Nervous System Anatomy

1. Nervous System Anatomy

2. Breakdown: Central Nervous System (CNS) Peripheral Nervous System (PNS) Somatic Nervous System Autonomic Nervous System Sympathetic N.S. Parasympathetic N.S. • Brain • Spinal Cord

4. Function of the CNS: • Spinal Cord • Conducts sensory information to the brain • Conducts motor information to the brain • Skeletal Muscle • Cardiac Muscle • Smooth Muscle • Glands • Minor reflex center

5. Functions of the CNS: • Brain • Receives sensory input from Spinal Cord and own nerves (e.g. olfactory/optical nerves) • Process information • Generates and coordinates appropriate responses

6. Functions of the PNS: Somatic Nervous System • Regulate body movement • Control of skeletal muscle • Reception of external stimuli (i.e. the senses!!) Summary: RECEIVE and REACT to the WORLD around us!!!

7. Functions of the PNS: Autonomic Nervous System • Innervates: • Cardiac Muscle • Smooth Muscle • Glands • Regulates hormone levels • Homeostasis!!

8. Functions of the PNS: Sympathetic Nervous System Parasympathetic Nervous System Returns body to normal after Sympathetic response Vagus Nerve – originates in Medulla Oblongata, can play a role in controlling inflammation • Localized adjustments and reflex adjustments of cardiovascular system • Whole system response: Fight or Flight

10. The Brain

11. Major Divisions • The brain of all vertebrates develops from three swellings at the anterior end of the neural tube of the embryo. From front to back these develop into the: • Forebrain (Prosencephalon) • Cerebral Hemispheres: Telencephalon and Diencephalon • Midbrain (Mesencephalon) • Substantianigra, Ventral tegmental area (VTA) • Hindbrain (Rhombencephalon) • Medulla oblongata, Pons, Cerebellum

13. Structures of the Hindbrain

14. Medulla Oblongata • Rhythmic stimulation of intercostals and diaphragm • Regulate heartbeat • Regulate bloodflow (diameter of arterioles)

15. Pons • Relays information from eyes, ears, and touch receptors from cortex to cerebellum

16. Cerebellum • Functions: • Coordination of voluntary movement • Motor-learning • Balance • Reflex memory • Posture • Timing • Contains as many neurons as rest of brain combined! • Associated with Damage: • Loss of fine coordination • Tremor • Inability to walk • Dizziness (vertigo) • Slurred speech

17. Cerebellum

19. Midbrain • SubstantiaNigra: • Helps “smooth” out body motions • Ventral Tegmental Area (VTA): • One of the pleasure centers of the brain (dopamine releasing neurons)

20. Brain Stem • Midbrain • Pons • Medulla oblongata

21. Forebrain: Telencephalon • Cerebrum • 4 lobes • Frontal • Parietal • Occipital • Temporal

22. Frontal Lobe • Higher cognitive functions • Attention • Conscious thought • Voluntary movement • Decision making • Language • Planning • Problem-solving • Many more! • Associated with damage: • Paralysis • Loss of spontaneity • Mood changes • Inability to express language • Atypical social skills and personality traits

24. Parietal Lobe • Perception/Integration of somatosensory information (e.g. touch, pressure, temperature, pain) • Visuospatial processing • Spatial attention • Spatial mapping • Number representation • Associated with Damage: • Inability to locate and recognize objects, events, and parts of the body • Difficulty in discriminating between sensory information • Disorientation • Lack of coordination

25. Parietal Lobe

26. Occipital Lobe • Vision! • Associated with Damage: • Hallucinations • Blindness • Inability to see color, motion, or orientation • synesthesia

27. Occipital Lobe

28. Temporal Lobe • Recognition • Perception (hearing, vision, smell) • Understanding language • Learning and Memory • Associated with Damage: • Difficulty understanding speech, faces, objects • Inability to attend to sensory input • Persistent talking • Long and short-term memory loss • aggression

29. Temporal Lobe

31. Forebrain: Diencephalon • Thalamus • Hypothalamus • Pituitary Gland

32. Hypothalamus • Hunger • Thirst • Body temperature • Arousal • Parenting • Perspiration • Blood pressure • Beartrrate • Shivering • Pupil dilation • Circadian rhythms • Aggression • Chronic stress • Hypothermia • Hypersomnia • Lethargy • Self-mutilitation • Weight gain/loss

33. Hypothalamus

35. Thalamus • Relaying motor/sensory information • Memory • Alertness • Consciousness • Contributes to perception and cognition • Associated with Damage: • Amnesia • Apathy • Coma • Dementia • Difficulty speaking • Loss of alertness and activitaion • Sleepiness • Impaired processing of sensory information • Inattention • Impaired movements/posture • pain

36. Thalamus

37. Thalamus

38. Pituitary Gland • Secretes hormones • Referred to as the “master gland” • Associated with Damage: • Loss of hormonal regulation in many areas of the body

39. Pituitary Gland

40. Crossing Over • “Impulses reaching the spinal cord from the left side of the body eventually pass over to tracts running up to the right side of the brain and vice versa. In some cases this crossing over occurs as soon as the impulses enter the cord. In other cases, it does not take place until the tracts enter the brain itself.” • How is this possible??? • Corpus Callosum!!

41. Corpus Callosum • Connects right and left hemisphere and allows information to pass between them • Associated cognitive disorders: • Coma or vegetative state • Schizophrenia • Psychotic episodes • Memory impairment • Split-brain syndrome

42. Corpus Callosum