1. Parts of the Brain

2. Parts of the Brain
Cerebrum- higher- order thinking- intelligence, memory, sensory processing
2 halves connected by corpus callosum
4 lobes- frontal, parietal, temporal, occipital
Lobes are in the same location as corresponding skull bone

4. Lobes Frontal Lobe- Parietal (Par-eye-it-all) Lobe-
Consciousness, judgement, language, emotion, concentration, problem-solving
Broca’s Area- coordinates muscle movement for speech
Parietal (Par-eye-it-all) Lobe-
Integrating sensory information, hand-eye coordination
Temporal (Temp-oral) Lobe-
Smell and sound, memory of visual and auditory patterns
Occipital (Ox-ip-it-all) Lobe-
Vision

5. Hemisphere Dominance
Each hemisphere controls motor function for opposite side of body, dominant hemisphere opposite from dominant hand
Dominant (usually left) controls speech, reading, writing, analytical
Non-dominant- emotions, intuition, creativity

6. Diencephalon Located between cerebrum and midbrain
Glands contained in diencephalon:
Thalamus- receives sensory impulses, general awareness of touch sensations
Hypothalamus- homeostasis- controls hunger, heart rate, temperature, sleep, etc
Pituitary gland- endocrine gland, secretes important hormones
Pineal gland- endocrine gland, produces melatonin (related to sleep)

8. Parts of the Brain, cont’d
Cerebellum- Balance, posture, coordinates muscle movement
Brainstem-
Midbrain- visual and auditory reflex centers
Pons- regulates breathing, relays nerve impulses from peripheral nerves to brain
Medulla Oblongata- regulates heart rate, breathing, blood pressure (sends signals to these functions, while hypothalamus has more of a control function)

9. Brain Check-up...
What part of your brain contains your higher-order thinking skills?
If you are trying to recognize someone’s face, what area of your brain is going to be active?
If you are hungry, what part of your brain is signaling that?

10. The Spinal Cord and Nerves

11. Meninges-membranes that surround and protect brain and spinal cord, 3 layers:
Dura mater- outermost, tough connective tissue, blood vessels and nerves
Arachnoid mater- thin, in middle
Pia mater- very thin, innermost, many nerves and blood vessels serve brain and spinal cord

12. Spinal Cord
Thick bundle of nerves passing through opening at base of skull down through vertebral column
31 pairs of spinal nerves branch off, control limbs and trunk
Two-way communication system:
Ascending tracts: carry sensory info to brain
Descending tracts: carry nerve impulses from brain to muscles

14. Peripheral Nervous System Central Nervous System
Nerves that branch out from CNS and connect it to body parts
Two parts:
Somatic Nervous System- connects to skin and skeletal muscle, conscious activities
Autonomic Nervous System- connects to organs such as heart, stomach, intestines; unconscious activities
Brain and Spinal Cord

15. Cranial Nerves - originate from brainstem, 12 pairs, control face and neck

16. Nerve Plexus
Spinal nerves organized into plexuses- complex network of nerves, sort and recombine nerve fibers to correspond to each body part

17. Autonomic Nervous System
Controls heart rate, blood pressure, all unconscious activities
2 Parts-
Sympathetic- response to stress, “fight or flight”- speeds up heart, breathing, more blood to skeletal muscle
Parasympathetic- relaxation, slows down heart, breathing, more blood to digestive organs

18. Organize these terms into a concept map in your notes
Organize these terms into a concept map in your notes...think about how they are related hierarchically
Central nervous system
Peripheral nervous system
Parasympathetic nervous system
Sympathetic nervous system
Autonomic nervous system
Brain
Spinal cord
Nerve Plexuses
Meninges
Cerebellum
Cerebrum
Frontal Lobe
Occipital Lobe
Parietal Lobe
Temporal Lobe
Brain Stem

19. Anatomy of a Neuron

20. Neuron (Nerve Cell)

21. Parts of the Neuron
Dendrites- receive nerve impulses
Cell Body
Nucleus
Axon- sends nerve impulses, coated in myelin sheath
Axon Terminals- contact receptors of other cells
Myelin- whitish, fatty material that insulates axon and speeds up signal transmission
Schwann cells- cells wrapped around axon like a jelly roll, makes up myelin sheath
Nodes of Ranvier- gaps between Schwann cells
If a cell body were the size of a tennis ball, the axon would be a mile long

22. Types of Neurons
Sensory Neurons (afferent neurons)- cell bodies found in a ganglion (group of cell bodies) outside CNS
Dendrites are receptors (sense organs, pain receptors, skin receptors, etc)
Motor neurons (efferent neurons)- send messages from CNS to muscles and glands
Cell bodies in CNS, long axons
Interneurons- connect motor and sensory neurons, cell bodies located in CNS

23. Neuron Action Potentials

24. Membrane Potential
Charge difference between inside and outside of cell (called potential difference)
Larger concentration of Na+ ions outside cell and K+ ions inside cell causes charge
In a resting nerve cell, potential difference is called resting potential
Normal resting potential is -70 millivolts (mV)

25. Action Potential
Change in neuron membrane polarization and return to resting state is called an action potential
Chain of action potentials form nerve impulse

27. Action Potential
Stimuli (temperature, light, pressure, other neurons) decrease membrane potential
Decrease is called depolarizing
When threshold potential (-55 mV) is reached, stimulus is big enough to cause neuron to send a signal
Threshold triggers Na+ and K+ channels located in nodes of Ranvier to open and equalize charges
Na+ channels open faster, causing rapid depolarization
As K+ channels open, membrane becomes negatively charged once more (becomes repolarized)
Adjacent portions of axon are triggered and action potentials propagate down length of axon, making a nerve impulse
Signal “jumps” across Schwann cells from one Node of Ranvier to another
For a short time following impulse (1-2 milliseconds), a refractory period follows, when membrane returns to resting potential and no action potential can be triggered

28. Action Potential Video

29. Synapses and Neurotransmitters

30. What is a synapse? Synapse: gap between two neurons
Presynaptic neuron: neuron sending impulse
Postsynaptic neuron: neuron receiving impulse

31. Synaptic Transmission
Neurotransmitter: chemicals that carry out synaptic transmission
When action potentials reach axon terminals, neurons release neurotransmitters from vesicles
Neurotransmitters travel across synapse, attach to receptors on postsynaptic neuron dendrites

32. Neurotransmitters 2 types: Examples:
Excitatory- raise membrane potential
Inhibitory- lower membrane potential
Each neurotransmitter can be EXITATORY and INHIBITORY depending on what downstream neuron it is impacting.
Examples:
Acetylcholine- excitatory, muscle contraction
Norepinephrine- excitatory, increases sense of well-being, concentration
Serotonin- inhibitory, causes sleepiness
Dopamine- inhibitory, increases sense of well-being, pleasure