Nervous system Flashcards
Nervous system
Specialised network of cells and our primary communication system
Two main functions of the nervous system
To collect, process and respond to info in the environment
To coordinate the working of different organs and cells in the body
The nervous system is divided into subsystems, what are they?
Central nervous system (CNS)
Peripheral nervous system (PNS)
What is the CNS and PNS made up of
CNS - brain and spinal cord
PNS - nerves
Function of the brain in CNS
The brain, a highly developed outer layer, is the centre of conscious awareness, divided into two hemispheres, distinguishing humans from animals
Function of the spinal cord in CNS
It is an extension of the brain and is responsible for reflex actions
It passes messages to and from the brain and connects nerves to the PNS
Function and structure of the PNS
PNS transmits messages, via millions of neurons to and from the nervous system
It is further divided into:
Autonomic nervous system (ANS)
Somatic nervous system (SNS)
Function of the autonomic nervous system
Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses
Function of the somatic nervous system
Governs muscle movement and receives info from sensory receptors
What is the somatic nervous system divided into?
Give examples for each
Sympathetic state - increase heart rate, increase breathing rate, dilates pupils, inhibits digestion/saliva production, contracts rectum
Parasympathetic state - decrease heart rate, decrease breathing rate, constricts pupils, stimulates digestion/saliva production, relaxes rectum
Key features of the endocrine system
Works alongside the nervous system to control vital functions in the body through the action of hormones
It works more slowly than the nervous system
Endocrine system: Hormones
Hormones are secreted in the bloodstream and affect any cell in the body that has a receptor for that particular hormone
e.g insulin regulates blood sugar levels
Endocrine system: Glands
Glands are organs in the body that produce hormones
Key gland: pituitary gland (located in the brain), the master gland as it controls the release of hormones from all the other endocrine glands in the body
The endocrine system and the ANS work together e.g flight or fight response, how? (4 points)
ANS changes from a parasympathetic state to sympathetic state
The pituitary gland releases Adrenocorticotropic hormone (ACTH)
This effects cells on the adrenal gland, causing them to release adrenaline into the bloodstream
This creates psychological arousal, necessary for fight or flight response
