Nervous system
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The document provides an extensive overview of the human nervous system, detailing its anatomy, including the brain's structure and function, neurotransmitters, and the autonomic nervous system's divisions. It highlights the roles of different brain regions, such as the cerebral cortex, limbic system, and various neuronal classes and their functions. Additionally, it outlines the impact of neurotransmitter levels on mental health and describes how the nervous system operates both in relaxation and stress.
Nervous system
- 1. Nervous System Susmita Halder M.Sc. Nursing 1st Year Govt . College of Nursing, Bankura Sammilani Medical College & Hospital
- 2. An anatomical review Brain & Limbic system CONTENTS Nerve Tissue Neurotransmitters Autonomic nervous system
- 6. The Brain The adult human brain weighs on average about 1.2–1.4 kg (2.6–3.1 lb) which is about 2% of the total body weight, with a volume of around 1260 cm3 in men and 1130 cm3 in women. There is substantial individual variation, with the standard reference range for men being 1,180–1,620 g (2.60–3.57 lb) and for women 1,030–1,400 g (2.27–3.09 lb)
- 7. Parts of Brain FORE BRAIN HIND BRAIN MID- BRAIN
- 8. Parts of Brain The brain has major three divisions which are subdivided into six major parts. 1. Forebrain- a. Cerebrum b. Diencephalon 2. Mid brain- a. Mesencephalon 3. Hind brain- a. Pons b. Medulla oblongata c. Cerebellum
- 9. MAJOR PARTS OF BRAIN CEREBRUM DIENCEPHALON MESCENCEPHALON PONS CEREBELLUM MEDULLA OBLANGATA
- 10. The Brain 1. FORE BRAIN i. Cerebrum: Composed of two cerebral hemispheres connected by a deep groove which houses a band of 200 million neurons called the corpus callosum. • The surface of cerebrum consists of grey matter, known as cerebral cortex. • Another pair of masses of grey matter is called basal ganglia. It is found deep within the cerebral hemispheres, are responsible for certain subconcious aspects of voluntary movement such as swinging the arms, when walking, gesturing while speaking and regulating muscle tone
- 12. CONT.. The cerebral cortex is identified by numerous folds called gyri, and the deep grooves between the folds are known as sulci. • Left hemisphere appears to deal with logic and problem solving, controls speech comprehension rationally. • Right hemisphere is associated with affect, behaviour, and spatial perceptual function.
- 13. Activities Right Hemisphere Left hemisphere Specialities • Copying of designs • Discrimination of shapes • Reading • Music • Holistic processing • Understanding metaphor • Expressing emotions • Language skills • Skilled movements Emotions • Negative Emotions • Positive Emotions Neurotransmitters • Higher Levels of norepinephrine • Higher levels of dopamine Grey matter and white matter ratio • More white matter on right • More Grey matter on the left Shared • Sensations on both side of the face • Sound perceived by both ears • Pain • Hunger • Position
- 16. Cortical areas and its functions Cortical area Function Primary motor cortex Initiation of voluntary movement Primary somatosensory cortex Receives tactile information pain pressure position movement and temperature Motor association cortex Coordination of complex movements Speech centre broca’s area Speech Production and articulation Auditory cortex Auditory perception and healing Auditory association area Complex processing of auditory information Sensory association area Complex processing of multisensory information Visual association area Primary visual perception Wenicke’s area Spoken language Comprehension
- 18. Cont.. • Each cerebral hemisphere consists of four lobes. • FRONTAL LOBE- Controls body movements, formation of speaking, thinking and judgement. It has a role in emotional experiences and expression of mood. • PARIETAL LOBE- Controls perception and interpretation of sensory information. Touch, taste, pain, body position, language interpretation, is asscociated with left hemisphere of parietal lobe.
- 19. Frontal Lobe • Voluntary body movement • Including movements that permit- • speaking • Thinking • judgement formation, • expression of feelings
- 20. Parietal lobe • Perception and interpretation of most sensory information includes- • Touch • Pain • Taste • Body position
- 21. • TEMPORAL LOBE- Auditory functions are performed by upper snterior lobe. Lowe lobe performs the function of short term memory. It involves in complex aspets of memory and learning, functions of abstract thought and judgement. It has a role of smell, expression of emotions through limbic system connectivity. Left temporal lobe helps in language interpretation. • OCCIPITAL LOBE- It has primary areas of visual perception and interpretation language perception through an association with visual experiences.
- 22. Temporal Lobe • Hearing • Short-term memory • Sense of smell • Expression of emotions through connection with limbic system
- 23. Occipital Lobe • Visual reception • Interpretation
- 25. cont.. ii. Diencephalon- Connects the cerebrum with lower structures of the brain. • Thalamus is a critical structure containing the consciousness. Thalamus integrats all sensory inputs except smeel. It is involved with emotions and moodsuch as fear and rage.
- 26. Diencephalon • Connects cerebrum with lower brain structures
- 27. Thalamus • Integrates all sensory input (except smell) on way to cortex • Involvement with emotions and mood
- 28. cont.. • Hypothalamus is located just below the thalamus and just above the pituitary gland, and has a number of diverse functions.
- 29. Hypothalamus • Regulates anterior and posterior lobes of pituitary gland • Exerts control over actions of the ANS • Regulates appetite and temperature.
- 30. Hypothalamus is located just below the thalamus and just above the pituitary gland, and has a number of diverse functions. 3 2 1 6 7 8 4 5 9 REGULATION OF APPETITE POST. PITUITARY STORES OXYTOCIN, STIMULATES UTERUS, SECRETS MILK REGULATION OF TEMPRETURE ACTS A VITAL ROLE DIRECT NEURAL CONTROL OVER ANS ACT AS ‘RELEASING FACTORS’ POST. PITUITARY STORES ADH AND CONTROLS BP REGULATION OF PITUITARY GLAND FUNCTIONS
- 31. Limbic System- Part of brain known as limbic system consists of portions of cerebrum and diencephalon. the major components include medially placed cortical and subcortical structures and the fibres connecting with each other and with the hypothalamus which is is composed of • 1. Hippocampus • 2. Mammillary body • 3. Amygdala • 4. Olfactory Tract • 5. Hypothalamus • 6. Cirgulate gyrus • 7. Septem pellucidum • 8. Fornix
- 32. Limbic System • Known as “Emotional Brain “ • Feelings of fear & anxiety • Anger & aggression • Love, joy • Sexuality • Social Behavior
- 33. MID BRAIN Structures of mid brain include nuclei and fiber tracts. It extends fro pons to hypothalamus. It is responsible for integration of various reflexes including visual reflexes auditory reflexes and righting reflexes (automatically keeping the head upright and maintaining the balance)
- 34. Mid brain • Visual • Auditory • Balance reflexes
- 36. C. Hind Brain • i. Pons is a bulbous structure that lies between the mid brain and the medulla. It is composed of large bundles of fibres forms a connection between the cerebellum and the brain stem. • It also contains the central connections of cranial nerves V through VIII centres for respiration and skeletal muscle tone
- 37. Pons • Regulation of respiration • Skeletal muscle tone • Ascending and descending tracts connects brain stem with cerebellum and cortex
- 38. CONT.. • ii. Medulla is the connecting structure between the spinal cord and the pons. All of the ascending and descending fibres pass through it. the medulla pons and meet brain from the structure and known as brainstem • It contains vital centres that regulate heart rate blood pressure respiration reflex centres for swallowing sneezing coughing and vomiting. Also contains nuclei for cranial nerves IX through XII
- 39. Medulla • Regulates heart rate & BP • Respiration • Reflex centre for sneezing, swallowing, coughing and vomiting
- 40. CONT.. • iii. Cerebellum is separated from brain by fourth ventricle but has connections to the brainstem through the bundles of fibre tracts. It is situated just below the occipital lobes of the cerebrum • It is concerned with involuntary movements such as muscular tone coordination and maintenance of posture and equilibrium.
- 41. Cerebellum • Regulates muscle tone • Coordination • Maintains posture and equilibrium
- 42. BASAL GANGLIA • 2. Basal ganglia grey matters that are functionally related and located bilaterally in cerebrum, diencephalon and midbrain • It controls muscle tone and movement dysfunction which leads to Parkinson's disease
- 43. Nerve Tissue
- 44. Parts of Neuron NEURON The tissue of central nervous system consists of nerve cells are called neurones CELL BODY Contains the nucleus AXONS Transmit impulses away from the body. DENDRITES Transmit impulses towards the cell body
- 46. CLASSES OF NEURONES SENSORY NEURONES INTER NEURONES MOTOR NEURONES Carries impulses from the receptors in the internal external pathway to central nervous system Carries impulses from the central nervous system effectors in the periphery and in the muscles Inter neurones exist in tally within the central nervous system which carry only sensory or motor impulses play as integrators in the pathway between afferent and efferent neurones.
- 52. Neurotransmitters CHOLINERGICS • Acetylcholine MONOAMINES • Norepinephrine • Dopamine • Serotonin • Histamine AMINO ACIDS • GABA • Glycine • Glutamate & Aspertate • D- Serine NEUROPEPTIDES • Endorphins and enkephalins • Substance P • Somatostatin
- 53. Neurotransmitters Function When decreased When increased 1. CHOLINERGICS Acetylcholine 1. Sleep, arousal, pain perception, movement, memory Aljheimer’s disease Depression 2. MONOAMINES a. Norepinephrine Mood cognition perception locomotion cardiovascular functioning sleep and arousal Depression Mania anxiety States Schizophrenia b. Dopamine Movement and coordination emotions voluntary judgement release of prolactin Parkinson’s disease and depression Mania and schizophrenia c. Serotonin Sleep arousal libido apatite Mood aggression Pain perception coordination judgement Depression Anxiety States d. Histamine Control of gastric secretions smooth muscle control cardiac stimulation stimulation of sensory nerve endings and alertness Depression
- 54. Neurotransmitters Function When decreased When increased 3. AMINO ACIDS a. GABA Slow down of body activity Anxiety disorders schizophrenia and various forms of epilepsy b. Glycine Recurrent inhibition of motor neurons Correlated with spastic motor movements Glycine encephalopathy. . Glutamate and Aspartate Relay of sensory information and in regulation of various motor and spinal reflexes Huntington’s disease temporal lobe epilepsy spinal cerebellar degeneration d. D- Serine Binds at NMDA receptors, with glutamate, is a co-agonist who functions include mediating NMDA receptor transmission, synaptic plasticity, neurotoxicity Schizophrenia
- 55. Neurotransmitters Function When decreased When increased 4. NEUROPEPTIDES a. Endorphins and Enkephalins Modulation of pain and reduced peristalsis Modulation of dopamine activity by opioid peptides. May indicate some lead to the symptoms of schizophrenia. b. Substance P Regulation of pain Huntington’s disease and Alzheimer’s disease Depression c. Somatostatin Inhibits release of norepinephrine stimulates the release of serotonin dopamine and acetylcholine Alzheimer’s disease Huntington’s disease
- 56. NEUROTRANSMITTERS & RELATED MENTAL DISORDERS Decrease in glutamate level Decrease in gamma- aminobutyric acid level Increase in dopamine level Decrease in norepinephrine level Decrease in serotonin level Psychotic thinking Anxiety Schizophrenia Depression Alzheimer’s disease
- 60. AUTONOMIC NERVOUS SYSTEM Sympathetic Division Parasympathetic Division Neuronal bodies of parasympathetic division originate in the brainstem and the sacral segments of spinal cord and extend to the parasympathetic ganglia where the synapse takes place either very close or actually in the visceral organ being innervated. The parasympathetic division dominates when the individual is in relaxed non stressful condition. The heart rate and respiration and maintained in normal rate and secretions and peristalsis increase for normal digestion. Elimination functions are promoted. Neuronal bodies of sympathetic division originate in the thoracolumbar region of the spinal cord. The their axons Austin to the chains of sympathetic ganglia where they synapse with other neurones that subsequently innovate the visceral effectors resulting in increased heart rate and respirations and a decrease in digestive secretions and peristalsis. Blood is shunted to the vital organs and skeletal muscles to ensure adequate oxygenation
- 61. SUMMMERIZATION NERVOUS SYSTEM Nervous system is com various complex structures which are essential to understand psychobiology that will enhance knowledge BRAIN LIMBIC SYSTEM NERVE TISSUES CNS ANS NEURO TRANSMI TTERS
- 63. THANK YOU