Vertebrate Nervous System new 1 - Copy.pptx

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1. Vertebrate Nervous System

2. Stepwise Allocations: - Evolution - Anatomic Directions - Overall Structure ~Central Nervous System ~Peripheral Nervous System -Reflex Arcs

3. Evolution of Vertebrate Nervous System : Evolution of vertebrates can be explained on the basis of three characters named as: Bilateral symmetry Notochord Tubular nerve cord

4. Bilateral symmetry: Body plan that divides the animals body into right and left sides that are mirror images of each other.

5. Notochord It is a cartilaginous skeletal rod lying ventral to neural tube, present in all vertebrates during embryological phase but can be reduced or absent in adults. It basically turns to vertebral column in most of the vertebrate species.

6. Tubular Nerve Cord: During early evolution the spinal cord and brain begin as nerve cord.

7. The anterior end enlarges to form brain vesicles, and the rest becomes the spinal cord.

8. Unlike the spinal cord, which has changed little in structure during vertebrate evolution, the brain has changed dramatically. The ancestral vertebrate brain of fishes and early tetrapods expanded to form a deeply fissured and enormously intricate brain in the lineage leading to mammals. It reaches its greatest complexity in the human brain.

9. In vertebrates the sensory fibres and motor fibres leave the cord in dorsal and ventral roots. These roots unite in as nerves.

10. Anatomic Directions: Mammal and bird nervous system anatomically situated as explained in pictures

11. Reptilie and amphibian nervous system anatomically situated as explained in pictures

12. Overall Structure: The nervous system can be divided into two major regions the central and peripheral nervous systems. The central nervous system (CNS) is the brain and spinal cord T he peripheral nervous system (PNS) is everything else

13. Overall Structure: The brain is contained within the cranial cavity of the skull T he spinal cord is contained within the vertebral cavity of the vertebral column.

14. Overall Structure: These two regions within nervous system structures are often referred to as gray matter (the regions with many cell bodies and dendrites ) white matter (the regions with many axons).

15. Overall Structure: Nervous tissue, present in both the CNS and PNS contains two basic types of cells: neurons and glial cells. A glial cell is one of a variety of cells that provide a framework of tissue that supports the neurons and their activities. The neuron is the more functionally important of the two, in terms of the communicative function of the nervous system.

16. Basic Fuction : The nervous system is involved in R eceiving information about the environment around us (sensation) and G enerating responses to that information (motor responses). The nervous system can be divided into regions that are responsible for sensation (sensory functions) and for the response (motor functions).

17. Basic Fuction : Sensation The first major function of the nervous system is sensation—receiving information about the environment to gain input about what is happening outside the body (or, sometimes, within the body). The sensory functions of the nervous system register the presence of a change from homeostasis or a particular event in the environment, known as a stimulus.

18. Basic Fuction : Response The nervous system produces a response on the basis of the stimuli perceived by sensory structures . An obvious response would be the movement of muscles, such as withdrawing a hand from a hot stove, but there are broader uses of the term. The nervous system can cause the contraction of all three types of muscle tissue.

19. Basic Fuction : Response The nervous system produces a response on the basis of the stimuli perceived by sensory structures . An obvious response would be the movement of muscles, such as withdrawing a hand from a hot stove, but there are broader uses of the term. The nervous system can cause the contraction of all three types of muscle tissue.

20. Basic Fuction : Responses can be divided into those that are voluntary or conscious (contraction of skeletal muscle) and those that are involuntary (contraction of smooth muscles, regulation of cardiac muscle, activation of glands). Voluntary responses are governed by the somatic nervous system and involuntary responses are governed by the autonomic nervous system,

21. Basic Fuction : Integration Stimuli that are received by sensory structures are communicated to the nervous system where that information is processed. This is called integration. Stimuli are compared with, or integrated with, other stimuli, memories of previous stimuli, or the state of a person at a particular time. This leads to the specific response that will be generated.

22. Basic Fuction :

23. Peripheral nervous stystem

24. Peripheral nervous stystem I t is an other type of nervous system. The peripheral nervous system is the connection line between the central nervous system and the overall body parts. It includes nerve cell which are arise from the central nervous system.

25. Peripheral Nervous S ytem In V ertebrate It collect information and send commands containg nerve that extend to and from the spinal cord. On the basis of function and structure ,it is divided in to: i - Afferent nerve ii- Efferent nerve iii- Somatic nerve Iv-Autonomic nerve

26. Afferent Nerves It collect sensory information from the body and transfer to the CNS. It is also called sensory nerves.

27. Efferent Nerves It bring commands the CNS to the body. It is also called motar nerve.

28. Somatic Nerves(conscious control) Somatic nerve send motor commands from the CNS to voluntarily controlled muscles. It is made up of cranial and spinal nerve that contain motor nerve. without somatic nervous system animal are not able to respond to its environment.

29. A utonomic Nerves(Unconscious control) It is an involuntarily in function. It is also made up of cranial and spinal nerve that contain motor neuron. Under Unconscious control such as: Heart beat, blinking of eyes, etc. Autonomic nervous system is further divided in to two types. i ) sympathetic nervous system. Ii) parasympathetic nervous system.

30. Sympathetic Nervous System . It control the “fight or flight” reaction associated with the short term stress responses. Eg : an accelerated heart rate and inhibited digestion

31. Parasympathetic Nervous System . It control the “rest and digest” activities involved in conserving and restoring energy. The parasympathetic actually resets organ nervous system. Effect of the parasympathetic nervous system on target organ. Such as: slowing of heart rate and stimulation of digestion.

32. Diseases Of The Peripheral Nervous System There are a number of diseases and disorders that can effect the peripheral nervous system. Some of the conditions that can effect the PNS include: Diabetes Peripheral nerve injuries Tumors Vitamin deficiency

33. Symptoms : Symptoms of PNS diseases and disorders can include numbness pain, burning, sensitivity to touch, and muscles weakness

34. Reflex: Reflex action, is an involuntary and nearly instantaneous movement in response to any internal or external stimuli . Reflex Arc: A reflex is made possible by neural pathways its called reflex arcs which can act on an impulse before that impulse reaches the brain.

35. Parts O f R eflex Arc: There are five different parts of reflex arc: Sensor Sensory neuron Control center Motor neuron muscles

36. Sensor: Reflex start in structure called sensor. These structures detect different kinds of energy. Such as touch, heat, light, smell etc. Sensory N euron: Each reflex has a sensory neuron. These neuron begins a nerve impulse that travels to the spinal cord or to the brain. Such as eyes, ears, muscles and other body parts.

37. Control Center In the spinal cord the sensory neuron splits into at least three branches. Each branch forms a synapse with one of three different kinds of cells. One branch connects to a cell called an interneuron. These interneuron send a message up the spinal cord to let the cerebral cortex. Another branch goes to the motor neuron for the bicep and tricep muscles of the arm. The third branch goes to another interneuron that makes a connection to the motor neuron.

38. Motor Neuron This part of reflex are is called the output phase. The these things happen at once during the output phase. The nerve impulse to the motor neuron travels out to the biceps. The nerve impulse out is carried along an interneuron a short distance to the motor neuron for the biceps. A message travelling along interneuron starts its long trip to the cerebral cortex

39. Muscles: It is the part of reflex arc. A message from a motor neuron tell your muscles to contract and relex the biceps and triceps muscles.