Unit 1B Final

Nervous System

• Our neurons communicating via neurotransmitters make up or body's nervous system

  • Our speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral nervous system and central nervous system 

    • Peripheral nervous system (PNS)- the sensory and motor neurons that connect the central nervous system to the rest of the body

      • Two unique components

        • Somatic nervous system- voluntary control of our skeletal muscles

          • Heavily involved with our sensory neurons and motor neurons

        • Autonomic nervous system- controls our glands and our internal organ muscles- self regulating 

          • Sympathetic nervous system-

            • Division of the autonomic nervous system that arouses the body, mobilizes its energy

            • Can alarm or challenge us-elevate our heart rate, slow digestion, raise blood pressure and sugar,- make us ready for action

          • Parasympathetic nervous system- 

            • Division of the autonomic system that calms the body, conserving its energy

            • Produces opposite effects  of the sympathetic so that our body returns to homeostasis

    • Central nervous system (CNS)- the brain and spinal cord

      • Brain- thinking , feeling, and acting; our humanity- tens of billions of neurons

        • Anatomical structure that resides in ou skull that performs numerous physiological functions and contains our mind the root of many psychological phenomena

        • Weighs approximately 3 lbs

        • There are multiple “levels” of your brain with varying complexity with different parts that each perform different functions 

          • Cerebral Cortex- outermost layer of the brain- what we see when we look at a brain

            • Contains 20 billion nerve cells and 300 trillion synaptic connections

            • Divided into 2 halves called hemispheres

              • The left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body

            • We divide each hemisphere up into smaller sections called lobes that are separated by fissures (folds)

              • Frontal lobe

                • Front of cerebral cortex (behind forehead)

                • Involved in speaking, muscle movement, planning, problem solving, critical thinking, and judgements

                • Contains motor cortex- located at the rear end of the frontal lobe and controls voluntary movements 

                • Prefrontal cortex- recall and remember events from the past

                • Frontal association area- mostly deals with personality and forming thoughts and ideas

              • Parietal lobe

                • Middle of cerebral cortex, behind front lobe

                • Contains the somatosensory cortex- controls all sensational feeling in the body (works hand in hand with the frontal lobe’s motor strip)

              • Occipital lobe

                • Back of the brain

                • Processes and makes sense of the things we see

                • Creates images or visuals that we can understand- even when it is a topic we do not know (heffalump)

              • Temporal lobe

                • Side of our head, where the temple is

                • Hearing and spoken language

                • A special part of the temporal lobe is used to create sentences- coherent

                • Talking to yourself in your head

            • Brain Stem- heart of the brain that connects spinal cord and brain 

              • Pons- upper part, movement and controlling sleep (works with motor cortex)

              • Medulla- lower part, breathing and heartbeat SOMETHING ANOU SLEPP?

        • Left hemisphere

          • The Old Brain

            • Thalamus- atop brain stem; sensory control center

              • Information comes in and out of the brain through the thalamus 

            • Cerebellum- latin for “little brain”

              • Hang off brain stem- responsible for involuntary functions

              • Process sensory input enables non verbal learning and memory

              • movement and balance

          • Reticular formation

            • Reticula means “netlike”

            • Neuron network extending form the spinal cord up though the thalamus

            • Allows for multitasking by relaying sensory stimuli to other parts of the brain (helps thalamus)

            • Arousal and alertness

          • Limbic System

            • Lower brain system perform most of their functions involuntary but the limbic system is slightly more voluntary

            • Sits between the old brain structures and newer brain structures

            • Consists of the amygdala, hypothalamus, and the hippocampus

              • Amygdala- size of lima bean

                • Fear, anger, anxiety, and stress (not the only factor though/part of the brain)

              • Hypothalamus- bodily functions and maintenance

                • Hunger, thirst, body temperature, sexual behavior

                • Control pituitary gland- makes things happen by sending messages to other parts of the body and glands

                • Aims for homeostasis (not always thirsty or always hungry)

              • Hippocampus- memory

                • Processes our conscious and explicit memories 

                • Hippocampus shrinks with age decreasing its function and making it hard to remember things, especially new things

                • Can be damaged in brain injuries like concussions

• Spinal cord- two way informations highway connecting our peripheral with our brain

  • Reflexes- simple, automatic response to a sensory stimulus

Endocrine System

• The body's “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream (secondary)

  • Hormones- chemical messengers that are manufactured by glands in out endocrine system, travel through our body, and affect other tissues

    • Influence a wide array of areas- food, aggression, sex

      • Thyroid- affects our metabolism (life sustaining processes such as food conversion into energy)

      • Parathyroid- helps regulate the level of calcium in our blood

      • Pancreas- regulates the level of sugar in our blood

      • Pineal gland- releases melatonin- involved in sleep cycles

      • Ovaries- secretes female sex hormones- involved in reproduction

      • Testes- secretes male sex hormones- involved in reproduction

  • Our endocrine system works hand in hand with the nervous system to make sure all of the messages travel throughout our body

  • Hormones travel at a much slower rate than messages along neurons 

• Variety of glands perform various functions that affect our body

  • Adrenal Glands

    • Sit above our kidneys and release hormones that help arouse the body in times of stress

    • Increase heart rate, blood pressure, and blood sugar with surge of energy or give us a fight-or-flight response

    • The feeling the hormones provide will last after the sensation has passed

  • Pituitary Gland

    • Pea-sized gland located in the brain off of our hypothalamus (controlled by this)

    • Known as the master gland- releases a variety of hormones and helps control other glands

      • Human Growth Hormone- involved in our physical development

      • Oxytocin- involved in reproduction and sexual arousal; supports bonding, group cohesion, and trust

Types of Neural Messaging

• Our mental activity is constantly emitting electrical, metabolic, and magnetics signals that allow observation of our brain to work

  • Electroencephalogram (EEG)- an amplified recording of the waves of electrical activity sweeping across the brain's surface. These waves are measured by electrodes placed on the scalp; can also be used to evaluate nerve movement

  • Magnetoencephalography (MEG)- a brain imaging technique that measures magnetic fields from the brain’s natural electric activity

  • Computed Tomography Scan (CT Scan)- a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure

  • Positron Emission Tomography (PET Scan)- a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given ask

  • Magnetic Resonance Imaging (MRI)- a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRIs show brain anatomy

  • Functional MRI (fMRI)- a technique for revealing blood flow and therefore brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure

Sleep and Dreams

• Misconceptions about sleep

  • When people dream of performing some activity, their limbs move in concert with the dream

  • Older adults sleep more than younger adults

  • Sleepwalkers act out their dreams

  • Some people dream every night and some rarely

  • Experts recommend insomnia be treated with occasional sleeping pills

• Sleep- periodic natural loss of consciousness- distinct from unconsciousness resulting from coma, general anesthesia, or hibernation

  • Our bodies function on a 24 hour cycle of the day because of our internal biological clock called circadian rhythm

    • Tied to wakefulness and body temperature

  • Teenagers and young adults- more energized in the evening, “night owls”

  • As you get older we transition to morning-loving “traits”

    • Morning types typically tend to do better in school, take more initiative, be more punctual, and be less vulnerable to depression 

  • Every 90 minutes we are asleep we cycle through distinct stages

    • REM Sleep- rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur, our muscles relax while bod systems are still activated

      • Alpha waves- relatively slow brain waves of a relaxed, awake state- show up as we begin to fall asleep

      • As we become comfortable in our surroundings, we will transition to NREM Sleep- non-REM sleep which encompasses all sleep stages except REM Sleep (slower breathing and irregular brain waves)

        • NREM-1- may cause hypnagogic sensations- bizarre experiences, such as jerking or a feeling of falling or floating weightlessly

        • NREM-2- can contain bursts of rapid, rhythmic brain wave activity called sleep spindles (20 mins)

        • NREM-3- 30 minutes with delta waves- large slow brain waves associated with deep sleep

          • We then transition back into NREM-2 before entering REM sleep- which will increase in length as the night goes on

  • Why do we sleep? Protection, recuperates, resort and rebuild our fading memories of the days experiences, creative thinking, growth 

    • 15 yes or no questions about whether or not you get enough sleep

  • Sleep Deprivation and Disorders

    • Effects of not getting enough sleep

      • Decreased

        • Ability to focus

        • Ability to store memories

        • Metabolic rate

        • Production of immune cells

        • Muscle strength

        • Reaction times

      • Increased

        • Risk of depression

        • Production of fat cells

        • Inflammation and arthritis

        • Risk of high blood pressure

    • Disorders

      • Insomnia- recurring problems in falling or staying asleep

      • Narcolepsy- a sleep disorder characterized by uncontrollable sleep attacks where the sufferer may lapse directly into REM sleep, often at inappropriate times

      • Sleep apnea- characterized by temporary cessation of breathing during sleep and repeated momentary awakenings

      • Sleepwalking and sleeptalking- doing normal walking activities while asleep; sleep talking can happen at any stage while sleepwalking is NREM-3

      • Night terrors- characterized by high arousal and an appearance of being terrified and seldom remembered (unlike nightmares) 

• Dreams- a sequence of images, emotions, and thoughts passing through a sleeping person’s mind

  • Can appear to be very real experiences for us; reflective of our lives

    • Trauma in our lives or in the world can cause us to dream about trauma

    • The type of media we consume can impact the types of dreams we have

    • 8/10 dreams are marked as negative

    • 1/10 dreams for males are sexual in nature

    • 1/30 dreams for females are sexual in nature

  • Dream Theories- ultimately, dreams are a mystery, it's possible that none of these are true

    • Freud’s Wish-Fulfillment- dreams provide a psychic safety valve

      • express otherwise unacceptable feeling, manifest content (remember), latent content (hidden meaning)

    • Information-Processing- dreams help us sort out the day’s events and consolidate and form our memories

    • Physiological Function Theory- regular brain stimulation from REM sleep may help develop and preserve neural pathways

    • Activation Synthesis- REM sleep triggers neural activity that evokes random visual memories, which our sleeping brain weaves into stories

Cognitive Development- dream continent reflects dreamers’ level of cognitive development- their knowledge and understanding. Dreams stimulate our lives, including worse-case scenarios