The Nervous System

1. The Nervous System IIA-2.1 Classify the major divisions and subdivisions of the nervous system. IIA-2.2 Differentiate the functions of the various subdivisions of the nervous system.

2. Nervous System • Central Nervous System (CNS) • Decision maker • Peripheral Nervous System (PNS) • Gathering information and transmitting CNS decisions to the other parts of the body • Nerves are associated with the PNS • Bundled axons that form neural “cables” connecting the CNS with muscles, glands, and sense organs

3. Nerves • Sensory neurons • Neurons that carry incoming information from the sensory receptors to the brain and spinal cord • Motor neurons • Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands • Interneurons • Neurons within the brain and spinal cord that communicated internally and intervene between the sensory inputs and motor outputs.

4. Central Nervous System Neural Networks A cluster of neurons which work together in a group Spinal Cord Information highway connecting the peripheral nervous system to the brain

5. Simple Reflex • Reflexes • A simple, automatic response to a sensory stimulus, such as a knee-jerk response.

6. Parts of the Nervous Systems • Somatic nervous system • The division of the PNS that controls the body’s skeletal muscles • Autonomic nervous system (ANS) • The part of the PNS that controls the glands and the muscles of the internal organs. • Sympathetic nervous system • The division of the ANS that arouses the body, mobilizing its energy in stressful situations • Parasympathetic nervous system • The division of the ANS that calms the body, conserving its energy

7. Autonomic Nervous System

8. The Endocrine System IIA-5.1 Describe how the endocrine glands are linked to the nervous system.

9. The Endocrine System • The body’s “slow” chemical communication system • A set of glands that secrete hormones into the bloodstream • Hormones- chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues • Can be identical to neurotransmitters • A close relative to the nervous system • Main organs • Adrenal glands • A pair of endocrine glands that sit above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress. • Pituitary glands • The most influential gland • Near the hypothalamus, controls and other endocrine glands and regulates growth. • Brain  pituitary  other glands  hormones  brain

11. The Brain and All its wonders!

12. Plasticity of the Brain • The brain has the ability to change, especially during childhood, by recognizing damage or by building new pathways based on experiences. • Neural tissue cannot regenerate itself, but it can reorganize. • I.E. – a person who is blind does not use their occipital lobe, this can be repurposed for the other senses. • Deaf people often have better peripheral vision than normal due to the temporal lobe reorganizing itself for vision. • Repurposes during severe trauma (i.e. losing a finger) • Neurogenesis – the formation of new neurons

13. Quick write • Neurogenesis allows us to form new brain neurons, and stem cells can develop into any type of brain cell. If a brain is damage and these stem cells are injected, there is a possibility (but no certainty) of regrowth and can help those who have had some form of brain trauma. Should we as humans be allowed to play god? Defend your position.

14. A brain divided • Lateralization – the division of a brain into 2 hemispheres. • Corpus Callosum • The large band of neural fibers connecting the two brain hemispheres and carrying messages between them • Split brains • A condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers connecting them. • Solved seizures which some patients were having.

17. Activity • As a table group, review each standard we have covered in the unit. • Write a question which you think you might see on the test.