Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.
FUNCTIONS OF THE NERVOUS SYSTEMFUNCTIONS OF THE NERVOUS SYSTEM
• Sensory input – Gathering information. To
monitor changes...
CLASSIFICATIONCLASSIFICATION OF THE NERVOUSOF THE NERVOUS
SYSTEMSYSTEM
• Central nervous
system (CNS):
•Brain
•Spinal cord...
THE PERIPHERAL NERVOUS SYSTEMTHE PERIPHERAL NERVOUS SYSTEM
• Sensory (afferent) division - Nerve
fibers that carry informa...
AUTONOMIC NERVOUSAUTONOMIC NERVOUS
SYSTEMSYSTEMAutonomic nervous system is considered as a self-control
system that comes ...
ENTERIC NERVOUS SYSTEM (ENS)ENTERIC NERVOUS SYSTEM (ENS)
The ENS is also called second brain in the wall of the
gut. The t...
CLASSIFICATION OF NERVOUS SYSTEMCLASSIFICATION OF NERVOUS SYSTEM
NERVOUS SYSTEM HISTOLOGYNERVOUS SYSTEM HISTOLOGY
Neurons = nerve cells
• Cells specialized to transmit electrochemical mes...
GLIAGLIA
Two main types of cells in nervous system
1.Neurons: they are excitable cells that conduct impulses to
make all n...
GLIAGLIA
Astrocytes: Star shaped cells found in CNS. Largest glia
cells. They feed neurons with lactic acid made from gluc...
Axon of another
neuron
Axon of another
neuron
Cell BodyCell BodyDendritesDendrites
AxonAxon
Myelin
Sheath
Myelin
Sheath
De...
CHARACTERSETICS OF NEURON:CHARACTERSETICS OF NEURON:
•NEURONS ARE LIKE OTHER BODY CELLSNEURONS ARE LIKE OTHER BODY CELLS
•...
STRUCTURE OF NEURONSTRUCTURE OF NEURON
• A DENDRITE IS A STRUCTURE OF THE NEURON THATA DENDRITE IS A STRUCTURE OF THE NEUR...
NEURON ANATOMYNEURON ANATOMY
• Dendrites – conduct impulses
toward the cell body
• Telo-dendria: the distal tip
axon that ...
AXONS.AXONS.
• IF AN AXON HAS MYELIN, THE INFORMATION ITIF AN AXON HAS MYELIN, THE INFORMATION IT
SENDS CAN TRAVEL FASTER ...
Types of Neurons
Sensory Motor Interneurons
MOTOR NEURONMOTOR NEURON
SENSORY NEURONSENSORY NEURON
NEURONSNEURONS
Figure 7.6
NEURON FUNCTIONNEURON FUNCTION
ELECTRICAL NATURE OF NEURONSELECTRICAL NATURE OF NEURONS
ELECTRICAL NATURE OF NEURONSELECTRICAL NATURE OF NEURONS
• When a stimulus is applied to a neuron the stimulus
gated Na+ channel open. Na+ diffuse rapidly into the
cell because of...
• Voltage gated channels stay open for only about 1
milliseconds before they automatically closes. It is automatic
and hap...
REFRACTORY PERIODREFRACTORY PERIOD
CONDUCTION OF THE ACTIONCONDUCTION OF THE ACTION
POTENTIALPOTENTIAL
CONDUCTION OF THE ACTIONCONDUCTION OF THE ACTION
POTENTIALPOTENTIAL
SYNAPTIC TRANSMISSIONSYNAPTIC TRANSMISSION
TYPES OF SYNAPSETYPES OF SYNAPSE
TYPES CONTD….TYPES CONTD….
Multiple ways of
connecting
1.Axon to Dendrite –
excite or inhibit neuron
2.Axon to Axon Termin...
MECHANISM OF SYNAPTICMECHANISM OF SYNAPTIC
TRANSMISSIONTRANSMISSION
MECHANISM OF SYNAPTICMECHANISM OF SYNAPTIC
TRANSMISSIONTRANSMISSION
SYNAPSE FUNCTIONSYNAPSE FUNCTION
SYNAPSES AND MEMORYSYNAPSES AND MEMORY
NEUROTRANSMITTER TYPESNEUROTRANSMITTER TYPES
NEUROTRANSMITTER TYPESNEUROTRANSMITTER TYPES
Figure 9-4b
Figure 9-4b
Figure 9-4b
Figure 9-4b
Figure 9-6: The blood-brain barrier
Figure 9-6: The blood-brain barrier
http://www.driesen.com/diencephalon.htm
Figure 9.8
neuroscienceMizanneuroscienceMizan
neuroscienceMizanneuroscienceMizan
LUMBAR PLEXUSLUMBAR PLEXUS
SACRAL PLEXUS & COCCYGEAL PLEXUSESSACRAL PLEXUS & COCCYGEAL PLEXUSES
 Component: Sensory
 Function: Smell
 Opening to the Skull: Openings in
cribriform plate of Ethmoid (facial
bone)
 Ori...
 Component: Sensory
 Function: Vision
 Opening to the Skull: Optic
Canal/foramina
 Origin: Back of the eyeball
 Component: Motor
 Function:
 Raises upper eyelid
 Turns eyeball upward, downward and
medially
 Constricts pupil
 Ac...
 Component: Motor
 Function: Assisting in turning eyeball
downward and laterally
 Opening to the Skull: Superior orbita...
 Component: Sensory
 Function:
 Cornea
 Skin of forehead
 Scalp
 Eyelids and nose
 Mucous membranes of paranasal
si...
o Component: Sensory
o Function:
o Skin of the face over maxilla
o Teeth of the upper jaw
o Mucous membrane of the nose, t...
o Component: a. Motor
o Function:
o Muscles of mastication
o Mylo-hyoid: muscle from mandible to hyoid
forming the floor o...
• Component: b. Sensory
• Function:
• Skin of cheek
• Skin over mandible and side of head
• Teeth of lower jaw and TMJ
• M...
 Component: Motor
 Function: Lateral rectus muscle turns eyeball
laterally
 Opening to the Skull: Superior orbital fiss...
Feature Somatic Motor
Pathways
Autonomic Pathways
Direction of flow Efferent Efferent
No. of neurons
between CNS
and effec...
Hydrocephalus
FLEXOR (WITHDRAWL) REFLEXFLEXOR (WITHDRAWL) REFLEX
IT IS A SPINAL REFLEX, AT
THE TIME OF INJURY. THIS
PULLS AWAY FROM THE
...
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Johny's Anatomy & Physiology Part 2
Nächste SlideShare
Wird geladen in …5
×

Johny's Anatomy & Physiology Part 2

1.926 Aufrufe

Veröffentlicht am

Anatomy and Physiology of Nervous System

Veröffentlicht in: Gesundheitswesen
  • Als Erste(r) kommentieren

Johny's Anatomy & Physiology Part 2

  1. 1. FUNCTIONS OF THE NERVOUS SYSTEMFUNCTIONS OF THE NERVOUS SYSTEM • Sensory input – Gathering information. To monitor changes occurring inside and outside the body. • Integration - To process and interpret sensory input and decide if action is needed. • Motor output. A response to stimuli and Activates muscles or glands. • The nervous system maintains the homeostasis of the body. • Nervous system is a large network of interconnected systems.
  2. 2. CLASSIFICATIONCLASSIFICATION OF THE NERVOUSOF THE NERVOUS SYSTEMSYSTEM • Central nervous system (CNS): •Brain •Spinal cord • Peripheral nervous system (PNS): •Nerves outside the brain and spinal cord
  3. 3. THE PERIPHERAL NERVOUS SYSTEMTHE PERIPHERAL NERVOUS SYSTEM • Sensory (afferent) division - Nerve fibers that carry information to the central nervous system. • Motor (efferent) division - Nerve fibers that carry impulses away from the central nervous system. • Somatic system: They carry information to somatic effectors which are skeletal muscles. This is a motor pathway. This also include afferent pathways made of somatic sensory division that provide feedback. They are voluntary. • Autonomic system: Involuntary
  4. 4. AUTONOMIC NERVOUSAUTONOMIC NERVOUS SYSTEMSYSTEMAutonomic nervous system is considered as a self-control system that comes under peripheral nervous system. It basically regulates the internal environment of the body, exchanging commands between peripheral nervous system and organs in order to maintain important body functions. There are two divisions in the autonomic nervous system. Sympathetic nervous system “fight or flight” response. The main function of the sympathetic nervous system is to prepare the body for emergency situation and to produce rapid mobilizations to avoid the danger. Parasympathetic nervous system. “housekeeping”. This system is responsible to maintain the activities such as “rest- and – digest” or “feed- and- breed” that occur when body is at rest.
  5. 5. ENTERIC NERVOUS SYSTEM (ENS)ENTERIC NERVOUS SYSTEM (ENS) The ENS is also called second brain in the wall of the gut. The term enteric means intestinal or we call it as intestinal nervous system. It is a part of autonomic nervous system. But it communicates between afferent and efferent pathways. It has its own mind and a network of integrators and feedback loops that act somewhat independently.
  6. 6. CLASSIFICATION OF NERVOUS SYSTEMCLASSIFICATION OF NERVOUS SYSTEM
  7. 7. NERVOUS SYSTEM HISTOLOGYNERVOUS SYSTEM HISTOLOGY Neurons = nerve cells • Cells specialized to transmit electrochemical messages • Major regions of neurons • Cell body – nucleus and metabolic center of the cell • Processes – fibers that extend from the cell body
  8. 8. GLIAGLIA Two main types of cells in nervous system 1.Neurons: they are excitable cells that conduct impulses to make all nervous system make functional. 2.Glia: they do not conduct impulses but sup[port the function of neurons in various ways. a.Neuroglia is derived from glia=glue. b.Found by Camillo Golgi c.Unlike neurons it has the capacity of cell division and it susceptible to cause cancer. d.Glia mainly consists of 5 types of cells such as Astrocytes, Microglia, Ependymal cells, Oligodendrocytes, Schwann cells.
  9. 9. GLIAGLIA Astrocytes: Star shaped cells found in CNS. Largest glia cells. They feed neurons with lactic acid made from glucose picked from blood. Helps in production of neurons and neural connections in the early stage of life. They help to form Blood Brain Barrier in the capillary network of brain to prevent the entry of large molecules such as water, alcohol, CO2 etc. Microglia: Small stationery cells found in CNS. Does phagocytosis. Ependymal cells: Resemble epithelial cells and helps in fluid circulation around cavities. Oligodendrocytes: tiny cells found in cluster. They help in formation of myelin sheath around nerve fibers in CNS. Schwann cells: or neuro-lemmocytes are the glia of the PNS. Glial cells function to support neurons and in the PNS.
  10. 10. Axon of another neuron Axon of another neuron Cell BodyCell BodyDendritesDendrites AxonAxon Myelin Sheath Myelin Sheath Dendrites of another neuron Dendrites of another neuron
  11. 11. CHARACTERSETICS OF NEURON:CHARACTERSETICS OF NEURON: •NEURONS ARE LIKE OTHER BODY CELLSNEURONS ARE LIKE OTHER BODY CELLS • THEY HAVE A CELL MEMBRANE & A NUCLEUS THATTHEY HAVE A CELL MEMBRANE & A NUCLEUS THAT CONTAINS DNACONTAINS DNA • SOME WORKING PARTS OF THE CELL KNOWN ASSOME WORKING PARTS OF THE CELL KNOWN AS ORGANELLES,ORGANELLES, • THEY CARRY ON PROTEIN SYNTHESIS AND ENERGYTHEY CARRY ON PROTEIN SYNTHESIS AND ENERGY PRODUCTION.PRODUCTION. •NEURONS ARE DIFFERENT FROM OTHER BODY CELLS:NEURONS ARE DIFFERENT FROM OTHER BODY CELLS: • THEY HAVE AN IRREGULAR SHAPE & THEY HAVETHEY HAVE AN IRREGULAR SHAPE & THEY HAVE SPECIALIZED EXTENSIONS CALLED DENDRITES ANDSPECIALIZED EXTENSIONS CALLED DENDRITES AND AXONSAXONS • THEY COMMUNICATE WITH EACH OTHER THROUGHTHEY COMMUNICATE WITH EACH OTHER THROUGH THE ELECTROCHEMICAL PROCESSTHE ELECTROCHEMICAL PROCESS • THEY HAVE SOME OTHER SPECIALIZEDTHEY HAVE SOME OTHER SPECIALIZED STRUCTURES (SUCH AS THE SYNAPSE)STRUCTURES (SUCH AS THE SYNAPSE) • THEY USE CHEMICALS FOR COMMUNICATIONTHEY USE CHEMICALS FOR COMMUNICATION CALLED NEUROTRANSMITTERS.CALLED NEUROTRANSMITTERS.
  12. 12. STRUCTURE OF NEURONSTRUCTURE OF NEURON • A DENDRITE IS A STRUCTURE OF THE NEURON THATA DENDRITE IS A STRUCTURE OF THE NEURON THAT BRINGS INFORMATION TO THE CELL BODY FROMBRINGS INFORMATION TO THE CELL BODY FROM ANOTHER NEURON. IT HAS A ROUGH SURFACE, WITHANOTHER NEURON. IT HAS A ROUGH SURFACE, WITH LITTLE BUMPS CALLED DENDRITIC SPINES THATLITTLE BUMPS CALLED DENDRITIC SPINES THAT INCREASE THE SURFACE AREA OF THE DENDRITEINCREASE THE SURFACE AREA OF THE DENDRITE SO IT CAN RECEIVE MORE INFORMATION FROM THESO IT CAN RECEIVE MORE INFORMATION FROM THE NEIGHBORING NEURON. USUALLY THERE ARE MANYNEIGHBORING NEURON. USUALLY THERE ARE MANY DENDRITES ON EACH CELL, AND DENDRITES DON’TDENDRITES ON EACH CELL, AND DENDRITES DON’T HAVE MYELIN AS THE AXON DOES. DENDRITESHAVE MYELIN AS THE AXON DOES. DENDRITES USUALLY BRANCH NEARER TO THE CELL BODY THANUSUALLY BRANCH NEARER TO THE CELL BODY THAN DOES THE AXON.DOES THE AXON. • AN AXON CARRIES INFORMATION AWAY FROM THEAN AXON CARRIES INFORMATION AWAY FROM THE CELL BODY TO THE DENDRITES OF A NEIGHBORINGCELL BODY TO THE DENDRITES OF A NEIGHBORING NEURON OR TO ANOTHER BODY STRUCTURE SUCHNEURON OR TO ANOTHER BODY STRUCTURE SUCH AS A MUSCLE. AXONS HAVE SMOOTH SURFACESAS A MUSCLE. AXONS HAVE SMOOTH SURFACES AND NO SPINES LIKE DENDRITES HAVE. MOSTAND NO SPINES LIKE DENDRITES HAVE. MOST NEURONS HAVE ONLY ONE AXON, AND THE AXONNEURONS HAVE ONLY ONE AXON, AND THE AXON BRANCHES FURTHER FROM THE BODY THAN THEBRANCHES FURTHER FROM THE BODY THAN THE DENDRITE DOES.DENDRITE DOES.
  13. 13. NEURON ANATOMYNEURON ANATOMY • Dendrites – conduct impulses toward the cell body • Telo-dendria: the distal tip axon that end in synaptic nobe. • Cell body (soma): also called perikaryon. It contains organelles & substance (specialized rough ER) • Axons – conduct impulses away from the cell body • Schwann cells – produce myelin sheaths in jelly-roll like fashion • Nodes of Ranvier – gaps in myelin sheath along the axon
  14. 14. AXONS.AXONS. • IF AN AXON HAS MYELIN, THE INFORMATION ITIF AN AXON HAS MYELIN, THE INFORMATION IT SENDS CAN TRAVEL FASTER THAN IF THE AXONSENDS CAN TRAVEL FASTER THAN IF THE AXON DOES NOT HAVE MYELIN.DOES NOT HAVE MYELIN. • MYELIN IS PRODUCED BY SUPPORT CELLS IN THEMYELIN IS PRODUCED BY SUPPORT CELLS IN THE NERVOUS SYSTEM CALLED GLIA. MYELINATIONNERVOUS SYSTEM CALLED GLIA. MYELINATION AFFECTS THE SPEED OF NEURAL TRANSMISSION.AFFECTS THE SPEED OF NEURAL TRANSMISSION. • THERE ARE BREAKS AT VARIOUS POINTS IN THETHERE ARE BREAKS AT VARIOUS POINTS IN THE MYELIN THAT SURROUNDS THE AXON, AND THESEMYELIN THAT SURROUNDS THE AXON, AND THESE BREAKS ARE CALLED NODES OF RANVIER.BREAKS ARE CALLED NODES OF RANVIER. • AS AN ELECTRICAL SIGNAL, CALLED AN ACTIONAS AN ELECTRICAL SIGNAL, CALLED AN ACTION POTENTIAL, TRAVELS DOWN THE AXON, THE ACTIONPOTENTIAL, TRAVELS DOWN THE AXON, THE ACTION POTENTIAL “JUMPS” FROM NODE TO NODE.POTENTIAL “JUMPS” FROM NODE TO NODE. • THIS JUMPING ALLOWS THE SIGNAL TO TRAVELTHIS JUMPING ALLOWS THE SIGNAL TO TRAVEL MUCH FASTER THAN IT WOULD BE ABLE TO IF ITMUCH FASTER THAN IT WOULD BE ABLE TO IF IT HAD TO TRAVEL ALONG AN AXON WITHOUT MYELIN.HAD TO TRAVEL ALONG AN AXON WITHOUT MYELIN. • THIS TYPE OF MOVEMENT BY AN ACTION POTENTIALTHIS TYPE OF MOVEMENT BY AN ACTION POTENTIAL ALONG AN AXON WITH MYELIN IS CALLEDALONG AN AXON WITH MYELIN IS CALLED
  15. 15. Types of Neurons Sensory Motor Interneurons
  16. 16. MOTOR NEURONMOTOR NEURON
  17. 17. SENSORY NEURONSENSORY NEURON
  18. 18. NEURONSNEURONS Figure 7.6
  19. 19. NEURON FUNCTIONNEURON FUNCTION
  20. 20. ELECTRICAL NATURE OF NEURONSELECTRICAL NATURE OF NEURONS
  21. 21. ELECTRICAL NATURE OF NEURONSELECTRICAL NATURE OF NEURONS
  22. 22. • When a stimulus is applied to a neuron the stimulus gated Na+ channel open. Na+ diffuse rapidly into the cell because of the concentration gradient and electrical gradient producing local depolarization. • When the magnitude of the local depolarization surpasses the limit called threshold potential Voltage gated channels of Na+ open. They are ion channels that respond to voltage changes. There are many Na+ and K+ channels in the membrane of the neuron. • As more Na+ rushes into the cell the membrane moves rapidly toward 0mV and then continues in a positive direction to a peak of +30mV. + indicate that there are excess positive ions inside the membrane.
  23. 23. • Voltage gated channels stay open for only about 1 milliseconds before they automatically closes. It is automatic and happens if and only if the threshold potential is surpassed otherwise no action potential created. • Once the peak action potential is reached the membrane potential begins to move back towards resting potential which called repolarization. (-70mV). Surpassing the threshold potential not triggers Na+ channel but also K+ channel. The K+ channel is slow to respond but still it helps in the outflow of the excess positive ions thus repolarizing the membrane. • Since the K+ channel often remain open as the membrane reaches its resting potential, too much K+ ions may rush out thus there is a period of hyperpolarization before the resting potential is restored and K+ channel closes.
  24. 24. REFRACTORY PERIODREFRACTORY PERIOD
  25. 25. CONDUCTION OF THE ACTIONCONDUCTION OF THE ACTION POTENTIALPOTENTIAL
  26. 26. CONDUCTION OF THE ACTIONCONDUCTION OF THE ACTION POTENTIALPOTENTIAL
  27. 27. SYNAPTIC TRANSMISSIONSYNAPTIC TRANSMISSION
  28. 28. TYPES OF SYNAPSETYPES OF SYNAPSE
  29. 29. TYPES CONTD….TYPES CONTD…. Multiple ways of connecting 1.Axon to Dendrite – excite or inhibit neuron 2.Axon to Axon Terminal – moderate NT releases 3.Axon to Extracellular Space or blood – potential for diffuse effects
  30. 30. MECHANISM OF SYNAPTICMECHANISM OF SYNAPTIC TRANSMISSIONTRANSMISSION
  31. 31. MECHANISM OF SYNAPTICMECHANISM OF SYNAPTIC TRANSMISSIONTRANSMISSION
  32. 32. SYNAPSE FUNCTIONSYNAPSE FUNCTION
  33. 33. SYNAPSES AND MEMORYSYNAPSES AND MEMORY
  34. 34. NEUROTRANSMITTER TYPESNEUROTRANSMITTER TYPES
  35. 35. NEUROTRANSMITTER TYPESNEUROTRANSMITTER TYPES
  36. 36. Figure 9-4b
  37. 37. Figure 9-4b
  38. 38. Figure 9-4b
  39. 39. Figure 9-4b
  40. 40. Figure 9-6: The blood-brain barrier
  41. 41. Figure 9-6: The blood-brain barrier
  42. 42. http://www.driesen.com/diencephalon.htm
  43. 43. Figure 9.8
  44. 44. neuroscienceMizanneuroscienceMizan
  45. 45. neuroscienceMizanneuroscienceMizan
  46. 46. LUMBAR PLEXUSLUMBAR PLEXUS
  47. 47. SACRAL PLEXUS & COCCYGEAL PLEXUSESSACRAL PLEXUS & COCCYGEAL PLEXUSES
  48. 48.  Component: Sensory  Function: Smell  Opening to the Skull: Openings in cribriform plate of Ethmoid (facial bone)  Origin: Olfactory receptor nerve cells
  49. 49.  Component: Sensory  Function: Vision  Opening to the Skull: Optic Canal/foramina  Origin: Back of the eyeball
  50. 50.  Component: Motor  Function:  Raises upper eyelid  Turns eyeball upward, downward and medially  Constricts pupil  Accommodates the eye  Opening to the Skull: Superior orbital fissure  Origin: Anterior surface of the midbrain
  51. 51.  Component: Motor  Function: Assisting in turning eyeball downward and laterally  Opening to the Skull: Superior orbital fissure  Origin: Posterior surface of the midbrain
  52. 52.  Component: Sensory  Function:  Cornea  Skin of forehead  Scalp  Eyelids and nose  Mucous membranes of paranasal sinuses and nasal cavity  Opening to the Skull: Superior orbital fissure  Origin: Anterior aspect of the pons
  53. 53. o Component: Sensory o Function: o Skin of the face over maxilla o Teeth of the upper jaw o Mucous membrane of the nose, the maxillary sinus and palate o Opening to the Skull: Foramen ovale o Origin: Anterior aspect of the pons
  54. 54. o Component: a. Motor o Function: o Muscles of mastication o Mylo-hyoid: muscle from mandible to hyoid forming the floor of the mouth o Anterior belly of digastric: muscle under the jaw o Tensor tympani: is a muscle within the ear. It is contained in the auditory tube. Its role is to decrease sounds, such as those produced from chewing. o Opening to the Skull: Foramen Rotundum o Origin: Anterior aspect of the pons
  55. 55. • Component: b. Sensory • Function: • Skin of cheek • Skin over mandible and side of head • Teeth of lower jaw and TMJ • Mucous membrane of mouth and anterior part of tongue • Opening to the Skull: Foramen Rotundum • Origin: Anterior aspect of the pons
  56. 56.  Component: Motor  Function: Lateral rectus muscle turns eyeball laterally  Opening to the Skull: Superior orbital fissure  Origin: Anterior Surface of hindbrain between pons and medulla
  57. 57. Feature Somatic Motor Pathways Autonomic Pathways Direction of flow Efferent Efferent No. of neurons between CNS and effectors One Two Pre-ganglionic Post ganglionic Myelin sheath Present Pre-ganglionic: Present Post ganglionic: Absent Effectors Skeletal Muscles Smooth muscles, cardiac etc.
  58. 58. Hydrocephalus
  59. 59. FLEXOR (WITHDRAWL) REFLEXFLEXOR (WITHDRAWL) REFLEX IT IS A SPINAL REFLEX, AT THE TIME OF INJURY. THIS PULLS AWAY FROM THE PAINFUL STIMULI. THIS IS ALSO CALLED FLEXOR REFLEX BECAUSE FLEXOR MUSCLE OF THE UPPER EXTREMITY IS INVOLVED IN IT. A PAINFUL STIMULUS CAN TRIGGER BOTH IPSILATERAL (SAME SIDE) AND CONTRALETERAL (OPPOSITE SIDE) STABILIZE OF THE BODY WEIGHT . THIS IS ANTHIS IS AN

×