1. Biology

2. The Nervous System Two main parts: Two main parts: Central Nervous System Central Nervous System Consists of the brain and spinal cord Consists of the brain and spinal cord Peripheral Nervous System Peripheral Nervous System Consists of nerve cells that send messages between the central nervous system and all the parts of the body Consists of nerve cells that send messages between the central nervous system and all the parts of the body

3. Neurons Neurons- nerve cells Neurons- nerve cells Send and receive messages from other structures in the body such as muscles and glands Send and receive messages from other structures in the body such as muscles and glands

4. Neurons Components of a neuron Components of a neuron Cell Body- produces energy that fuels the activity of the cell Cell Body- produces energy that fuels the activity of the cell Dendrites- thin fibers which branch out of the cell, receive information from other neurons and pass the message through the cell body Dendrites- thin fibers which branch out of the cell, receive information from other neurons and pass the message through the cell body Axon- carries messages away from the neuron, single fiber Axon- carries messages away from the neuron, single fiber Myelin- covering of the axon, insulates and protects the axon, helps to speed up the transmission of the message Myelin- covering of the axon, insulates and protects the axon, helps to speed up the transmission of the message Axon terminal- small fibers branching out from an axon Axon terminal- small fibers branching out from an axon

5. Types of Neurons Sensory- carry messages from sense organs to spinal cord or brain Sensory- carry messages from sense organs to spinal cord or brain Motor- carry messages from spinal cord or brain to muscles or glands Motor- carry messages from spinal cord or brain to muscles or glands Interneurons- carry messages from one neuron to another and do most of the work of the nervous system Interneurons- carry messages from one neuron to another and do most of the work of the nervous system

6. How do Neurons communicate? Neurons send messages across synapses through the release of neurotransmitters Neurons send messages across synapses through the release of neurotransmitters Chemicals that are stored in sacs in the axon terminal Chemicals that are stored in sacs in the axon terminal

7. Nerve Impulses Absolute refractory period- after one cell firing, it will not fire again regardless of how strong the incoming message is Absolute refractory period- after one cell firing, it will not fire again regardless of how strong the incoming message is Relative refractory period- time when neuron is returning to normal and may refire if message is stronger then usual Relative refractory period- time when neuron is returning to normal and may refire if message is stronger then usual All or none law- a neuron fires at full capacity or does not fire at all All or none law- a neuron fires at full capacity or does not fire at all

8. Firing of a nerve cell Dendrite or cell body picks up message Dendrite or cell body picks up message If message is strong enough, neuron fires and impulse starts down the axon If message is strong enough, neuron fires and impulse starts down the axon Out the end of the axon terminal to the synaptic knob Out the end of the axon terminal to the synaptic knob On to the next nerve cell On to the next nerve cell

9. Central Nervous System 2 major parts 2 major parts Central Nervous System- brain and spinal cord Central Nervous System- brain and spinal cord Peripheral Nervous System- connects brain, spinal cord to every other part of the body Peripheral Nervous System- connects brain, spinal cord to every other part of the body

10. Brain Areas of the Brain Areas of the Brain Hindbrain- co-ordinate motor activity, posture, equilibrium, sleep patterns, and regulate unconscious functions (ex. blood circulation and breathing) Hindbrain- co-ordinate motor activity, posture, equilibrium, sleep patterns, and regulate unconscious functions (ex. blood circulation and breathing) Midbrain- vision, hearing, motor control, sleep/awake cycle, arousal (alertness), and temperature regulation Midbrain- vision, hearing, motor control, sleep/awake cycle, arousal (alertness), and temperature regulation Forebrain- controls cognitive, sensory, and motor functions, regulate body temperature, reproductive functions, eating, sleeping, and display of emotions Forebrain- controls cognitive, sensory, and motor functions, regulate body temperature, reproductive functions, eating, sleeping, and display of emotions

11. Brain Parts of the Brain Parts of the Brain Amygdala- storing & classifying emotional memories, produces emotions Amygdala- storing & classifying emotional memories, produces emotions Hippocampus- memory formation, classifying information, long-term memory Hippocampus- memory formation, classifying information, long-term memory Thalamus- sensory signals, visual information, information from skin and internal organs, motor control Thalamus- sensory signals, visual information, information from skin and internal organs, motor control Hypothalamus- metabolic processes, body temperature, hunger, thirst, fatigue, anger, and circadian cycles Hypothalamus- metabolic processes, body temperature, hunger, thirst, fatigue, anger, and circadian cycles

12. Brain Cerebellum- regulates & coordinates movement, posture, and balance Cerebellum- regulates & coordinates movement, posture, and balance Pons- relays messages to other parts of the brain, controls arousal, and respiration Pons- relays messages to other parts of the brain, controls arousal, and respiration Medulla Oblongata- heart rate, respiration, blood pressure, swallowing, vomiting, and defecation, relay station for nerve signals going to/from the brain Medulla Oblongata- heart rate, respiration, blood pressure, swallowing, vomiting, and defecation, relay station for nerve signals going to/from the brain

13. Brain Lobes of the Brain Lobes of the Brain Occipital- receives and interprets visual information Occipital- receives and interprets visual information Temporal- controls hearing and some processing of visual and olfactory information Temporal- controls hearing and some processing of visual and olfactory information Parietal- responds to sensations of touch bodily position Parietal- responds to sensations of touch bodily position Frontal- responsible for voluntary movement- attention, goal- directed behavior, and appropriate emotional experiences Frontal- responsible for voluntary movement- attention, goal- directed behavior, and appropriate emotional experiences

14. Brain Hemispheres Hemispheres Left- right-hand touch and movement, speech, language, and writing Left- right-hand touch and movement, speech, language, and writing Right- left-hand touch and movement, spatial construction, non-verbal imagery, and face recognition Right- left-hand touch and movement, spatial construction, non-verbal imagery, and face recognition

15. Peripheral Nervous System Carries messages to and from the Central Nervous System Carries messages to and from the Central Nervous System Made of two major parts Made of two major parts Somatic Nervous System Somatic Nervous System Autonomic Nervous System Autonomic Nervous System

16. Somatic Nervous System Composed of all sensory (afferent) neurons that carry information to the CNS and all the motor (efferent) neurons that carry messages from the CNS to the skeletal muscles of the body Composed of all sensory (afferent) neurons that carry information to the CNS and all the motor (efferent) neurons that carry messages from the CNS to the skeletal muscles of the body The senses have their origin in the somatic part of the Peripheral Nervous System The senses have their origin in the somatic part of the Peripheral Nervous System

17. Autonomic Nervous System Composed of all the neurons that carry messages between the CNS and all the internal organs of the body (glands and smooth muscles such as the heart and digestive system) Composed of all the neurons that carry messages between the CNS and all the internal organs of the body (glands and smooth muscles such as the heart and digestive system) Important in breathing, blood flow, and emotions Important in breathing, blood flow, and emotions Has two branches- sympathetic and parasympathetic Has two branches- sympathetic and parasympathetic Both are involved in controlling and integrating actions of the glands and smooth muscles Both are involved in controlling and integrating actions of the glands and smooth muscles

18. Sympathetic and Parasympathetic Nervous Systems Sympathetic Sympathetic Tell the body to prepare for an emergency Tell the body to prepare for an emergency Heart pounds, breathe faster, pupils enlarge, & digestion stops Heart pounds, breathe faster, pupils enlarge, & digestion stops Tells the endocrine system to release chemicals into bloodstream Tells the endocrine system to release chemicals into bloodstream Connect to every internal organ of body Connect to every internal organ of body Parasympathetic Calms the body down after stress

19. The Endocrine System Consists of glands which secrete hormones into the bloodstream Consists of glands which secrete hormones into the bloodstream Hormones- stimulate growth and affect behavior and emotional reactions Hormones- stimulate growth and affect behavior and emotional reactions produced by different glands- pituitary, thyroid, adrenal, testes, and ovaries produced by different glands- pituitary, thyroid, adrenal, testes, and ovaries

20. Pituitary Gland Lies below the hypothalamus Lies below the hypothalamus Considered the “Master Gland” Considered the “Master Gland” Secretes different hormones Secretes different hormones Growth- regulates growth of muscles, bones, and glands Growth- regulates growth of muscles, bones, and glands Prolactin- stimulates production of milk in nursing women Prolactin- stimulates production of milk in nursing women Oxytocin- stimulates labor in pregnant women Oxytocin- stimulates labor in pregnant women

21. Thyroid Gland Produces thyroxin Produces thyroxin Affects the body’s metabolism- the rate of converting food to energy Affects the body’s metabolism- the rate of converting food to energy Low production can lead to hypothyroidism- can cause people to be overweight Low production can lead to hypothyroidism- can cause people to be overweight High production can lead to hyperthyroidism- can cause excitability, inability to sleep, and weight loss High production can lead to hyperthyroidism- can cause excitability, inability to sleep, and weight loss

22. Adrenal Gland Located above the kidneys Located above the kidneys Secretes cortical steroids- increase the resistance to stress and promote muscle development, can cause the liver to release stored sugar in emergencies Secretes cortical steroids- increase the resistance to stress and promote muscle development, can cause the liver to release stored sugar in emergencies Produce adrenaline and noradrenaline Produce adrenaline and noradrenaline Arouse the body for an emergency Arouse the body for an emergency Adrenaline- can intensify emotions (fear & anxiety) Adrenaline- can intensify emotions (fear & anxiety) Noradrenaline- raises blood pressure Noradrenaline- raises blood pressure

23. Testes and Ovaries Testes- males Testes- males Ovaries- females Ovaries- females Each produces hormones- testosterone, estrogen, and progesterone Each produces hormones- testosterone, estrogen, and progesterone

24. Testosterone Testosterone- male sex hormone, small amount found in females Testosterone- male sex hormone, small amount found in females Influences the development of sex organs (if secreted child will be male, if not- female) Influences the development of sex organs (if secreted child will be male, if not- female) Aids in growth of muscle and bone, primary and secondary sex characteristics Aids in growth of muscle and bone, primary and secondary sex characteristics Primary sex characteristics- directly involved in reproduction Primary sex characteristics- directly involved in reproduction Secondary sex characteristics- distinguish males from females Secondary sex characteristics- distinguish males from females

25. Estrogen & Progesterone Female sex hormones but small amounts are found in males Female sex hormones but small amounts are found in males Females- ovaries produce estrogen and progesterone Females- ovaries produce estrogen and progesterone Males- testes produce estrogen and progesterone Males- testes produce estrogen and progesterone

26. Estrogen & Progesterone Estrogen-Development of primary and secondary sex characteristics Estrogen-Development of primary and secondary sex characteristics Progesterone- stimulates growth of female reproductive organs and prepares the body for pregnancy Progesterone- stimulates growth of female reproductive organs and prepares the body for pregnancy Both regulate menstrual cycle and vary during the cycle Both regulate menstrual cycle and vary during the cycle Changing levels of estrogen are linked to PMS Changing levels of estrogen are linked to PMS Estrogen is connected to cognitive functioning and feelings of well-being among women Estrogen is connected to cognitive functioning and feelings of well-being among women