NERVOUS SYSTEM:
The nervous system has two main functions:
1) To collect, process and respond to
information in the environment.
2) To coordinate different organs and cells in
the body.
CENTRAL NERVOUS SYSTEM (CNS)
Made up of the brain and spinal cord.
Controls behaviour and regulates physiological
processes.
Brain Spinal cord
● The centre of conscious awareness. ● Extension of the brain (responsible for all reflex
● Has 4 main areas (cerebellum, cerebrum, diencephalon actions).
and brain stem). ● Passes messages to and from the brain and
● Has two hemispheres. connects nerves to the PNS.
PERIPHERAL NERVOUS SYSTEM (PNS)
Transmits messages, via neurons to and from the nervous system.
Divided into the Autonomic Nervous System (ANS) and the Somatic Nervous System (SNS).
Autonomic Nervous System (ANS)
● Governs vital functions in the body such as breathing, heart rate, digestion etc
○ Sympathetic NS - controls fight/flight, noradrenaline the main neurotransmitter,
increases heart rate, dilates vessels and pupils, slows non-emergency processes.
○ Parasympathetic NS - rest and digest, acetylcholine main neurotransmitter, which
slows what noradrenaline increases and restores digestive processes to normal
Somatic Nervous System (SNS)
● Governs muscle memory and receives info from sensory receptors.
ENDOCRINE SYSTEM:
The endocrine system works with the nervous system to control vital functions in the body through
the action of hormones.
Glands:
Organs in the body that produce hormones (i.e pituitary gland which is often called the ‘master
gland’ because it controls the release of hormones from all the other glands)
Hormones:
Hormones are secreted in the bloodstream and affect any cell in the body that has a receptor. (i.e
thyroxine which is produced by the thyroid gland which increases metabolic rates.)
, Gland Hormone Responsibility
Hypothalamus N/A Connected to the pituitary gland, stimulates and controls the
release of all hormones.
Pituitary gland Oxytocin ‘Master gland’ controls all other glands
ACTH
Thyroid gland Thyroxine Regulates metabolism
Parathyroid gland Parathormone Increases calcium in the blood.
Pancreas Insulin Absorption of glucose from the blood into fat, liver and skeletal
muscle cells.
Adrenal gland Adrenaline/noradrenaline Reaction to flight/fight
Ovaries Oestrogen/Progesterone Development of female reproductive system and secondary sexual
characteristics.
Testes Testosterone Development of the male reproductive system. Promotes secondary
sexual characteristics e.g growth of body hair.
Pineal gland Melatonin Regulates the sleep-wake cycle
FIGHT OR FLIGHT WITH THE ENDOCRINE SYSTEM AND AUTONOMIC NERVOUS
SYSTEM:
The fight or flight response becomes activated when an individual enters a stressful or dangerous
situation.
1) Stressor perceived by the hypothalamus which activates the pituitary.
2) This arouses the sympathetic nervous system.
3) Adrenaline is released into the bloodstream which causes changes in the body (increased
heart rate, dilation of pupils etc).
4) Immediate and automatic response
5) Parasympathetic nervous system is triggered (rest and digest), which returns the body into
a resting state.
+Research has challenged ‘tend and befriend’. -temporal validity. -Beta bias response is -Gray argues that the first reaction is not to
Acute stress can lead to more cooperative Less of a survival different in females than flee but to freeze.
behaviour - 9/11. mechanism in modern day males. Most animals show a freeze response, where
Humans are fundamentally social animals and life. Less biologically Studied by Taylor et al who they are hypervigilant.
it is their protective nature that has an stressing response needed. found women show ‘tend and Focuses attention and finds the best
evolutionary advantage. Fight/flight can have befriend’. Women have diff response.
negative consequences such response because of innate
as high blood pressure. primary caregiver instincts.
Fight/flight = maladaptive Decreases validity of the
response. fight/flight response.
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