5 The Nervous System Flashcards
What are the main components of the Central Nervous System?
brain and spinal cord
What are the general functions of the nervous system?
- sensory
- detection and input
- integrative
- procsessing/storing/analyzing of sensory info
- decision-making
- motor
- output
What are the 2 types of nervous tissue cells?
neuroglia and neurons
What are the general functions of neuroglia?
- support
- nourish
- protect
What are the 3 parts of nerve cells?
dendrite, cell body, axon
Describe a multipolar neuron and where they tend to be found in the body.
- several dendrites and one axon
- most neurons in the brain and spinal cord and all motor neurons
Describe a bipolar neuron.
one main dendrite and one axon
Describe unipolar neurons.
- peripheral axon has sensory receptors
- central axon has axon terminals
- all sensory neurons in the PNS are unipolar
How are neurons functionally classified?
- sensory neurons
- motor neurons
- interneurons
What are the two types of synapses?
electrical and chemical
Define neurotransmitter.
a chemical released by the pre-synaptic neuron to affect (excite or inhibit) the post-synaptic neuron(s) or effector (muscle/gland)
NB: neurotransmitter (NT) receptors are specific to the NT released (think lock and key)
How do electrical synapses work?
APs conduct directly between the plasma membranes of adjacent cells through gap junctions (faster than chemical; allows for syncyhronization of function)
How do chemical synapses work?
- when the AP reaches the end of the pre-synaptic neruon, it causes the release of a neurotransmitter that diffuses across the synaptic cleft, binds to the post-synaptic neuron
- if the nuerotransmitter is excitatory, continuation of the AP is more likely
if the nuerotransmitter is inhibitory, continuation of the AP is less likely - chemical synapses are slower (than electrical)
Are acetylcholine (ACh), dopamine, and seratonin neurotransmitters?
yes
What are the four types of neuroglia of the CNS?
- astrocytes
- oligodendrocytes
- microglia
- ependymal cells
What are the structures of the PNS?
- cranial nerves and their branches
- spinal nerves and their branches
- ganglia
- enteric plexuses
- sensory receptors
Referencing the nervous system, what’s a:
- nucleus
- ganglion
- tract
- nerve
- nucleus: a cluster of neuronal cell bodies in the CNS
- ganglion: a cluster of neuronal cell bodies in the PNS
- tract: a bundle of axons in the CNS
- tracts interconnect neurons in the spinal cord and brain
- nerve: a bundle of axons in the PNS
- spinal nerves connect the spinal cord to the periphery
- cranial nerves connect thye brain to the periphery
What are the four structural parts of the bain?
- brain stem
- cerebellum
- diencephalon
- cerebrum
What are the 3 regions of the brain stem?
- medulla oblongata
- pons
- midbrain
This contains centres (necluei) for the control of heart rate, blood pressure, breathing, swallwing, and vomiting:
medulla oblongata
Along with the medulla, this contains centres for the control of breathing:
pons
This contains:
- centres for reflex visual activities (e.g. reading, tracking moving objects, scanning stationary objects), hearing
- nuclei called the substantia nigra – neurons that make dopamine extend from it
midbrain
This is a net-like formation of neural tissue that spreads throughout the brain stem:
reticular formation
The reticular formation contains the reticular activating system (RAS) which helps:
- consciousness
- maintain attention
- prevent sensory overload by filtering out insignificant information
- regulates muscle tone
The hypothalamus, thalamus and epithalamus are located in which part of the brain?
diencephalon
What are the major functions of the hypothalamus?
- major regulator of homeostasis
- controls and integrates the autonomic nervous system
- hormone production
- emotion and behavious (with the limbic system)
- eating, drinking
- body temperature
- circadian rhythm (a 24 hour cycle in the biochemical, physiological and/or behavioural processes of living things)
What’s the major function of the thalamus?
the major relay station for most sensory input to the cerebral cortex
This is involved in smelling (especially emotional responses to smells). It also contains the pineal gland.
the epithalamus
What functions does the white matter of the brain deal with?
contains areas that deal with complex functions like memory, emotions, reasoning, will, judgment, personality traits, intelligence
What sorts of things is the basal ganglia (aka basal nuclei) responsible for?
- helps to regulate the starting and stopping of movements
- helps control subconscious contraction of skeletal muscles
- helps suppress unwanted movement
- helps to set resting muscle tone
- functionally, the basal ganglia are linked to the substantia nigra
What are functions the limbic system is involved in and what parts of the brain does it include?
- involved in emotion, smelling and memory
- it includes parts of the hypothalamus, the hippocampus, amygdala, and other nearby structures
What are the main functions of the hippocampus?
- functions in memory (necoding, consolidation and retrieval)
- very important in converting short term memory into long term memory)
Anterior median ___ and posterior median ___
- anterior fissure
- posterior sulcus
