biopsychology

Neuron

Cells within the nervous system that process and transmit messages through electrical and chemical signals

Sensory neurons

These carry nerve impulses (messages) from the PNS to the CNS (brain and spinal cord). When the nerve impulse reach the brain they are translated into 'sensations' such as vision, taste, touch.

They have long dendrites and short axons

Relay neurons

These connect the sensory neurons to the motor neurons or other relay neurons to allow them to communicate. They have short dendrites and short axons.

Motor neurons

These connect the CNS to effectors such as muscles and glands to control muscle movements by releasing neurotransmitters that bind to the receptors on muscles to trigger a response, which leads to movements.

They have short dendrites and long axons.

Cell body (soma)

Includes a nucleus which contains the genetic material of the cell

Nodes of ranvier

Gaps in the myelin sheath - the electrical impulses speeds up transmissions down the axon by forcing it to jump across these gaps

Dendrites

Branch like structures which protrude from the cell body and carry imposes from other neurons towards the cell body

Axon

Carries impulses away from the cell body, down the length if the neuron

Myelin sheath

A layer of fat which covers the axon, protecting it and speeding up the transmission of the electrical impulse

Synaptic transmission

The process by which neurons communicate with each other by sending chemical messages across the synapse which separates them

Excitation

When a neurotransmitter increases the positive charge of the post synaptic neuron - increasing the likelihood that the neuron will pass an electric impulse

Inhibition

When a neurotransmitter, such as serotonin, increases the negative charge of the post synaptic neuron. This decreases the likelihood that the post synaptic neuron will pass on the electrical impulse.

Summation

Net/ overall of the post synaptic neuron. This determines whether an electrical impulse will be passed on.

Nervous system (NS)

A network of cells that transmit electrical signals to different parts of the body, allowing communication to take place. it consisted of the central nervous system and the peripheral nervous system

Central nervous system (CNS)

Consists of the brain and spinal cord and is the origin box complex decisions and cognitive processes

Brain

Centre of all complex decisions and cognitive processes

Spinal cord

Passes messages to and from the brain and body

Peripheral nervous system (PNS)

A connection of nerve cells / neurons that sends information to the CNS from the outside world and transmits messages from the brain and spinal cord to the muscles and glands.

Somatic nervous system (SNS)

Controls voluntary movement, by transmitting information from receptor cells in the sense organs to the CNS using sensory neurons, and receiving information from the CNS that directs muscles to act using motor neurons.

Autonomic nervous system (ANS)

Controls involuntary processes, by transmitting information to and from internal bodily organs

Sympathetic (fight or flight)

Neurons connect to glands and organs and adrenaline secreted increases the heart rate and blood pressure

Parasympathetic

Returns body to retiring state after the flight or fight response

Endocrine system

A network of glands across the body that secretes chemical messages called hormones. This system uses blood vessels to transmit information. Different hormones produce different effects (behaviours)

Gland

An organ in the body which synthesises substances such as hormones

Hormone

Chemical substances which circulate in the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly

Fight or flight response

The way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor, or in some cases, flee

Adrenaline

A hormone produced by the adrenal glands which is pat of the human body's immediate stress response system. Adrenaline has strong effect on the cells of the cardiovascular system - stimulating heart rate, contracting blood vessels and dilating passages

Pituitary gland (master gland)

• Stimulates the release of hormones from other glands

• Secretes ACTH: stimulates adrenal cortex and the release of cortisol during the stress response

Posterior lobe

Secretes oxytocin: responsible for uterus contractions during childbirth

Hypothalamus

Stimulates and controls the release of hormones from the pituitary gland

Pineal gland

Secretes melatonin: responsible for important biological rhythms, including the sleep wake cycle

Thyroid gland

Secretes thyroxine: responsible for regulating metabolism

Adrenal gland

• Adrenal medulla secretes adrenaline and no adrenaline: key hormones for the fight or flight response

• Adrenal cortex secretes cortisol: stimulates the release of glucose to provide the body with energy, while suppressing the immune system

Ovaries

Secretes oestrogen: controls the regulation of the female reproductive system, including the menstrual cycle and puberty

Testes

Secretes testosterone: responsible for the development of the male sex characteristics during puberty, as well as promoting muscle growth

Pancreas

Secretes insulin: increases blood glucose levels

Thymus

Responsible for the production and maturation of immune cells, in lymph cells