the nervous system- biopsychology Flashcards
what is the nervous system
specialised network of cells in human body amd our primary internal communication system
based on electrical and chemical signals
what are the functions of nervous sytem
to collect process and respond to info in environment
coordinate working of different organs and cells in body
what is the central nervous system
made up of brain and spinal cord
brain is centre of all conscious awareness, brains outer layer cerebral cortex only 3mm thick and covers brain, only found in mammals, brain highly developed in humans and is what distinguishes higher mental functions from those of other animals, divided into two hemisoheres
spinal cord is extension of brain, passes messages to and from the brain and connects nerves to PNS, responsible for reflex actions
what is the peripheral nervous system
transmits messgaes via millions of neurons to and from central nervous system
subdivided into autonomic nervous system which governs vital function in the body such as breathing heart rate digestion sexual arousal and stress responses and the somatic nervous system which governs muscle movement and receives information from sensory receptors
what are glands and hormones
endocrine acts more slowly than nervous system but have widespread and powerful effects
various glands produce hormones secreted into bloodstream and affect any cell in the body that has a receptor for particular hormone
hormones affect cells in more than one body organ leading to diverse and powerful responses- thyroxine affects cells in the heart increases the heart rate affects cells throughout the body increasing metabolic rates and growth rates
pituitary gland located in brain controls the release of hormones from other enocrine glands in the body
main glands- hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, testes
how does endocrine and ans work together
during stressful event
stressor perceived, part of brain called hypothalamus activates pituitary gland and triggers activity in the sympathetic branch of automatic nervous system, ans changes from normal resting state (parasympathetic state) to the physiologically aroused sympathetic state
what is adrenaline
released from adrenal medulla into bloodstream
adrenaline triggers physiological changes in the body such as increased heart heart which creates physiological arousal necessary for fight or flight response
what is immediate and automatic
all happens in an instant as soon as threat is detected, acute response and an automatic reaction in the body, changes explain why stress panic experienced as a sick feeling
what is parasympathetic action
once threat passed, parasympathetic nervous system returns body to resting state, parasympathetic branch of ans works in opposition to sympathetic nervous system- actions antagonistic to sympathetic system
acts as a brake and reduces activies of body that were increased by actions of sympathetic branch- rest and digest response
what are the physiological changes in the sympathetic state and parasympathetic
increases heart rate, increases breathing rate, dilates pupils, inhibits digestion, inhibits saliva production, contracts rectum
decreases heart rate, decreases breathing rate, constricts pupils, stimulates digestion, stimulates saliva production, relaxes rectum
