Biopsychology: Year 13 content

• The nervous system: consists of 2 divisions the CNS and PNS that communicate using electrical signals
• Central nervous system: brain and spinal cord, controls voluntary and involuntary actions, behaviour and consciousness
• spinal cord: an extension of the brain that connects the CNS to the PNS and is responsible for reflex actions
• the brain: the centre of all conscious awareness. the outer layer is called the cerebral cortex that only mammals have. its split into 2 hemispheres, left and right
• the peripheral nervous system: the rest of the body containing the somatic and autonomic NS that send information from the outside world to the CNS and transmits messages from CNS back to the body
• somatic division: carries sensory info from receptors to the CNS and motor info from the CNS to effectors (muscles)
• autonomic division: regulates internal organs and unconscious processes and is split into sympathetic and parasympathetic NS
• sympathetic division: prepares us for fight or flight by increasing blood pressure, heart rate, respiration rate, pupil dilation and sweating
• parasympathetic division: slows down bodily functions and rests and digests by decreasing blood pressure and increasing digestion and salivary gland secretion
• the endocrine system: an information system in the body that instructs glands to release hormones directly into the blood stream
• hormones: chemical substances that travel in the bloodstream to target organs and produce a response
• pituitary gland: in the brain, a master gland, releases ACTH, controls how much hormones other glands release
• thyroid gland: located at base of neck, produces thyroxin which speeds up metabolism and growth
• adrenal glands: sit on top of kidneys, produce adrenalin which triggers fight or flight
• pancreas: behind stomach, produces insulin which regulates glucose levels in the bloodstream
• ovaries: female reproductive organ, produce oestrogen and progesterone, control egg release, puberty, sex drive
• testes: male reproductive organ, produce testosterone, control sperm production, puberty, sex drive
• stress: a biological and psychological response experienced on encountering a threat
• fight or flight: an animals response to an acute stress. the body becomes ready to fight or flee
• adrenaline: a hormone produced by the adrenal gland which is aprt of the human bodies immediate stress response
• flight or flight flow chart: 1. hypothalamus detects stressor 2. pituitary gland releases ACTH 3. adrenal gland releases adrenaline 4. the sympathetic state 5. fight or flight response is activated 6. the parasympathetic state is activated
• adrenaline and fight or flight causes: increased heart rate, breathing rate, pupil dilation, sweating, and decreases non essential functions
• motor neuron cell

  A) dendrites

  B) nucleus

  C) mylein sheath

  D) node of ranvier

  E) axon

  F) terminal button

  
• myelin sheath: insulates the axons so that electrical impulses can travel faster along it
• terminal buttons: endings of the motor neuron cells
• node of ranvier: gaps between the myelin sheath where there are no insulating layers speeding up the electrical impulse
• synapse: gap between two nerve cells
• action potential: the inside of a neuron is negatively charged and the outside is positive. when stimulated the charges swap. once the charge has been passed on it goes back to the resting state
• Synaptic transmission: the process of a nerve impulse being transmitted from one neuron to another
• Synaptic transmission process: presynaptic Neuron fires an action potential, which causes the release of vesicles containing neurotransmitters to fuse with the terminal button and release into the synapse. The postsynaptic neuron absorbs and it may trigger an action potential
• Types of neurotransmission: excitation and inhibition
• Excitation neurotransmission causes an increase in positive charge and transmission
• Inhibition transmission causes an increase in negative charge and a decrease in transmission
• types of neurones

  A) sensory

  B) relay

  C) motor

  D) long axon

  E) long cell body

  F) long dendrites