Chapter 2 Flashcards
What are neurons?
A specialized cell that carry electrochemical messages through the nervous systems.
What are the parts of the Neuron?
Cell body/ Soma, Dendrites, Axons covered with myelin sheath. Nodes of Ranvier.
What is the process?
Dendrites receive signals, process the signal in the cell body, convert this signal into an action potential that is transmitted along an axon. The myelin coat increase speed of electrical message.
What are the types of glial cells?
These surrounds and protect the neurons. Astrocytes clean up the environment and oligodendrites produce myelin.
What are the types of neurons and where do they play a role?
Afferent neurons (sensory): relay info from 5 senses to CNS Efferent neurons (motor): relay info from CNS Interneurons: carry info within CNS
What are the periods of firing a neuron?
(1) Resting potential is negative!
(2) Then when the neuron is stimulated, action potential, neuron is depolarized
(3) Refractory period
(4) Resting potential
This is an all or nothing process
Structures involved in a synapse.
Axon terminal, synaptic vesicles, neurotransmitters and synaptic cleft. There are 1 trillion synapses in the human body.
Difference between electrical and chemical messages?
Electrical messages are within a neuron while chemical substances send messages between neurons at the level of the synapse.
Examples of Neurotransmitters.
Acetylcholine
Amino acids
Glutamate
GABA
Endorphins
Monoamines
Dopamine
Epinephrine
Norepinephrine
SerotoninWhat does the CNS and PNS composed of?
CNS: Brain and spinal cord
PNS: Nerves around the body
What is a reflex?
It involves the spinal cord and PNS which can initiate movement on its own. Reflex does not require the brain.
What is the brainstem? What does it do?
Where the spinal cord connects to the brain.
- Reticular formation: helps shut down the brain, wakes us up, screens incoming stimuli. Involved in arousal, alertness and attention.
- Medulla: Regulates automatic body functions such as respiration, heartbeat, BP, swallowing, coughing, blinking and smiling.
- Pons: Relays info from motor cortex to cerebellum, involved in respiration, movement, sleep/wake/dreaming and relaxation
Function of the cerebellum.
Coordination, skilled movement, balance, also cognition, attention and emotion.
Functions of the Thalamus’s
- The thalamus is the relay station of all the senses except for smell which gets processed by the amygdala. Also involved in learning languages and sleep.
- The hypo (below) thalamus is important to regulate our temperature, regulates hunger, thirst, sexual behaviour, emotion, biological clock and controls the pituitary gland.
What is the Limbic system?
Structures of the brain involved in emotion and memory. The amygdala is for the production and regulation of emotions, fear and aversive. The hippocampus is involved in forming and retrieving memories and sense of direction.
What is the limbic system composed of?
- Frontal lobe (conscious)
- Thalamus (transfer)
- Hippocampus (memory)
- Amygdala (gen. emotion)
- Hypothalamus (directs stress response)
- Olfactory bulb (smell that goes to the amygdala)
Breakdown of the Human nervous system.
NS CNS Brain and Spinal Cord
PNS
Somatic nervous system: Can control
Autonomic nervous system (can’t control)
Sympathetic: Arouses body, response for F & F
Parasympathetic: Restore homeostasis
What connects the two cerebral hemispheres?
Corpus callosum
What is the cerebral cortex?
A thin outer coating responsible for language, memory, and thinking.
What is grey and white matter?
Grey matter is where dendrites and cell bodies (somas) are located.
White matter is where axons with myelin is found.
What are the three type of areas of the cerebral cortex?
- Sensory input areas where vision, hearing, touch and pressure are registered.
- Motor areas which control voluntary movement.
- Association areas which house our memories and are involved in thought, perception and language.
What are the 4 lobes of the brain?
Frontal, Parietal, Occipital, Temporal
What is Broca’s area?
In the frontal left hemisphere responsible for production of speech. Without, you also can’t write.
What is the frontal lobe responsible for?
Thinking, personality, emotions, memory, impulse control and planning. Speech production. Also, muscle related to speech from the motor cortex.
What did Wilder Penfield do?
He mapped the motor cortex which was not equally represented by our body parts – Homunculi
What is the parietal lobe responsible for?
For interpreting bodily sensation and for special sense. Houses the somatosensory cortex. Also houses our memory of how objects feel.
What is the occipital lobe responsible for?
This is where vision is processed in the visual cortex. The association areas are involved in the interpretation of visual information, holds memory of past visual experiences.
What is the temporal lobe responsible for?
Processes auditory information with the primary auditory cortex that perceives and recognizes sound. Also, for language comprehension. Temporal association areas interpret auditory stimuli.
What is Wernicke’s Aphasia?
Fluent speech, articulated words but comes out as gibberish.
What is laterization?
Whereby the left hemisphere controls and senses the right side and the right hemisphere controls and senses the left side.
Processing of emotions.
Negative emotions are processed on the right side; positive emotions are processed on the left side.
