01. CNS, Neurons and Synapses Flashcards
Describe the nervous system.
-A complex network of specialised cells.
-Role is to receive, process and respond to information in the environment and to coordinate different organs and cells in the body.
-The nervous system has 2 main parts, the CNS and the peripheral nervous system (PNS).
-The CNS consists of the brain and spinal cord.
Define the brain.
The brain is the main data centre of the body and consists of the cerebrum which regulates higher level functioning such as thought, and the cerebellum which maintains coordination.
Define the brain stem.
The brain stem includes the midbrain, pons and medulla, and controls lower level functioning such as respiration and digestion. It connects the brain and the spinal cord.
Define the spinal cord.
-The spinal cord connects the brain and the body’s main receptors, and serves as a conduit for sensory input and motor output.
-Responsible for reflex actions.
Define the cerebrum.
In humans, it is the largest part of the brain and is the seat of motor and sensory functions, and the higher mental functions such as consciousness, thought, reason, emotion and memory.
Define the thalamus.
-The brain’s relay station.
-Receives information from various senses and passes it onto appropriate areas of the cerebral cortex for higher level processing.
-Acts as filter of information.
-Plays a role in sleep and OCD.
Define the hypothalamus.
-Controls motivational behaviours such as hunger, thirst and sex.
-Stress response ‘fight or flight’.
-Maintains balance in many bodily functions such as temperature (homeostasis).
-Regulates the endocrine system via pituitary gland.
Define the limbic system.
-Emotion centre of the brain.
-Has a role in memory and learning.
Define the cerebellum.
-Part of the hindbrain in vertebrates.
-Receives and integrates information from the spinal cord.
-In humans it lies between the brainstem and the cerebrum, and plays an important role in sensory perception, motor output, balance and posture.
-Coordinates posture, balance and movement.
What connects the two hemispheres of the brain?
-A dense collection of nerve cells called the corpus callosum.
-Allows communication between the hemispheres by passing signals back and forth.
Define lateralisation.
Two hemispheres have different functions.
Define localisation.
Certain areas are responsible for different functions.
Define the cerebral cortex.
-The cerebral cortex of both hemispheres is subdivided into 4 lobes (so there are 8 lobes in total, 4 in each hemisphere).
-The cerebral cortex is very wrinkly so it has a higher surface area, giving it more processing power.
Define the frontal lobes.
(One of the cerebral cortex 4 lobes)
-Located at the front of the brain.
-Make up about 40% of the cerebral cortex.
-Control thinking, planning, problem solving and decision making.
Define the parietal lobes.
(One of the cerebral cortex 4 lobes)
-Key part of your understanding of the world around you.
-It processes your sense of touch and assembles input from your other senses into a form you can use.
-Helps you understand where you are in relation to other things that your senses are picking up around you.
Define the temporal lobes.
(One of the cerebral cortex 4 lobes)
-Each lobe contains an auditory cortex which deals with sound information coming mainly from the opposite area.
-Play role in understanding language.
Define the occipital lobes.
(One of the cerebral cortex 4 lobes)
-Located in back of brain.
-Visual processing area of brain.
Define the Broca’s area.
(Language areas of the brain)
Responsible for speech production.
Define the Wernicke’s area.
(Language areas of the brain)
Comprehension of speech.
Define a neuron.
-Neurons are nerve cells.
-There are roughly 100 billion neurons in the human nervous system and 80% of these are located in the brain.
-Neurons receive, process and transmit messages through chemical and electrical signals within the body,
What are the 3 types of neuron?
- Relay neuron
- Sensory neuron
- Motor neuron
Define a relay neuron.
-Relay neurons connect sensory and motor neurons together, and also connect to other relay neurons.
-They have short dendrites and short axons and are only found in the CNS.
Define a sensory neuron.
-Sensory neurons carry messages from sensory receptors (eg touch and temperature sensitive receptors in the skin) along nerves in the peripheral nervous system (PNS) to the central nervous system (CNS).
-They have long dendrites and short axons.
Define a motor neuron.
-Motor neurons carry messages from the CNS, along nerves in the PNS, to effectors in the body (eg muscles and glands).
-They have short dendrites and long axons.