Topic 1.2 & 1.3: Overview of the Nervous System, Neuron and Neural Firing

• The endocrine system:

  the endocrine system is connected to your nervous system

  • it secretes chemical messages through your blood stream called hormones

  • it is the body’s slow chemical communication system, which consists of glands that secrete hormones

    • Hormones: All Loving Grandmas Make Oatmeal

      • Adrenaline: Action (fight or flight): produced from the adrenal glands located above the kidneys

      • Leptin: Lose appetite (full stomach): produced from fat cells

      • Ghrelin: Growing belly (hungry): produced from the stomach

      • Melatonin: Midnight (sleepy): produced from the pineal glands

      • Oxytocin: Open hearts (love): produced from the pituitary glands.

    • Major Endocrine Glands:

      • Pituitary gland: known as the (“master gland”)

        located in the brain and controlled by the hypothalamus

        regulates other endocrine glands and produces hormones like growth hormone and oxytocin.

      • Adrenal gland:

        located above the kidneys

        secrete hormones like adrenaline, norepinephrine, and cortisol (which help the body respond to stress)

        it is connected to the autonomic nervous system that controls involuntary responses

      • Pancreas:

        Releases insulin, a hormone that regulates blood sugar..

      • Ovaries:

        secrete female sex hormones like estrogen and progesterone which are crucial for female sexual development and functioning

      • Testes:

        secrete male sex hormones like testosterone, which are crucial for male sexual development and functioning

    • Hypothalamus:

      a region in the brain that links the nervous system and endocrine system by controlling the pituitary gland.

      • during normal circumstances, it works with the parasympathetic nervous system to sustain homeostasis and normal functioning.

      • during stressful conditions, it activates the sympathetic nervous system, initiating the stress response

    • Feedback Loop System:

      Nervous system and endocrine system work together to maintain homeostasis

      • Brain > pituitary gland > other glands > hormones > body & brain.

      The nervous system directs endocrine secretions, which then influence the nervous system in a continuous feedback loop.

Nervous system:

The nervous system uses electrochemical messages. > faster than the endocrine system

Nerve cells: neurons (Sensory neurons, Interneurons, Motor neurons)

Central Nervous System (CNS)

The brain + the spinal cord

The spinal cord connects the brain to the rest of the body.

The sensory neurons go up the spinal cord and the motor neurons go down the spinal cord.

Peripheral Nervous System (PNS)

Made of thick bundles of axons called nerves that carry out messages back and forth between the CNS and the rest of the body.

• Somatic nervous system:

  controls skeletal muscles

  voluntary movement

• Autonomic nervous system:

  automatic

  involuntary

  wants to sustain homeostasis

  • Sympathetic: arouses you

    FIGHT OR FLIGHT

  • Parasympathetic: calms you down

    REST AND DIGEST

Types of Neurotransmitters