autonomic nervous system
Conducts impulses from the CNS to involuntary (cardiac/smooth) muscles
How many pairs of cranial nerves are in the PNS?
12
How many pairs of spinal cord nerves are in the PNS?
31
Where do the cranial nerves connect to the CNS?
Brain
Where do spinal cord nerves connect to the CNS?
Spinal cord via dorsal and ventral roots
What is a nerve?
An enclosed, cable-like bundles of nerve fibres (axons) in the PNS
Function of a nerve
Provides a common pathway for the nerve impulses to and from peripheral organs
The three types of nerves
Afferent (sensory) nerves
Efferent (motor) nerves
Mixed nerves (carries axons of both afferent and efferent neurons)
The two sets of roots/nerves connecting to the spinal cord
Dorsal root and ventral root
Which root connects sensory neurons to the spinal cord?
Dorsal root
Which root connects motor neurons to the spinal cord?
Ventral root
Name of the bulge on the dorsal root
Dorsal root ganglion
Function of the dorsal root ganglion
Holds sensory neuron cell bodies
Two subdivisions of the autonomic nervous system
Sympathetic division and parasympathetic division
What is a reflex action?
A quick, automatic response of an effector to a stimulus
What is a reflex arc?
The pathway along which an impulse is transmitted to bring about a response to a stimulus during a reflex arc
Significance of a reflex action
Reflex actin allows for a quick response, without thinking about it, to prevent damage to the body
Significance of a synapse
Ensures impulse moves in one direction only
Prevents continuous stimulation of the neurons
Ensures that the impulse is transmitted from the sensory neuron to the motor neuron
Function of the sympathetic nervous system
Prepares the body for extra action (fight or flight)
When is the sympathetic nervous system engaged?
When you come across a threat
How does the sympathetic nervous system change your body processes?
Changes breathing, heart rate and releases glucose so that the body has extra energy
Function of the parasympathetic nervous system
Return the body to its resting state once danger has passed (rest and digest)
Alzheimer’s disesase
Progressive disorder which causes the brain cells to degenerate and die
Leads to memory loss and a decline in thinking
Causes of Alzheimer’s disease
Combination of genetic, lifestyle and environmental factors that affect the brain
Brain proteins do not function properly and cause neurons to be damaged and disconnected and this loss spreads predictably to other regions of the brain
Symptoms of Alzheimer’s
Worsening memory function Difficulty thinking and reasoning Poor judgement Difficulty planning/doing familiar tasks Changes in personality/behaviour
Multiple Sclerosis
Immune system attacks the myelin sheath which damages and deteriorates the nerves and causes communication problems between the brain and the rest of the body
