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Hypothalamus (Autonomic Nervous System (Parasympathetic (ganglions =…

- - - - more local response
  - - - increase concentration of glucose in blood
      - increase breathing capacity & rate –> more oxygen
      - raise arterial blood pressure to enhance delivery of glucose & oxygen to capillaries
      - shunt blood from skin & digestive tract to skeletal muscles
    - - leads to release of cortisol during "stress response"
        
        effects of cortisol
        
        releases glucose into bloodstream
        
        increases blood pressure for increased physical activtity – running/fighting
        
        stimulates brain for more intense awareness
        
        immune system activity = reduced to save energy for physical activity
      - HPA Axis
        
        (1) stress
        
        (2) parvocellular cells in hypothalamus secrete ACH to AP
        
        (3) AP releases ACTH into bloodstream
        
        (4) ACTH reaches adrenal gland causing them to release cortisol
        
        (5) after sufficient amount of cortisol negative feedback cause hypothalamus to stop releasing ACH
- - - - when the blood is filled with nutrients
      - energy is stored in 2 form
        
        glycogen in liver & skeletal muscle
        
        triglycerides in (fat)
    - - during fasting; between meals
      - stored glycogen & triglycerides are broken down to provide body w/ fuel
    - - rate of replenishing of energy reserves = rate of expenditure of energy reservees
        
        maintenance of body weight around set value
        
        restricted diet
        
        lose body fat
        
        after free access to food overeat until body fat restored
        
        force-fed
        
        gain fat mass
        
        after allowed to regulate own diet eat less until fat level return to normal
  - - - ob gene codes for leptin (protein) which is released by fat cells
      - leptin – hormone communicates w/ brain about fat reserves
        
        elevated levels in blood– activates hypothalamus & decreases feeding behavior
        
        decreased leptin level in blood– activates hypothalamus & increases feeding behaviors
        
        fuse ob-/ob- (lack both copies of gene) rat w/ normal mouse (share blood supply) –> normal feeding behavior
        
        proof communication from fat cells to brain = bloodborne (hormone)
        
        arcuate nucleus (hypothalamus)
        
        can sense leptin levels
        
        controls paraventricular nucleus & lateral hypothalamic area
        
        elevated leptin – neurons release anorectic peptide transmitters
        
        increase in alphaMSH & CART (peptide transmitters) –> inhibit feeding behavior (controlled by lateral hypo.)
        
        increase in metabolism (paravent. nucleus)
        
        increase in energy expenditure
        
        decreased leptin – neurons release orexigenic peptide transmitters
        
        increase in NPY AgRP (peptide transmitters) –> stimulate feeding behaviors (controlled by lateral hypo.)
        
        decrease metabolism (paravent. nucleus)
        
        decrease energy expenditure
  - - - core of each system has small set of neurons
      - neurons of diffuse systems arise from core
      - each neuron in core can influence many others
      - synapses can release transmitter into extracellular fluid & can diffuse to many neurons
    - - VTA
        
        opiate receptors & nAChRs
        
        stimulate DA release
      - nucleus accumbens
        
        cocaine receptors
        
        cocaine prolongs the action of DA & enhances DA actions
- - - - projection to parasympathetic & sympathetic neurons
    - - via anterior & posterior pituitary
    - - via connection w/ forebrain, limbic system, brainstem & spinal cord
- - - - release 2 hormones to posterior pituitary
        
        oxytocin
        
        uterine contractions (pitocin = given to induce labor)
        
        milk letdown reflex
        
        "love hormone"
        
        levels rise during sexual behavior
        
        promotes social bonding
        
        vasopressin
        
        antidiuretic hormone (ADH)
        
        regulates blood volume
        
        controls salt concentration
  - - - parvocellular cells secrete releasing hormone into AP
        
        causes AP to release hormones in bloodstream
        
        receptors for hypothalamic hormones cause anterior pituitary cells to release/stop releasing their hormones into blood