Biopsychology

Nervous system

Divisions

Human nervous system = complex network of nerve cells that carry messages from and to the brain and spinal cord to different parts of the body

Central nervous system (CNS) = includes the brain and spinal cord where they receive and transmit information

Divided into 2 main systems: 1. CNS 2. PNS

Peripheral nervous system (PNS) = sends information to the CNS from the outside world then transmits messages from the CNS to muscles and glands in the body

Somatic nervous system (SNS) = transmits information from receptor cells in the sense organs to the CNS (also gets info from CNS that directs muscles to act). VOLUNTARY

Autonomic nervous system (ANS) = transmits information to and from internal bodily organs & is divided into the sympathetic and parasympathetic nervous systems. INVOLUNTARY

Sympathetic system = INCREASES bodily activities. It's a network of nerves that helps body activate fight or flight response (symptoms: increased heart/sweat/breathing rates and dialated pupils)

Parasympathetic system = DECREASES bodily activities. Activates in rest and digest conditions and conserving energy for the body to use later (symptoms: decreased heart/sweat/breathing rates and constricts pupils)

Homeostasis is usually maintained by a balance between the sympathetic and parasympathetic symptoms

Endocrine System

It's a collection of glands that regulate bodily functions and acts by releasing chemical messengers (hormones) into the blood

The glands + hormones + effect

Pituitary gland which is the master gland it produces the hormone ACTH this controls the release of hormones from other glands

Hypothalamus with produces the hormone CRH which links nervous system to the endocrine system

Pineal Gland produces the hormone Melatonin which modulates sleep pattern, keeping the body to a day/night rhythm

Thyroid gland produces thyroxine which modulates metabolism

Thymus which produces thymosin which stimulates the development of T cells in the immune system

Pancreas produces insulin which regulates blood sugar levels

Adrenal gland produces adrenaline which regulates the effects of the fight or flight response

Ovaries produce oestrogen which develops secondary sexual characteristics in females

Testicles produce testosterone which leads to the development of secondary sexual characteristics in males

Neurons

Sensory

Relay

Motor

Neurons transmit signals electrically and chemically

Detects stimulus at sensory receptors, action potential travels across the nerve passing along the myelinated axon, the electrical signal is converted into a chemical signal to cross the synapse

After synaptic transmission a new action potential forms in the dendrites, this neurone is in the spine and sends a signal to the CNS but also immediately sends a signal along its axon to the motor neurone

Detects the signal from the relay neurone via synaptic transmission and passes the signal along its own myelinated axon to simulate an effector