Your Amazing Brain

1. Your Amazing Brain • Receives information – within a fraction of a second, too minuscule to measure • Acts on the external universe – allows you to cry, walk, play a musical instrument • Utilizes language – one of your most advanced functions • Possesses emotions – creates your affective universe

2. Your Amazing Brain • Thinks –is responsible for your memory, intelligence, your thoughts • Controls your autonomic functions – heart rate, breathing, homeostasis • Controls your immune system – protects you from viruses

5. Peripheral Nervous System • Handles the CNS’s input and output. • Contains all the portions of the NS outside of the brain and spinal cord. • Contains sensory nerves and motor nerves • Divided into autonomic nervous system and somatic nervous system.

6. Sensory Nerves (to the brain) Carry messages from special reporters in the skin, muscles, and other internal and external sense organs to the spinal cord and then to the brain Motor Nerves (from the brain) Carry orders from CNS to muscles, glands to contract and produce chemical messengers Peripheral Nervous System

7. Somatic NS Consists of nerves connected to sensory receptors and skeletal muscles Permits voluntary action (writing your name) Autonomic NS Permits the involuntary functioning of blood vessels, glands, and internal organs such as the bladder, stomach and heart Peripheral Nervous System

8. Sympathetic NS Like the accelerator of your car Mobilizes the body for action Increases heart rate Elevates blood pressure Parasympathetic NS Like the brakes in your car Slows the body down to keep its rhythm Enables the body to conserve and store energy Autonomic Nervous System

9. Sympathetic NSand Emotion • You perceive the sensory stimulus. • The adrenal gland sends two hormones: epinephrine and norepinephrine. • They activate the sympathetic nervous system. • That produces a state of arousal or alertness that provides the body with the energy to act (the pupils dilate, the heart beats faster, and breathing speeds up).

11. Central Nervous System • The Spinal Cord • The Brain

12. The Spinal Cord • Protected by a column of bones • Produces some behaviors of its own without the help of the brain • These spinal reflexes are automatic, requesting no conscious effort • Sometimes they are influenced by thought and emotion • Example: touching a hot iron

13. The Brain • Areas of the Brain • The Four Lobes of the Brain • Lateralization

15. The Hindbrain • Medulla – breathing, heart rate • Pons – sleeping, walking, dreaming • Riticular Activating System – alertness, attention • Cerebellum – balance, coordination for the muscles

16. The Forebrain • Thalamus Direct sensory messages to higher centers in the brain The sight of sunset is directed to a visual area The only sense that completely bypasses the thalamus is the sense of smell, which has its private switching station, the olfactory bulb

17. The ForebrainThe Limbic System The Amygdala Responsible for evaluating sensory information It determines its emotional importance It makes the decision to approach or to withdraw Its initial response may be overridden by the appraisal of the cerebral cortex The Hippocampus The gate way to memory The Hypothalamus It is involved with drives associated with survival such as hunger, thirst, emotion, sex, and reproduction

18. The ForebrainThe Limbic System

19. The Endocrine System

20. The Endocrine System • The body’s slow chemical communication system; a set of glands that secrete hormones into the blood stream.

21. The Endocrine SystemA Set of Glands Thyroid gland – affects metabolism Pancreas – regulates the level of sugar in the blood Parathyroids – help regulate the level of calcium in the blood Ovary – secretes sex female hormones (estrogen) Testes – secrete sex male hormone (Androgens)

22. The Endocrine SystemA Set of Glands The Adrenal Glands A pair of endocrine glands just above the kidney They secrete epinephrine and norepinephrine which help to arouse the body in times of stress.

23. The Endocrine SystemA Set of Glands The Pineal Gland Helps secrete melatonin which helps to regulate daily biological rhythms and promotes sleep.

24. The Endocrine SystemA Set of Glands The Pituitary Gland A sort of master gland It is cherry-sized endocrine gland The hormones it secretes affect growth and the secretion of other endocrine glands The real boss is the hypothalamus

25. Feedback System

26. The Forebrain • The Cerebrum Higher forms of thinking take place in it It is divided into two halves called the cerebral hemispheres that are connected by a large band of fibers called the corpus callosum They have different tasks (lateralization)

27. The Forebrain • The Cerebral Cortex The cerebrum is covered by several thin layers of densely packed cells known as the cerebral cortex On each cerebral hemisphere, deep fissures divide the cortex into 4 lobes

29. The Four Lobes of theCerebral Cortex

31. Functions of the Cortex Motor Cortex – an area of the frontal lobes that controls voluntary movements. It sends messages out to the body. When stimulating, specific parts of the region in the left or right hemisphere, specific body parts moved on the opposite side of the body.

32. Functions of the Cortex Sensory Cortex – the area at the front of the parietal lobes that receives, registers, and processes body sensations. Association Functions – areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.

33. Functions of the Cortex Language 1- Broca’s Area – an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech 2- Wernicke’s Area – a brain area involved in language comprehension and expression; usually in the left temporal lobe.

34. Specialization and Integration in Language 1- Visual cortex – receives written words as visual stimulation. 2- Angular gyrus – transforms visual representations into an auditory code. 3- Wernicke’s area – interprets auditory code. 4- Broca’s area – controls speech muscles via the motor cortex. 5- Motor cortex – word is pronounced.

35. Left Hemisphere Verbal competence Speaking, reading, thinking & reasoning Processes info in sequence One piece of data at a time logical Right Hemisphere Nonverbal areas Comprehension, spatial relationships, drawing, music, emotion Processes info. As a whole intuitive Lateralization

36. Left Hemisphere Important for the expression of positive emotion Damage to the L.H. leads to loss of the capacity of joy. Activation in the L.H. leads to tendencies to approach other people. Right Hemisphere Important for the expression of negative emotion Damage to the R.H. may make people euphoric. Activation in the R.H. leads to tendencies to withdraw from people. Emotion and Lateralization

40. Neurons • The NS is made up in part of neurons • They are held in place by glial cells • The Function of Glial Cells: • Provide neurons with nutrients • Insulate neurons • Remove cellular debris when neurons die

41. The Structure of the Neuron • 1- Dendrites Act like antennas receiving messages • 2- The Cell Body Contains the biochemical machinery to keep the neuron alive • 3- The Axon Transmits messages away from the cell body to other neurons

42. How Neurons Communicate

43. Myelin Sheath • Surrounds the axons • A layer of fatty material, which is derived from glial cells • There are 2 purposes of the myelin sheath: • To prevent signals from adjacent cells from interfering with each other • To speed up the production of neural impulses

44. Stop! • Is the brain capable of reorganizing itself if damaged?

45. Plasticity • When one brain area is damaged, other areas may in time reorganize and take over some of its functions. • If neurons are destroyed, nearby neurons may partly compensate for the damage by making new connections that replace the lost ones. • Examples: How the sense of touch in blind men invades the visual part of the brain. How the brain struggles to recover from a minor stroke.

46. Stop! • Could damaged neurons in the central nervous system multiply and grow back?

47. Precursor Cells(Immature Cells) • Precursor cells can give birth to new neurons when immersed in a growth-promotion protein • Physical and mental exercise promote the survival and the production of new precursor cells • Stress can prohibit the production of new cells • Nicotine can kill precursor cells

48. Chemical Messengers in the NS • Neurotransmitters • Endorphins • Hormones

49. Neurotransmitters • Neurotransmitters travel from one neuron to another. Changes occur in the receiving neuron’s membrane, • The ultimate effect is either: • Excitatory: the probability that the receiving neuron will fire increases • Inhibitory: the probability that the receiving neuron will fire decreases

50. Neurotransmitters Serotonin Sleep, appetite, sensory perception, temperature regulation, pain suppression, and mood Dopamine Voluntary movement, learning, memory, and emotion Acetylcholine Muscle action, cognitive functioning, memory, and emotion