The nervous and endocrine systems Flashcards
What is the function of the nervous system?
Communication hub of the body- sends signals between neurons
What is the structure of the nervous system?
PNS and CNS
What is the function of the central nervous system?
Origin of all complex commands and decisions- receives, processes, and responds to sensory information
What is the structure of the CNS?
Brain and spinal cord
What is the function of the peripheral nervous system?
Transmits messages, via neurons, to and from the CNS
What is the structure of the PNS?
SNS and ANS (parasympathetic and sympathetic systems)
What is the function of the endocrine system?
Instructs glands to release hormones towards target organs
What is the structure of the endocrine system?
Glands (e.g: thyroid, pituitary) and hormones (thyroxine, adrenaline)
What is the function of the ANS?
Transmits info to and from internal organs- does so involuntarily and has 2 divisions
What is the function of the SNS?
Transmits info from the receptor cells to the CNS, and receives info from the CNS to muscles to cause action
What is the sympathetic state?
A state of fight or flight
What is the parasympathetic state?
A state of rest and digestion
What happens in the sympathetic state?
- Increases heart rate
- Increases breathing rate
- Dilates pupils
- Inhibits digestion
- Inhibits saliva production
- Contracts rectum
What happens in the parasympathetic state?
- Decreases heart rate
- Decreases breathing rate
- Constricts pupils
- Stimulates digestion
- Stimulates saliva production
- Relaxes rectum
What are glands?
Organs in the body that synthesise substances such as hormones
What are hormones?
Chemical substances that circulate in the bloodstream and only affect target organs
How is fight of flight triggered?
- Hypothalamus releases releasing hormone
- Pituitary gland releases stimulating hormone
- Adrenal gland releases adrenaline and cortisol
- Triggers sympathetic state in ANS
What is the function of the brain?
The centre of all conscious awareness
What is the function of the spinal cord?
Passes messages to and from the brain, and connects nerves to the PNS
What does adrenaline trigger?
Physiological changes in the body, during a time of fight or flight