review

Frontal lobe:

• Lies anterior of the central sulcus

• Motor cortex

• Consist of primary motor cortex, pre motor cortex, prefrontal cortex, and brocas area

  • Pre-motor cortex: interprets the movement you want to preform from memory, sends the information to the primary motor cortex

  • Primary motor cortex:  also known as the pre-central gyrus, carries out the function that pre-motor cortex told it to preform to move skeletal muscle

  • Prefrontal cortex: area used for learning, solving complex problems, working memoryl task management, cognitive processing, learned behaviors, development depends on feedback from social environment

  • Brocas area: used to speak and understand written language, only present in the dominant hemisphere

• Lateral corticospinsal pathway carries information from the pre central gyrus to preform a movement

Parietal lobe

• Lies posterior to the central gyrus

• Sensory area

• primary somatosensory cortex

• Somatosensory association cortex

• Pathways: dorsal collum medial lemniscal pathway and spinothalmatic pathway

  • Primary somatosensory cortex: detects pain, temperature, discriminative touch, crude touch, pressure, capable of spatial discrimination

    • Sensory information sent to specific areas of the post-central gyrus

  • Somatosensory association cortex: stores memories about specific sensations and sensory, gives cortex sensory inout, compares to prior experience

• Information from the two pathways are brought up to the post-central gyrus

• Know which area of the post-central gyrus relates to which body part

Occipital lobe:

• Sensory area

• Visual area

• Consists of the primary visual cortex and the visual association cortex

  • Primary visual cortex: receives information from the retina of the eye; distinguishes intensity

  • Visual association cortex: uses memories to make sense of what you are seeing from past experiences, then sends this information to the frontal lobe

Temporal lobe:

• Auditory area and olfactory

• Auditory area: Primary auditory cortex and the auditory association cortex

  • Primary auditory cortex: receives information from the inner ears as loudness, pitch ands location

  • Auditory association cortex: uses working memory to make sense of the sound from past experiences

• Olfactory area: located on the medial side of the temporal lobe near the insulation; responsible for odor and strength of odor

Insula:

• Responsible for taste and vestibular organ information such as thirst and hunger , gustation

Assosiation areas:

• Anterior assosiation area (pre-frontal cortex)

• Posterior assosiation area

• Limbic association area

Anterior assosiation area

• Located in the frontal lobe

• Used for cognitive thinking, problem solving, working memory, higher order thinking

Posterior association area

• Found in areas of the parietal, occipital, and temporal lobes

• Used for recognizing patterns and faces and localizing us in space

• Wernickes area: used for understanding spoken language

Limbic association area

• Part of the limbic system

• Used for emotions

  • amygdala: responsible of negative association reactions (fear, fight or flight)

  • hippocampus: used for creating long term memories

  • Cingulate gyrus: used for recognizing negative facial expressions

Hemispheres

• Right hemisphere: responsible for artistic skills and intuition

• Left hemisphere: used for math, language, and logic

White matter fibers within the brain

• Association fibers: send messages to the multiple places in one hemisphere

• Commissual fibers: transfer messages from one hemisphere to another

• Projection: sends messages acceding and decending

• Decuseation pyramid: area where the fibers cross over

Basal gangli

• Use fortregulating motor movement and exaggeration of limbs

  • Substantia nigra: produces melanin

  • Assosiation with diencephalon (subthalmatic nuclei)

Brain development in an embryo

• Starts as a neural tube filled with fluid that becomes the cerebral aqueduct

• Telencephalon: develops into the cerebrum

• diensephalon: develops into the diencephalon (thalamus, hypothalamus, epithalamus)

• Mesencephalon: develops into midbrain and pons

• metencephalon: develops into the cerebellum

• myencephalon: develops into the medulla

• Cordol: develops into the spinal cord

Ventricles:

• Lateral ventricles connect to the third vertical via the interventrical foramen

• Third ventricle and fourth ventricle connected via the cerebral aqueduct

• Lateral apendure: allows CSF to leave ventricles

9/12/2026

Diencephalon:

• Part of the forebrain

• Contains the thalamus, hypothalamus, and the epithalamus

  • Thalamus: used as a relay center for sensory pathways; the thalamus sends the pathways to specific parts off the cerebrum\

  • Hypothalamus: used in regulating emotions and autonomic functions; can detect changes in the blood because it lacks a blood-brain barrier, regulates hormones

  • Epithalamus: houses the pineal gland, which secretes melatonin to regulate sleep cycle

Midbrain:

• Contains cerebral peduncles, superior and inferior colliculi, and the superior cerebellar peduncle

  • Cerebral peduncle: contains the pyramidal motor tracts, which send motor responses to the brain stem and spinal cord

  • Superior cerebellar peduncle: connect the cerebellum to the midbrain

Pons:

• Used in regulating breathing

• Contains the medial leminscal, superior and middle cerebellar peduncle, and fibers from pyramidal tract (used in corticospinal pathway)

Medulla:

• Used to regulate autonomic functions of the cardiovascular system and the respiratory system

• Contain desiccation of pyramids: corticspinal tracts cross over

• Contains more medial leminscal neurons

9/13/2026

Drawing neurons and parts of a neuron

Ion channels

• Leakage channels: always open

• Chemically gated channels: only opened when triggered by a neurotransmitter (found mostly on cell bodies and dendrites)

• Voltage gated channels: open and close in response to a change in membrane potential (found on axons)

• Sodium potassium pump: 3 Na+ out, 2 K+ in

Changes in resting membrane potential and action potentials

• Resting membrane of -70mv

• Threshold is -55 mv: all or nothing response

  • Resting membrane potential: both Na+ and K+ voltage gated channels are closed- only leakage channels are open

  • Depolarization: Na+ channels open and the cell becomes more positive as Na+ rushes in

  • repolarization: Na+ channels start to close as K+ channels open and K+ rushes out of the cell

  • hyper polarization: Na+ channels reset and OK+ channels start to reset

Refractory periods:

• Absolute refractory: period when action potential is depolarizing and repolarizing; no matter how great the stimulus is, it can not trigger another action potential during this period

• Relative refractory: period when action potential is hyper polarizing; need a larger then normal stimulus in order to trigger another action potential

Graded potentials and action potentials

• Graded potentials: localized changes in membrane potential

• small intensity, takes many graded potentials to respond to a stimulus, frequency, must be propagated, located on the dendrites and soma, triggered when a change in stimulus to the neurons environment open ion gates channels

Propagation of action potentials, stimulus intensity

• Action potential must be propagated down an axon

• Stimulus intensity: coded by the frequency of action potentials

  • More action potentials, the stronger the stimulus

Conduction velocity:

• Axon diameter: larger the diameter, faster the action potential conducts

• Degree of myelin

• Unmyleinated w myelinated axon

  • Unmyleinated: domino effect, slower, takes a while for ions to diffuse across the membrane, which is what makes it slower

  • myleinated: saltatory conduction: reduces the number of diffusions across the membrane, which makes the propagation faster

Fiber classification

• Type A: larger fibers, fast, myelinated, 4 neural pathways

• Type B: kind of fast, lightly myelinated, found in autonomic nervous system, intermediate diameter

• Type C: unmyleinated, slow, small diameter, autonomic nervous system

9/14/2026

Synapses and chemical signaling between presynaptic and postsynaptic neurons

• Electrical signaling: includes gap junctions to connect adjacent cells, small molecules move from one cell to the next

• Chemical signaling: involved neurotransmitters

  • Na+ channels on pre synaptic neuron, Na+ rushs in

  • Ca+ channels on button allow Ca+ in, which triggers exocytosis of neurotransmitter into the synaptic cleft

  • Neurotransmitters bind to receptors on the post-synaptic neuron

  • This causes graded potentials onj the post synaptic neuron

  • To stop the process, neurotransmitters can diffuse out of the synaptic cleft, enzymes can kill neurotransmitters, or reuptake

Post synaptic potentials

• EPSP: excitatory; depolarizing graded potentials, influx of Na+ ions

• ISPS: inhibitory; hyper polarizing graded potentials, efflux of K+

Summation and integration

• No summation: 1 EPSP fires, and another fires to long after that one, causing no change in membrane potential

• Temporal summation: 1 EPSP fires onto a dendrite and another fires right after on the same dendrite, causing a change in membrane potential, only need 1 PRESYNAPTIC neuron

• Spatial summation: 1 EPSP fires on one dendrite, and another EPSP fires on another dendrite, causing a change in membrane potential, need MORE THAN 1 PRESYNAPTIC NEURON

• Spatial summation of EPSP and IPSP: an ESPS and IPSP fire onto the post-synaptic neuron, which causes them to cancel out

Neurotransmitters

• Ach: most abundant in body

  • Inhibitory or excitatory

    • nictonine: excitatory, fast, direct, skeletal muscles- all excitatory ate ligand gated channels

    • Muscatine: slow, indirect, inhibitory or excitatory, controls pacemaker of heart

• Norep

  • Inhibitory or excitatory

  • Indirect

  • Inhibits the GI system

  • Associated with depression

Neurotransmitters receptors

• Two types: ligand gated channels and second messenger system

• Ligand gated channels: influx of Na+, can be inhibitory or excitatory, allows specific ions to cross membrane

• Second messenger system

  • Ligand binds to receptor, activating G-proteins that use GDP, binds to adenylate cyclase, uses ATP to activate cAMP

Neural pools

• Parallel: parallel to each other: info going 2 separate places

• Diverging: one pre-synaptic neuron synapses onto 2 different post-synaptic neurons

• converging: 2 pre-synaptic neurons synapses onto 1 post-synaptic neuron

• Reverberating circuit: same neuron synapses again: used to breath without thinking about it