Nervous System Flashcards
Two parts of the nervous system
Central Nervous System CNS - Spine and brain
Peripheral nervous system - peripheral sensory nevrves
Functions of the CNS and PNS
Receives sensory information about the external environment
CNS integrates and processes this information
Sends nerve impulses to the intended organs, muscles and glands
PNS changes the internal environment to maintain homeostasis
4 Lobes of the cerebrum
The Frontal Lobe –
Personality, thoughts, movement control
The Parietal Lobe –
information about temperature, taste, touch and movement
The Occipital Lobe –
Vision and interpretation
The Temporal Lobe –
processes memories, integrating them with sensations of taste, sound, sight and touch.
what does the cerebrum control
Controls: Most of our senses Intelligence Personality Conscious thought High level functions such as language and verbal memory
What does the cerebellum control
Not under voluntary control – but gathers sensory information from muscles, joints and 5 senses
Controls the maintenance of: Balance Muscle co-ordination Muscle tone Learning and language.
4 component parts of the brain
Cerebellum
Cerebrum
Diencephalon
Brain Stem
3 Parts of the Diencephalon
Pineal body/gland
Thalamus
Hypothalamus
Function of the Diencephalon
Temperature control Sensory functions of touch and pain Hunger and thirst Emotion Circadian cycles Is the main hormone control centre for the nervous system.
3 parts of the brain stem
Mid Brain
Pons
Medulla oblongata
Location / Purpose of the Mid Brain
Connects upper parts of brain and lower parts of brain and spinal cord
Contains important reflex centres affecting the eyes, head and neck.
Location and purpose of the Pons Varolii
Situated in front of the cerebellum, below mid brain
Joins cerebrum above to medulla and cerebellum below.
Mainly nerve fibres
Forms a bridge joining various parts of the brain to one another
Purpose of the medulla oblongata
Regulates vital actions, such as respiration and circulation
It is also the centre for reflex actions such as swallowing, vomiting, coughing and sneezing
Location and role of the cardiovascular centre
Located in the medulla
Controls the rate and force of cardiac contraction
Controls blood pressure
Diameter of blood vessels
The diameter is controlled through the vasomotor in the CVC which reacts to baroreceptors, chemoreceptors, body temperature, emotions, pain, etc.
Location and role of the respiratory centre
Located in the medulla and the pons.
This controls the rate and depth of respiration
Nerve impulses are passed which stimulate contraction of the diaphragm and intercostal muscles initiating inspiration.
Define Decussation
This means the left hemisphere of the brain controls the right half of the body and vice versa
Function of the meninges
Protect the brain and spinal cord
Maintains the brains position
Absorbs excess cerebrospinal fluid
Three layers of the meninges
Dura Mater
Arachnoid Mater
Pia Mater.
Features of the Dura Matter
tough fibrous membrane, that contains interstitial fluid. Lines the surface of the skull bones, and provides a loose sheath around the spinal cord
Features of the arachnoid matter
delicate serous (permeable) membrane, with the sub-dural space above, and the sub-arachnoid space below. The sub-arachnoid space contains CSF.
Features of the Pia matter
delicate inner membrane, richly supplied with blood vessels and is adherent to the surface of the brain.
Location of the spinal cord
begins at the end of
the brain stem and continues down almost
to the bottom of the spine terminating at
L1-L2
Functions of the spinal cord
The spinal cord communicates information.
A spinal cord injury can undermine even
the most basic functions.
Functions of Cerebrospinal fluid
Lubricate the brain and spinal cord preventing friction during movement
Supports the brain
Nourish and cleanse by washing away waste and toxic substances
Act as a shock absorber.
Cerebrospinal Fluid maintains homeostasis in 3 ways
Mechanical protection
Shock absorber
Floats the brain in the cranial cavity
Chemical protection
Providing an optimal chemical environment, including nutrients
Optimum chemical environment for neuronal singling
Circulation protection
CSF is a medium for the exchange of nutrients and waste products
This occurs between blood and nervous tissue.
Define a reflex action
A reflex action is an involuntary and immediate motor response to a sensory stimulus
Two types nerves in the peripheral nervous system
Sensory nerves (afferent nerves) – transmit impulses to the CNS
Motor nerves (efferent nerves) – transmit impulses from the CNS to the body
Examples of sensory nerves
5 senses
Chemoreceptors
Baroreceptors
Osmoreceptors
Types of motor nerves
Somatic - voluntary -
Automatic. - involuntary
How many peripheral nerves are there?
The 31 peripheral nerves:
Cervical (8) Thoracic (12) Lumbar (5) Sacrum (5) Coccygeal (1)
Number and function of cranial nerves
Twelve pairs
Relay sensory information to specialised areas of the brain
Relay information relating to touch temperature and pain from the head and neck
Control motor functions of muscles around head and neck
Autonomic control of many internal functions.
Purpose of Autonomic nervous system
Supplies nerves to all the internal organs of the body and blood vessels
Controls involuntary movements of organ and glands and involuntary muscles
Two nerves within the autonomic nervous system, and functions
Sympathetic nerves stimulate and quicken the heart, circulatory and respiratory systems but inhibit peristalsis (Fight or Flight)
Parasympathetic nerves stimulate the digestion and slow the heart, in turn reduces circulation and respiration. (Rest and Digest)
