What does a Nervous System do for you?

1. What does a Nervous System do for you? • Detect (sense) changes in the environment (light, sound, smell, taste, touch, heat) • Detect (sense) changes in the internal environment (blood pressure, blood chemistry, temperature, etc.) • Integrate and evaluate sensory information • Plan, problem-solve, predict • Store and retrieve information (memory) • Control contractions of skeletal muscles (movements / behavior) • Control internal glands, muscles (heart rate, hormone secretions, metabolism)

2. The Nervous System Organization Central Nervous System - completely surrounded by bone - suspended in cerebrospinal fluid - covered by meninges - protected by “blood-brain barrier” Peripheral Nervous System - nerves leaving and entering the CNS - motor nerves = control muscles and glands - sensory nerves = transmit information to the CNS from sensory receptors. - emerge from cranial and spinal nerves

3. How the Peripheral and Central Nervous Systems Interact

5. Cells of The Nervous System Two neurons releasing neurotransmitters that act on a third neuron. The first two neurons could be in the Central Nervous System, and the third might be a motor neuron leading out to a muscle or gland. • Neuroglia (supporting cells) • Provide physical support to neurons • Provide electrical insulation to neurons • - May be involved in processes such as memory. • Neurons • Detect physical and chemical changes in their environment • Transmit electric impulses (action potentials) from one end to the other (one cell may be more than 3 feet long) • - Communicates with other neurons, muscles and glands using chemicals called neurotransmitters.

6. Motor neurons have their cell bodies in the spinal cord, but their axons extend outward into the body to stimulate muscles or glands. Spinal cord smear Dendrites Microglia

7. Terminal of a motor neuron axon - where the neuron stimulatesthe muscle cell to contract. Axon Axonterminus Musclecell Neuromuscular junction(motor end plate)

8. Pyramidal cells (neurons) of the cerebral cortex

9. Action potentials are tiny electric impulses produced by neurons. They are used for transmitting information away from the cell body and toward the axon terminals. When they reach the axon terminals, the action potentials cause the release of neurotransmitter from the terminals. When a neuron is stimulated, not every stimulus will cause an action potential. The stimulus must be sufficient to cause the neuronto reach threshold. Only then will an action potential be produced.

10. Cells of the Central Nervous System

11. Microglia - immune-like cells

12. Oligodendrocyte produce myelin sheath

13. Astrocyte - blood brain barrier

14. Ependymal cells - line ventricles and help produce cerebrospinal fluid

16. A Single Action Potential

17. The Na/K ATPase pumps set up the necessary conditions across the membrane of a neuron so that the neuron will be capable of producing an action potential. • High Na outside (3 ions pumped out) • High K inside (2 ions pumped in) • Produces a transmembrane potential (-70 mV)

21. The Ventricles of the Brain Are Shown in Dark Blue Lateral Ventricle Third Ventricle Fourth Ventricle

22. Transverse Section Showing Lateral Ventricles

25. Central Sulcus Gyrus (ridge) Sulcus (groove) Parietallobe Frontallobe Lateral sulcus Temporallobe Occipitallobe cerebellum

26. cerebrum Central Sulcus Gyrus(ridge) Sulcus (groove) Lateral Fissure Transverse Fissure Pons cerebellum Medulla oblongata

27. Post-Central Gyrus Pre-Central Gyrus Parietal Lobe Frontal Lobe Temporal Lobe Occipital Lobe

28. Basal Nuclei are Found Deep Below the Cerebrum

30. Limbic System - amygdala - hippocampus - cingulate gyrus - hypothalamus

33. Corpus Callosum Thalamus Hypothalamus Pituitary Pons Midbrain Medulla oblongata

34. Olfactorybulb Opticnerve pons Medullaoblongata cerebellum

35. Inferior View of Brain and Cranial Nerves

36. Nervous System showing spinal nerves emerging from the spinal cord Small segment of spinal cord Showing two pair of spinal nerves

37. Location of spinal cord inside canal of vertebra

38. White matter Dorsal root ganglion Ventral root Gray matter Dorsal root

39. Organization of the Spinal Cord dorsal root Sensory neuroncell body Dorsal root ganglion sensory Spinal nerve motor Ventralroot Motor neuroncell body

40. Simple Knee Jerk Reflex Coordinated by the Spinal Cord Dorsal root Dorsal root ganglion Sensory neuron Quadriceps muscle Motor neuron Ventral root

41. Withdrawal Reflex interneuron