BIOPSYCHOLOGY Flashcards
Central nervous system
The central nervous system is made up of the brain and spinal cord and has two main functions, the control of physical movement and regulation of homeostatic function. The brain receives information via the sense organs and sends messages to the body using nerve cells in the spine.
Peripheral nervous system
The peripheral nervous system is comprised of all of the nerves outside of the CNS. The function of this part of the nervous system is to relay nerve impulses from the CNS (the brain and spinal cord) to the rest of the body and from the body back to the CNS. Peripheral nerves are throughout the body, and allow us to sense the world around us. The function of this part of the nervous system is to relay nerve impulses from the CNS (the brain and spinal cord) to the rest of the body and from the body back to the CNS.
The peripheral nervous system contains the autonomic and somatic nervous system.
Brain
The brain is the centre of all conscious awareness. The brain’s outer layer is the cerebral cortex and its only 3mm thick and is only found in mammals. The brain is divided into two hemispheres.
Spinal cord
The spinal cord is an extension of the brain. It passes messages to and from the brain and connects nerves to the peripheral nervous system. It is also responsible for reflex actions.
Autonomic nervous system
The autonomic nervous system governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses. The autonomic system regulates involuntary actions.
The autonomic nervous system transmits information to and from internal bodily organs. It is ‘autonomic’ because the system operates involuntarily . It has two main divisions: the sympathetic and parasympathetic nervous system.
Somatic nervous system
The somatic nervous system governs muscle movement and receives information from sensory receptors. The somatic nervous system regulates voluntary actions.
The somatic nervous system transmits information from receptor cells in the sense organs to the CNS. It also receives information from the CNS that directs muscles to act.
Sympathetic nervous system
The sympathetic nervous system pushes an individual into action when faced with an emergency. The SNS causes the heart to beat faster and the blood pressure to increase. The SNS is primarily involved in responses that help us to deal with emergencies (fight or flight) such as increasing heart rate and blood pressure and dilating blood vessels in the muscles. Neurons from the SNS travel to virtually every organ and gland within the body, preparing the body for the rapid action necessary when the individual is under threat. E.g The SNS causes the body to release stored energy, dilate pupils and hair to stand on end. It slows bodily processes that are less important in emergencies such as digestion and urination.
Parasympathetic nervous system
The parasympathetic nervous system relaxes them after an emergency has passed. The PNS reduces blood pressure and slows the heartbeat down. Another benefit is that digestion will begin again under PNS influence . This is because the PNS is involved with energy, conservation and digestion, it’s sometimes referred to as the body’s rest and digest system.
Thyroxine
The thyroid gland releases thyroxine which is responsible for regulating metabolism.
ACTH (adrenocor-
ticotropic hormone)
The pituitary gland stimulates the adrenal cortex and the release of cortisol during the stress response.
Cortisol
The adrenal cortex releases cortisol, which stimulates the release of glucose to provide the body with energy while supressing the immune system.
Oestrogen
Oestrogen is produced in the ovaries and is responsible for the development of secondary female characteristics and controls the regulation of the reproductive system, including the menstrual cycle and pregnancy.
Testosterone
Testosterone is produced in the testes and is responsible for the development of secondary male sex characteristics during puberty, while also promoting muscle growth.
Adrenaline
The stress hormone adrenaline is released from the adrenal medulla into the bloodstream. Adrenaline triggers physiological changes which creates the physiological arousal in the body necessary for the fight or flight response.
Inhibition
Some neurotransmitters act by making the postsynaptic neuron more negatively charged so that they are less likely to fire. This is because there is an inhibitory postsynaptic potential. This is an inhibitory effect. This is the case for serotonin. It has a calming, relaxing effect by slowing things down.
