nervous system and endocrine system Flashcards
What makes up the nervous system?
The nervous system is made up of the brain and the spinal cord, while the peripheral nervous system (PNS) relays messages from the environment to the CNS, via sensory neurones, and from the CNS to effectors, via motor neurones.
What are the two subdivisions of the peripheral nervous system (PNS)?
The PNS is subdivided into the autonomic nervous system and the somatic nervous system.
What does the autonomic nervous system control?
The autonomic nervous system controls involuntary, vital functions of the body, such as maintaining heart rates and breathing rates.
What is the role of the somatic nervous system?
The somatic nervous system receives information from sensory receptors belonging to each of the 5 senses and stimulates effectors via motor neurones.
What are the two branches of the autonomic nervous system?
The autonomic nervous system is subdivided into the sympathetic and parasympathetic branches.
How do the sympathetic and parasympathetic branches work together?
These branches work as part of an antagonistic pair during the ‘rest and digest’ response and are crucial for the fight or flight response.
What physiological changes does the sympathetic nervous system induce?
The sympathetic nervous system increases heart rates, breathing rate, causes vasoconstriction, and pupil dilation.
What physiological changes does the parasympathetic nervous system induce?
The parasympathetic nervous system decreases heart rate, breathing rates, causes vasodilation, and pupil constriction.
What is the role of the endocrine system?
The endocrine system is the main chemical messenger system of the body, where hormones are secreted into the bloodstream from glands and transported to target cells.
What is considered the ‘master’ gland of the endocrine system?
The pituitary gland is considered to be the ‘master’ gland because it controls the release of hormones from all other glands in the body.
What hormone does the thyroid release and what is its effect?
The thyroid releases the hormone thyroxine, which increases heart rate and the rate of growth.
What hormone does the adrenal gland release and what is its role?
The adrenal gland releases adrenaline, which creates physiological arousal preceding the fight or flight response.
What is the first step in the fight or flight response?
The body senses and becomes aware of a stressor in the environment, e.g., the sound of a speeding car.
How does the body respond to a stressor?
Through sensory receptors and sensory neurones in the PNS, information is sent to the hypothalamus, which coordinates a response and triggers increased activity in the sympathetic branch of the ANS.
What happens after adrenaline is released during the fight or flight response?
Adrenaline is transported to target effectors via the blood, resulting in physiological changes such as rectum contraction and inhibited saliva production.
