Psych Brain 1B

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