Nervous System Flashcards
(16 cards)
What are the different parts of the nervous system (all)?
- Central NS & Peripheral NS
- Brain & Spinal cord
- Somatic NS & Autonomic NS
- Sympathetic NS & Parasympathetic NS
Outline the Brain
- the centre of all conscious awareness
- the outer layer (cerebral cortex) is highly developed
Outline the spinal cord
- an extension of the brain
- responsible for reflex actions
- passes messages to and from the brain & connects nerves to peripheral nervous system
Outline the nervous system
- specialised network of cells (neuron’s)
- our primary internal communication system
- passes electrical and chemical signals
- two main functions: to collect, process and respond to information in the environment & to coordinate the working of different organs and cells in the body
Outline the somatic nervous system
- consists of sensory and motor neurons
- transmits sensory information from the body to the brain
- transmits information from the brain to the muscles to produce movements
Outline the autonomic nervous system
- transmits information to & from internal organs
- governs vital (automatic) functions, e.g. breathing
Outline the sympathetic nervous system
- works alongside the endocrine system to bring about physiological arousal
- fight or flight response
Outline the parasympathetic nervous system
- works alongside the endocrine system, to return the body to its resting state in the ‘rest and digest’ response
Outline a sensory neuron
- Carries nerve impulses from the PNS to the brain & spinal cord (CNS)
- Found in the eyes, ears, skin and tongue
- LONG dendrites, SHORT axons
- Myelinated
- Cell body to the side
- When the impulses reach the brain they are transported into sensations (e.g. visual input creates sensation of heat or pain) so the organism can react appropriately
Outline a relay neuron
- Mostly within the brain & spinal cord (CNS)
- SHORT dendrites, SHORT axons
- Both dendrites & axon are short, so it is not myelinated
- Allows sensory & motor neurons to communicate
Outline a motor neuron
- Conducts signals from the CNS to muscles/glands
- Cell bodies are in the central nervous system (CNS)
- SHORT dendrites, LONG axons, so myelinated
- Form part of the peripheral nervous system (PNS)
- Form synapses with muscles and control their contractions
What travels from the vesicles in the pre-synaptic nerve, across the synapse, and into the receptors of the dendrites?
Neurotransmitters
What is the function of the endocrine system?
1- Communicates chemical messages to the organs of the body by releasing hormones from glands into the bloodstream
2 - which then bind with specific receptors to regulate the activity of the cells or organs in the body
What hormones does the pituitary gland release, and what are their functions?
Hormones: LH, FSH, ACTH (and more)
Functions:
- Regulates the function of other glands
- LH & FSH stimulate oestrogen and progesterone from the ovaries
- ACTH stimulated adrenaline and cortisol from the adrenal glands
What hormones does the adrenal gland release, and what are their functions?
Hormones: Cortisol, Aldosterone, Adrenaline, Noradrenaline
Functions:
- Cortisol regulates a variety of bodily functions, including cardiovascular & anti-inflammatory functions
- Aldosterone maintains blood volume and blood pressure
- Adrenaline & Noradrenaline prepares the body for ‘fight or flight’; adrenaline increases heart rate & inhibits digestion, noradrenaline constructs blood vessels, so blood pressure increases.
Explain ‘Fight or Flight’
- A stressor is perceived by the hypothalamus
- This stimulates the sympathetic nervous system (SNS)
- The SNS causes the adrenal medulla to release the hormone adrenaline (and noradrenaline) into the bloodstream
- This generates the fight or flight response
