Nervous System Samantha Mauricio Pd2 (Cranial Nerves (abducens nerve (VI),…
Nervous System Samantha Mauricio Pd2
Major functions of the
There are sensory neurons which carry information to the CNS and motor neurons which carry information from the CNS
To process and interpret the sensory input.
To respond appropriately to the sensory input.
To collect sensory input from the body and external environment.
Major divisions and subdivisions of the nervous system
Major: Central Nervous System
Consists of the brain and spinal cord Function: transmission, integration, interpretation, memory, cognition
Major: Peripheral Nervous System
Consists of nerves located outside the central nervous system Function: sensory (sensation), motor (movement)
Sensory (afferent) Division
Somatic Sensory: Touch,pain,pressure,vibration,temperaure, and proprioception in skin, body walls , and limbs
Visceral Sensory: Stretch, pain, temperature, chemical ,changes and irritation in viscera; nausea and hunger
Motor (efferent) Division
Somatic Nervous System: Motor innervation of all skeletal muscles
Autonomic nervous system (ANS)
Controls the body's responses to a perceived threat and is responsible for the "fight or flight" response.
controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function
Major part of the brain and
Function: plays an important role in brain function, particularly in coordination and in movement.
Function: controls the flow of messages between the brain and the rest of the body, and it also controls basic body functions
Function: serves as a message station between several areas of the brain
Function: helps regulate breathing, heart and blood vessel function, digestion, sneezing, and swallowing.
Important functions in motor movement, particularly movements of the eye, and in auditory and visual processing.
Function:It connects a large part of the peripheral nervous system to the brain and information (nerve impulses) reaching the spinal cord through sensory neurons are transmitted up into the brain.
Function: to process information to and from the spinal cord and the cerebellum
Function:the largest part of the human brain, associated with higher brain function such as thought and action.
Function: Hearing, learning and feelings
Function: Language and touch
Function: thinking,memory, behavior and movement
With functions linked to speech production.
responsible for the comprehension of speech
the Layers of the Meninges (The 3 Layers of Covering )
D:Delicate web-like layer of the meninges; middle layer
F:It is a very thin sheet of delicate connective tissue that follows the brain's contours
D:the delicate innermost membrane enveloping the brain and spinal cord.
F:it is a moderately tough membrane of connective tissues that cling to the brain's surface
D:Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord
Function:A tough double layer of tissue that encloses the brain and spinal cord in kind of a loose sack
Ventricles:cavities within brain, filled with cerebral spinal fluid
D:A cavity within a cerebral hemisphere that communicates with the lateral ventricle in the other cerebral hemisphere and with the third ventricle by way of the interventricular foramen :
D:A slitlike between the right and left halves of the thalamus and between the lateral ventricles of the brain
D:A cavity filled with cerebrospinal fluid within the brain lying between the cerebellum and the medulla oblongata and pons
Classification of neurons
Classification by Location
Respond to stimuli arising in internal viscera and blood vessels and is sensitive to chemical changes, tissue stretch, and temperature changes
Respond to stimuli arising outside body and receptors in skin for touch, pressure, pain, and temperature
Respond to stretch in skeletal muscles, tendons, joints, ligaments,and connective tissue coverings of bones and muscles
Classification by Receptor Structure
Simple receptors of the general senses
Modified dendritic endings of sensory neurons and are found throughout the body and monitor types of general sensory
Receptors for special senses
Vision, hearing, equilibrium, smell, and taste and All are housed in complex sense organs
Classification by Stimulus Type
Sensitive to changes in temperature
Respond to light energy and an example (retina)
Respond to chemicals and examples (smell,taste, changes in blood chemistry
Sensitive to pain-causing stimuli and examples are (extreme hot or cold,excessive pressure, inflammatory chemicals)
Respond to touch, pressure, vibration and stretch
Diseases associated with the brain
D: a progressive degenerative disease of the brain, ultimately results in dementia (mental deterioration).
D:it is a disorder that results from a degeneration of the dopamine-releasing neurons of the substantia nigra.
D: a fatal hereditary disorder, strikes during middle age. Mutant huntingtin protein accumulates in brain cells and the tissue dies, leading to massive degeneration of the basal nuclei and later of the cerebral cortex.
D: Any disease or disorder of the brain.
D: a class of severe mental illness in which affected individuals lose touch with reality and exhibit bizarre behaviors
D: Is a condition where the patient sleeps more than 15 hour daily
Steps of Action potential
Step 3 Repolarization: Na+ channels close and K+ channels open. K+ rush out of the cell according to the dictates of diffusion. Potential difference: slightly below -85 mV.
Step 2 Depolarization: Sodium channels open in response to a stimulus. Na+ rush into the cell according to the dictates of diffusion. Final potential difference +30 mV.
Step 1 Resting Potential: Sodium and potassium channels are closed. Na+ rush into the cell; K+ are concentrated inside the cell. Potential difference: -85 mV.
Step 4 Hyperpolarization : Na+ and K+ channels are closed. Sodium-potassium exchange pump moves Na+ out and K+ in. Resting potential difference: -85 mV.
Drugs that affect the brain
It slows down movement, which makes us feel calm and relaxed. It also involves unnecessary short term memory lose.
It is highly addictive because it works directly on the brain's reward pathway and makers the user feel intense pleasure and exhilaration.
It affects serotonin pathways responsible for mood, sleep, perception, and appetite.
It affects memory formation, decision making and impulse control (areas from the brain).
It produces feelings of sedation and well-being.
It concentrales in the reward pathway and voluntary movement. The reason why abusers are fidgety and unable to stay still
It affects the feeling for wakefulness and evoking a startle response to unexpected stimulus.
Major nerves of the body
D: a network of nerves formed by the ventral rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1).
D: a large superficial nerve of the arm that is a continuation of the medial cord of the brachial plexus, passes around the elbow superficially in a groove between the olecranon
D: a nerve in the human body that supplies the posterior portion of the upper limb and it innervates the medial and lateral heads of the triceps brachii muscle of the arm,
D: the smaller of the branches into which the sciatic nerve divides passing obliquely outward and downward from the popliteal space and to the neck of the fibula where it divides into the deep peroneal nerve and the superficial peroneal nerve that supply certain muscles and skin areas of the leg and foot.
D:the large nerve in the back of the leg that is a continuation of the sciatic nerve and terminates at the medial malleolus in the lateral and medial plantar nerves.
D: It is the largest branch of the lumbar plexus that in humans comes from the second, third, and fourth lumbar nerves and supplies extensor muscles of the thigh and skin areas on the front of the thigh and medial surface of the leg and foot and that sends articular branches to the hip and knee joints.
D: a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis.
D: It begins from nerve roots in the lumbar part of the spinal cord (in the low back) and extends through the buttock area to send nerve endings down to the legs
D: are the somatic nerves that arise from the anterior divisions of the thoracic spinal nerves from T1 to T11. These nerves in addition to supplying the thoracic wall also supply the pleura and peritoneum.
D: a web of nerves (a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. It is formed by the divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last thoracic nerve
hypoglossal nerve (XII)
trochlear nerve (IV)
oculomotor nerve (III)
the optic nerve (II)
trigeminal nerve (V)
Olfactory nerves (I)
abducens nerve (VI)
facial nerve (VII)
vestibulocochlear nerve (VIII)
glossopharyngeal nerve (IX)
vagus nerve (X)
accessory nerve (XI)
5 pairs of lumbar nerves (L1-L5)
5 pairs of sacral nerves (S1-S5)
12 pairs of thoracic nerves (T1 – T12)
1 pair of coccygeal nerves (Co1)
8 pairs of cervical nerves (C1-C8)
Anatomy of the spinal cord
Located inside the vertebral canal, which is formed by the foramina of 7 cervical, 12 thoracic, 5 lumbar, and 5 sacral vertebrae, which together form the spine. ... 5 sacral (S) segments. 1 coccygeal (Co) segment - mainly vestigial.
Types of Neurotransmitters
D: Major excitatory neurotransmitter involved in information transmission throughout the brain
GABA (gamma-aminobutyric acid)
D: the primary inhibitory neurotransmitter in the brain
D: regulates motor behavior, motivation, pleasure, and emotional arousal; plays a role in drug addiction;
D: Influences mood and arousal; involved in states of heightened awareness when there is danger
D:Involved in regulation of sleep and wakefulness, eating, and aggressive behaviour
D:involved in voluntary motor control; found in synapses where axons connect to muscles and body organs; contributes to regulation of attention, learning, sleeping, dreaming, and memory
D:Chemicals that act within pain pathways and emotion centers of the brain; dulls experience of pain, release causes "runner's high"
Parts of a Reflex Arc
motor neuron- the efferent neuron that transmits the response to the effector organ or gland
interneuron- small neuron within the spinal cord that connects the sensory neuron to the motor neuron
sensory neuron- afferent neuron that transmits the impulse to the spinal cord
receptor- sensory cell that is stimulated
effector organ- the muscle or the gland that performs the appropriate response