The nervous/endocrine system Flashcards
The nervous system
Specialised network of cells
Primary internal communication system
Based on electrical/chemical signals
2 main functions of nervous system
Collect/process/respond to info in environment
Co-ordinate the working of different organs/cells in the body
Nervous system subsystems
Central (CNS)
Peripheral (PNS)
Central nervous system (CNS)
Brain/spinal chord
The brain (CNS)
Centre of all conscious awareness
-Surrounded by cerebral cortex
-Highly developed in humans
-2 hemispheres
The spinal chord (CNS)
Extension of brain
-Passes messages to and from brain/connects to PNS
-Reflex actions (e.g pulling hand away from volcano)
Peripheral nervous system (PNS)
Transmits messages to and from CNS
Autonomic nervous system (ANS)
Somatic nervous system (SNS)
Autonomic nervous system (PNS)
Governs vital functions in body (e,g breathing)
Somatic nervous system (PNS)
Governs muscle movement/receives info from sensory receptors
Endocrine system
Based on hormones secreted form glands
Example of hormone that affects cells in more than 1 body organ
Thyroxine
-Secreted from thyroid= affects heart cells (+ heart rate)/other cells in body (+ metabolic rate)
Key endocrine gland
Pituitary gland
-Controls release of hormones from all other endocrine glands
How does the Endocrine/ANS work together
Stressor perceived= hypothalamus activates pituitary gland
=Triggers activity in ANS
=ANS changes from resting state (parasympathetic) to aroused (sympathetic)
=Adrenaline released= physiological arousal for fight or flight response
How long does fight or flight take?
Happens in an instant
(immediate and automatic)
Example of physiological changes during fight or flight
increased heart-rate/butterflies in stomach
