Parts of the Brain

1. Parts of the Brain

2. The Nervous System Function: The nervous system controls and coordinates the functions throughout the body and responds to external and internal Stimuli.

3. Central Nervous System (CNS) Pg. 3

4. The Central Nervous System (CNS) • Main functions of the CNS: • conveys messages between brain and spinal cord; • processes info, problem solving • 2 structures make-up the CNS: • brain; • spinal cord • the skull and vertebrae protect these Pg. 3

5. Peripheral Nervous System (PNS) Pg. 4

6. Peripheral Nervous System • Function: receives info. from the environment and relays commands from the CNS to organs and glands • It lies OUTSIDEthe CNS • Includes all nerves and associated cells that are not part of the brain and spinal cord • *divided into sensory & motor divisions • Sensory: transmits impulses from sense organs to the CNS • Motor: transmits impulses from the CNS to muscles or glands Pg. 4

7. Somatic Nervous System (SNS) Pg. 5

8. Somatic Nervous System (SNS) • regulates activities that are under consciouscontrol Pg. 5

9. Autonomic Nervous System (ANS) Pg. 6

10. Autonomic Nervous System (ANS) • Regulates activities that are automatic/involuntary Pg. 6

11. Sympathetic Nervous System Hormone release, Adrenaline(Epinephrine), to prepare body for “Fight or Flight”

12. Parasympathetic Nervous System • Hormone release, Noradrenaline(norepinephrine), to counteract the effects of the adrenaline. Slow the body down once the stress is gone

13. Cerebrum • Responsible for voluntary (conscious) activities of body • Site of intelligence, learning and judgment Pg. 1

14. Lobes: • Frontal Lobe Functions: • Motor Functions • Higher Order Functions • Planning • Reasoning • Judgment • Impulse Control • Memory

15. Lobes: • Parietal lobe function: • Cognition • Information Processing • Pain and Touch Sensation • Spatial Orientation • Speech • Visual Perception

16. Lobes: • Temporal Lobe Function: • AuditoryPerception • Memory • Speech • EmotionalResponses • Visual Perception

17. Lobes: • Occipital Lobe Function: • Visual Perception • Color Recognition

18. Cerebellum • Back of the skull • Coordinates and balances actions of muscles so body can move gracefully and efficiently Pg. 1

19. Brain Stem • Connects brain and spinal cord (just below cerebellum • 2 regions: • pons -neural “switchboard” –regulates flow of info. Between brain and rest of body • medulla oblongata–controls heart rate, breathing, swallowing…etc. Pg. 1

21. Spinal Cord • Main communication link between brain and rest of body Pg. 1

22. Thalamus • Receives messages from all sensory receptors throughout body • Relays info. to proper region of cerebrum for further processing Pg. 1

23. Hypothalamus • Control center for recognition and analysis of hunger, thirst, fatigue, anger, body temp…etc. Pg. 1

24. Pituitary gland • “Master Gland” • Produces hormones that regulate other glands

25. Neurons/Nerve Impulses/Synapses Pg. 2

26. Neurons • Cells that carry messages throughout the nervous system • 3types: - 1st:sensory neurons- carry impulses from sense organs to brain; 2nd:motor neurons- carry impulses from brain to muscles/glands. 3rd: Interneuron: carry impulses between sensory and motor neurons (connects them) Pg. 2

27. sensory neurons- Interneuron motor neurons-

28. Parts of a neuron 1stcell body: largest part, contains nucleus and most of cytoplasm 2nddendrites: carry impulses toward the cell body Pg. 2

29. Parts of a Neuron cont. 3rd axons: carries impulses away from cell body. 4thmyelin sheath: (lipids) insulating membrane around axon There are small gaps in the myelin sheath along an axon called nodes • Schwann Cells– individual cells of the myelin sheath Pg. 2

30. Parts of a Neuron cont. • Axon Terminal- the ending of the nerve cell where the synapse is located. • One neuron can have dozens of dendrites but only one axon.*{bonus?}*

31. Nerve Impulses • Messages carried by the nervous system are electrical signals called impulses. • Impulse begins: neuron stimulated by environment or another neuron (impulse travels rapidly away from cell body) moves toward axon terminals and into the synapse. Pg. 2

32. The Synapse & Neurotransmitter • Synapse: the location at which a neuron can transfer an impulse to another cell • Neurotransmitter: chemicals used by a neuron to transmit an impulse across a synapse to another cell Pg. 2

33. The Sensory Organs

34. Touch • Response to a mechanicalstimulus. The skinis the largest sensory organ. Sensory receptors detect pressure, pain, heat, cold.

35. Smell • Response to a _chemical_____ stimulus. Sensory receptor cells are bathed in mucus and respond to different chemicals

36. Taste • Response to a _chemical_stimulus. Sensory receptors called _taste buds_ are located on the _tongue. Detect sweet, sour, salty, bitter

37. Vision • Response to a _light___ stimulus

38. Cornea– Light first passes through the _cornea_____, a transparent, protective covering which begins _focusing___ the light. The light then enters a chamber filled then enters a chamber filled with watery fluid called the _aqueoushumor______.

39. _Pupil_- Hole that light passes through. The size of the pupil is controlled by a ring of muscles known as the _iris___.

40. _Lens____ - Completes focusing of the light ray. There is also a thick jelly-like substance to help maintain the shape of the chamber known as the _vitreoushumor______.

41. Retina– Nerve tissue at the back of the eyeball that converts light energy to an _electricalimpulse. • Made up of two types of cells: Rods - Cells that detect _shape & movement_; are stimulated even in _dim_ light. Cones - Cells that detect _color_; provide a _sharp_ image; require _bright_ light for stimulation

42. Optic Nerve - Transmits the impulse to the _brain___.

43. Additional Structures • Sclera - _”White of the eye”; continuation of the _cornea____ • Choroid- Layer of blood vessels that _nourishthe eye.

44. Path Light takes through the Eye: • Cornea  aqueous humor  pupil  lens  vitreous humor  retina  Optic Nerve

46. Path that sound takes through the Ear

47. Hearing Response to a mechanical stimulation - sound waves • Sound waves first enter the outer ear and are funneled into the auditory canal.

48. Hearing • Causes vibrations of a membrane known as the tympanic membrane or eardrum. • Vibrations are then passed to three tiny bones → • hammer • anvil • stirrup

49. Hearing • The vibrations are transferred from the stirrup to another membrane known as the oval window.

50. Hearing • Finally, vibrations are converted to an electrical impulse in the cochlea, a snail-shaped sensory structure filled with fluid and tiny hairs. These hairs are pushed back & forth, producing electrical impulses.