The document provides an introduction to the nervous system. It discusses that the nervous system acts as the main controlling system of the body through quick electrical signals. It has two main subdivisions - the central nervous system comprising the brain and spinal cord, and the peripheral nervous system comprising nerves that connect to organs. The nervous system receives sensory information, integrates it with stored information, and sends out signals through muscles and glands to produce organized responses and secretions while providing conscious experience.
introduction to Autonomic Nervous System consisting of Cholinergic, adrenergic and enteric Nervous system with focus on location of neurotransmitters and broad functions of parasympathetic and sympathetic nervous system.
introduction to Autonomic Nervous System consisting of Cholinergic, adrenergic and enteric Nervous system with focus on location of neurotransmitters and broad functions of parasympathetic and sympathetic nervous system.
1 GNM anatomy Unit -11 Central Nervous System CNS.pptxthiru murugan
By:M. Thiru murugan
Unit – 11:
Types of nerves- structure and functions
Brain and cranial nerves.
Spinal cord and motor and sensory pathways of the spinal cord, autonomic nervous system.
Nervous system:
Nervous system is one of vital system in our body which control and coordinate all the functions of body parts.
Classification:
Central nervous system (CNS)
Peripheral nervous system (PNS)
1. Central nervous system (CNS): brain and spinal cord
2. Peripheral nervous system (PNS): Somatic nervous System & Autonomic nervous system (ANS)
Central Nervous System (CNS):
The central nervous system (CNS) controls most functions of the body and mind.
It consists of two parts: the brain and the spinal cord.
The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement.
It interprets information from our special senses, as well as from internal organs
Meninges:
The coverings of brain and spinal cord are called meninge.
There are 3 layers surrounding the brain and spinal cord.
Dura (outer layer)
Arachnoid (middle layer)
Pia matter (inner layer)
Dura mater: The tough outer layer is called the dura mater. protect the central nervous system.
Arachnoid: The middle layer is the arachnoid, It contains cerebrospinal fluid, which acts to cushion the brain
Pia matter: the innermost layer of the meninges, the pia mater closely covers the brain.
Brain:
Introduction:
The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body.
the brain and spinal cord Together make up the central nervous system, or CNS
The brain receives information through our five senses: sight, smell, touch, taste, and hearing - often many at one time
Diagram:
Structure:
The brain is composed of the cerebrum, cerebellum, and brainstem
Cerebrum (telencephalon or endbrain): is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
Cerebellum (little brain): is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.
Brainstem: consist midbrain, the pons, and the medulla oblongata acts as a relay center connecting the cerebrum and cerebellum to the spinal cord.
Functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.
Lobes of the brain:
Each hemisphere has 4 lobes:
Frontal lobe
Temporal lobe
Parietal lobe
Occipital lobe
Each lobe may be divided, once again, into areas that serve very specific functions
The cerebral cortex has many folds, called the gyrus (plural: "gyri") and its trough is called a sulcus (plural: sulci)
Deep structure of Brain:
Hypothalamus: is located in the floor of the third ventricle and
The Autonomic nervous system divided into two parts i.e sympathetic nervous system and parasympathetic nervous system.
ANS also consists cranial nerve and spinal nerve.
THE NEUROLOGICAL SYSTEM : CEREBROVASCULAR DISORDERSSeraGold
An overview of cerebrovascular disorders is given in this file, which includes ailments including aneurysms, strokes, and vascular abnormalities that affect the blood arteries in the brain. With a focus on causes, symptoms, diagnosis techniques, and treatment options, it provides a thorough overview of these important neurological diseases.
“The right half of the brain controls the left half of the body. This means that only left handed people are in their right mind.”
Made up of brain and spinal cordActs as body’s control center, coordinates body’s activitiesImpulses travel through the neurons in your body to reach the brainCentral Nervous System is yellow in this diagram.
Made up of all the nerves that carry messages to and from the central nervous system.Similar to telephone wires that connect all of our houses in the communityCentral Nervous System and Peripheral Nervous System work together to make rapid changes in your body in response to stimuli.Peripheral Nervous System is green in this diagram.
Somatic Nervous SystemRelay information between skin, skeletal muscles and central nervous systemYou consciously control this pathway by deciding whether or not to move muscles (except reflexes)Reflexes: Automatic response to stimulusAutonomic Nervous SystemRelay information from central nervous system to organsInvoluntary: You do not consciously control theseSympathetic Nervous System: controls in times of stress, such as the flight or fight responseParasympathetic Nervous System: controls body in times of rest
1. Introduction to the
Nervous System
Prof. Vajira Weerasinghe
Professor in Neurophysiology
Faculty of Medicine
University of Peradeniya
(This lecture is available at www.slideshare.net/vajira54)
2.
3. Why study nervous system?
Neurological diseases are disabling
and debilitating and very little treatment
is available
5. Why study nervous system?
Activities such as walking and running and
various forms of exercise and sports require
proper functioning of the nervous system
6.
7. Controlling system
Nervous system is the main
controlling system of the body
Quick
Electrical
Endocrine system also
controls body functions
Slow
Chemical
8. Nerve impulses
• It controls other organs by sending electrical
messages called nerve impulses
It is also the main communication system (like
9. What does it do ?
Functions of the nervous system
1. Receives sensory messages from the external environment
2. Organizes information and integrates it with already stored
information
3. Uses integrated information to send out messages to muscles
and glands, producing organized movement and secretions
4. Provides the basis for conscious experience
11. Anatomical Subdivisions
• Central Nervous system
Brain and spinal cord
• Peripheral Nervous system
Cranial Nerves & Peripheral Nerves
• Autonomic system
sympathetic & parasympathetic
12. Brain - Lobes
• Brain contains the main controlling
centres
• Frontal lobe
Located in the front
Performs motor functions
• Parietal lobe
Located laterally
Performs main sensory functions
13. Brain - Lobes
• Occipital lobe
Located in the back
Performs visual functions
• Temporal lobe
Located laterally
Performs hearing functions
14. Spinal cord
• Functions
To transmit impulses to and from the
brain to the periphery
To cause reflex action
To process information
15. Peripheral nervous system
• Cranial nerves
There are 12 cranial nerves which
connects brain & brainstem with
different organs of the head and neck
region
• Spinal nerves
There are several pairs connecting
different segments of the spinal cord
with peripheral organs
18. Brain stem
• This is an important part of the
nervous system that connects
brain with the spinal cord
• Many cranial nerves arise from
brain stem
• It also contain vital centres
Cardiac, respiratory functions,
consciousness
19. Brain stem
• It has three areas
Midbrain
Pons
(or pons Varoli)
Medulla
(or medulla oblongata)
20. Cerebellum
• This is hind brain
• This is connected to the
brainstem
• Main function is motor
coordination
• Abnormalities result in difficulty
21. Sensory functions
• Functions that make us feel the
environment
• Nerve signals come from the
sensory organ towards the CNS
Afferent signals
• There are different types of
sensory modalities human nervous
system could feel
22. General and special sensations
• There are two main types of sensations
General sensations
Special sensations
23. General sensations
• Mechanical sensations
Touch
Pressure
Vibrations
Stretch
• Thermal sensations
Hot, cold
• Chemical sensation
24. Somatic and visceral sensations
• Somatic sensations
External stimuli sensed by the skin
eg. Feeling of hot environment
• Visceral sensations
Internal sensations sensed by the
visceral afferent nerves
eg. acidity in stomach
26. Proprioception
• Joint and position sensation
• Muscles and tendons contain
receptors which could feel
Muscle length
Joint angle
Position of bones and joint
• This is very important feedback
information for movements of
muscles
27. Motor functions
• Movements are of two
types
Voluntary movements
Consciously controlled
movements
Well thought and planned
Involuntary movements
Reflex action
Control of posture
Balance
28. Voluntary movements
• Planning starts from the brain (frontal
lobe)
• Modified by various intermediate
structures
Brainstem
Cerebellum
• Executed by the brainstem and spinal
cord (lower motor neuron)
29. Reflexes
• Response to a stimulus
• This is an involuntary action
eg. Hot object touching the hand
will cause it to withdraw
• This is called withdrawal reflex
30. What is a reflex?
Stimulus
Effector organ
Response
Central
connections
Efferent nerve
Afferent nerveReceptor
Central control
31. Reflexes
• Reflexes involve many systems of the body
• eg.
Withdrawal reflex (pain and motor pathways)
Pupillary reflex (eye)
Salivatory reflex (salivary glands)
Swallowing reflex (GIT)
Micturition reflex (urinary system)
Baroreceptor reflex (blood pressure control)
Stretch reflex (main reflex in the motor system)
33. Sympathetic system
• This is involved in fight or flight
reaction
• What happens when somebody is
excited
Blood pressure increases
Heart rate increases
Respiratory rate increases
Increased sweating
Pupillary dilatation
GIT function suppressed
34. Parasympathetic system
• This is involved when somebody s
resting
• Blood pressure decreases
• Heart rate decreases
• Respiratory rate decreases
• Decreased sweating
• Pupillary constriction
• GIT function increased
35. Higher functions
• Brain is involved in controlling
higher functions
• Learning
• Memory
• Intelligence
• They are called cognitive functions
36. Basic cell in the nervous system is
is a neuron
Nerve signals are electrochemical impulses
called “action potentials”