Human Nervous System Flashcards
What is the nervous system
The body’s control and communication centre
What is the purpose of the nervous system
It provides a continuous flow of information which enables us to perform every tasks
What are the major functions of the nervous system
Sensory, integrative and motor function
What is the sensory function of the Nervous System
Sensory receptors detect changes in the external/internal environment
What is Integrative function of the Nervous System
The CNS receives info and decides which effectors need to react to the stimulus
What is the Motor function of the Nervous System
Effectors bring about appropriate responses
What is Stimuli
Physical or chemical changes in the environment that can cause a response in an organism
What is an example of an internal stimuli
Blood pressure
What is an example of external stimuli
Temperature
What is the CNS made up of
The Brain and Spinal cord
What is the CNS responsible for
For processing all info from our senses , and directing our movements and thoughts
How is the CNS protected
By three connective tissue membranes called Meninges and cerebro-spinal fluid and is enclosed with the cranium
What is the function of the cerebro-spinal fluid
Protects the CNS against shock and damage
What is the function of the cranium
It protects the brain against mechanical injuries
What are the meninges
Inner pia mater
Thin arachnoid membrane
Tough dura mater
What prevents jarring of the CNS, giving the body spring resilience
S-shape curvature of vertebral column n cartilaginous disks
What is the brain
The enlarged upper part of the spinal cord enclosed with the cranium
Parts of the brain
The Cerebrum, Cerebellum, Hypothalamus and Medulla oblongata
The Cerebrum
Has two cerebral hemispheres held together by the corpus callosum
What does the Corpus callosum do
Provides communication between hemispheres and the cerebral cortex and lower part of the CNS
What is the surface area of the Cerebrum made up of
Gyri( folds) and sulci (grooves)
What do Gyri and sulci fo
Enlarge the surface area so a large amount of brain cells can fit into a small cranial cavity
What is the Cerebral cortex
It’s the outer 3mm of Cerebrum made up of grey matter because of neuroplasm
What is the white matter
It’s below the grey matter, made up of mylinated nerve fibres ( fatty myelin- yt)
Motor functions of the Cerebrum
In the frontal lobe
Voluntary movements
Sensory functions of the Cerebrum
Receive and interpret impulses
Hearing, smelling & tasting in the temporal lobe
Sight in the occipital live
Skin feel in the parietal lobe
Function of the association cortex
Higher mental activities- frontal lobe
Intelligence, memory etc
Integrate and store info before it’s sent to motor areas
Where does the Cerebellum lie
Below the cerebruh
What is the arrangement of grey and white Matter of the Cerebellum
White matter looks like branches and is surrounded by the Grey matter which looks like the foliage
What are the functions of the Cerebellum
It controls coordination and balance
Where is the Hypothalamus
It lies below the thalamus and above the pituitary gland
What are the functions of the Hypothalamus
Helps maintain homeostasis by maintaining body temperature, food intake n water balance
Is the centre for survival emotional response and behaviour
It secretes ADH n controls the release of all the hormones from pituitary gland
Where is the Medulla oblongata
Forms the lowest part of the brain stem
What is it Called when it passed the foramen magnum
The spinal cord
What are the functions of the Medulla Oblingata
Serves as a pathway for impulses to n from the brain
Acts as a Reflex centre
What reflexes does the Medulla Oblongata help control
Breathing, blood pressure by regulation vasodilation and vasoconstriction
Swallowing
Yawning
Coughing
What is Vasodilation
It is the widening of blood vessels
What is vasoconstriction
The narrowing of blood vessels
What does yawning do
It forces cool air into your body
What does coughing do
It helps open up breathing
What does the Corpus Collasum do
It separates left from right
What is the Spinal Cord
An elongated rod of nervous tissue that extends from the medulla oblongata through the foramen magnum situated in the vertebral canal
What happens at the Spinal Cord
The meeting if the CNS and the PNS
What are meninges
A thin tissue layer protecting the spinal cord
What are intervertebral discs
Carteligenous parts between vertebrae
What’s the function of intervertebral discs
Shock absorption
Allow bending
How many bones does the vertebrae have
33
What is the central Canal
It runs through the spinal cord in the centre of the grey matter
Filled with cerebro-spinal fluid
What is the Grey matter made of
Nerve cell bodies
Dendrites
Synapses
What is the White matter and what is it made of
It’s the fatty layer surrounding grey matter
Made up of axons with myelin sheaths
How many pairs of spinal nerves are there
31 pairs
What is the dorsal groove
)
)
Shallow
What is the ventral groove
It’s deep
What is the dorsal root
Has sensory monopolar nerves coming in
Afferent
Has ganglion
What is the ventral root
Has motor multipolar nerves going out
Efferent
What is the dorsal ganglion
Has a small mass of neuron cell bodies
What are the functions of the spinal cord
Pathway for impulses from receptors to brain to effectors
Spinal reflexes- very quick, think about after
What is the Peripheral Nervous System made up of
Nerves that link the CNS to the receptors and effectors
What are the 43 pairs of nerves
12 pairs- cranial connected to brain
31 pairs of spinal nervous entering & leaving the spinal cord
What are the functions of the PNS
Motor functions
Sensory functions
What are the sensory functions of the PNS
Collects info from receptors, transmits it via impulses along neurons to the CNS
What are the motor functions of the PNS
Transmits impulses from CNS to effectors to bring about responses
What is the motor division made up of
Somatic Nervous System
Autonomic Nervous System
What is the SNS
Conducts impulses from CNS ti skeletal muscle & therefore controls all voluntary muscular movements
What is the ANS
Conducts impulses from the CNS to cardiac muscle, smooth muscles and glands & therefore controls involuntary muscles of glands
Maintains homeostasis
What is voluntary
With conscious control by the brain
What is involuntary
Without conscious control
What is the ANS made up of
Sympathetic Nervous System
Parasympathetic Nervous System
What does the Sympathetic do
Works together with adrenalin in emergency situations that cause stress
Fight and flight
More oxygen, glucose & blood sent to skeletal muscles where cellular respiration is speeded up to release more energy for action
What does the Parasympathetic do
Enables body to ‘rest and digest’
To recover from sympathetic stimulation- return to normal
What does the ANS do in response to changing conditions
Speeds/ slows heart & respiratory rate
Adjusts blood pressure & temperature
Shunts blood to where it’s needed
Decreases/increases digestive secretions
Double innervation
Organs innervated with nerves from both systems
What is a coordinating system
A system that allows communication between the receptors and the effectors of the body to bring about appropriate reactions to the stimuli
The nervous co-ordinating system
Responds the fastest and is brought about by impulses travelling along nerves
The Endocrine co-ordinating system
Is slower and is brought about by chemicals called hormones which are carried in the blood
