Nervous and endocrine system Flashcards
what is nervous system made up of
network of cells in human body, it’s our internal communication system
-collect,process and respond to information in the environment.
-coordinate working of different organs and cells in the body.
how is the human nervous system divided
human nervous system
-peripheral nervous system-
-somatic nervous system
-autonomic nervous system-sympathetic nervous system-parasympathetic nervous system
-central nervous system
-spinal cord
-brain
central nervous system
The brain is the centre of awareness. It is divided into two hemispheres. The cerebral cortex(outer layer) is more developed in humans than in all other animals.
-The spinal cord is an extension of the brain. It transports messages to and from the brain to the peripheral nervous system.
It is also responsible for reflexes.
the peripheral nervous system
The PNS transmits messages via neurons to and from the CNS
The somatic nervous system (SNS) receives information from the senses and transmits it to the
CNS. It also transmits information from the CNS to direct movement of muscles.
The autonomic nervous system is responsible for vital functions, such as heart rate, breathing, digestion, sexual arousal.
-Sympathetic nervous system
-parasympathetic nervous system
-needed for fight or flight response
the endocrine system
-work alongside the nervous system to control vital functions in the body.
-the endocrine system instructs various glands to release hormones into the blood
adrenal gland-adrenaline-getting our body ready for flight or fight
thyroid-thyroxine-increases heart rate/metabolic rate-affects growth rate
testicles-testosterone
ovaries-oestrogen
pineal gland-melatonin-start getting sleepy and then sleep when produced
Hormones affect any cells throughout the body that have receptors for that particular hormone.
This could in only in one particular organ, all throughout the entire body.
differences between the systems
endocrine-chemical messengers-long lasting effects-takes longer to work-more permanent and wide spread effects
nervous-electrical impulses-short lived effects- quick to work- temporary and localised response
systems working together
-The endocrine and ANS often work in parallel with one another, e.g. during a stressful event.
-When a stressor is perceived the hypothalamus triggers the sympathetic nervous system and the
ANS changes from its usual resting state to the sympathetic state.
-Adrenaline is released from the adrenal medulla into the bloodstream resulting in the physical arousal needed for fight / flight.
Once the threat has passed, the parasympathetic nervous system returns the body to its natural resting state.
sympathetic state
Increases heart rate
Increases breathing rate
Dilates pupils.
Inhibits digestion
Inhibits saliva production
Contracts rectum
