The Brain and Nervous System Flashcards
Neurons
The basic building blocks of the nervous system
Generate electricity which creates nerve impulses
Releases chemicals that facilitate communication
DENDRITES
are branch-like extensions that receive inputs from other cells
SOMA
CELL BODY
genetic info in the nucleus, nucleus determines how the neuron will manipulate input from dendrites
AXON
controls the exchange of chemical substances in and out of the cell and transmits info from the nucleus to other neurons.
MYELIN SHEATH
insulates the axon from stimuli that may interfere with transmitting nerve impulses
GLIAL CELLS
support cells, hold neurons in place, absorb toxins, make nutrients
Steps in firing neurons
Neuron has an electric RESTING POTENTIAL with a negative charge inside the membrane and a positive charge outside
ACTION POTENTIAL occurs when the neuron is stimulated
Original ionic balance restored after firing, neuron rests
DEPOLARISATION
Shift in electrical charge distribution within a cell
ABSOLUTE REFRACTORY PERIOD
The neuron cannot fire until regains its natural resting charge
GRADED POTENTIALS
Change to the resting potential that does not reach the threshold. A combination of graded potentials may trigger an action potential
HOW NEURONS COMMUNICATE
Communicate through the SYNAPTIC SPACE (space between)
NEUROTRANSMITTERS and its types
Chemical substances that carry messages across synaptic space
EXCITATORY neurotransmitters excite the neuron and cause an action potential to fire
INHIBITORY neurotransmitters inhibit the neuron and prevent firing
TYPES OF NEURONS
SENSORY NEURONS: carry messages from sensory organs to the brain (out to in)
MOTOR NEURONS: transmits impulses from the brain to organs/ muscles (in to out)
INTERNEURONS: perform connective and associative functions (linking neurons together)
PERIPHERAL NERVOUS SYSTEM (PNS)
Made of two subdivisions: the somatic and the autonomic nervous systems
THE SOMATIC NERVOUS SYSTEM
Allows us to sense and respond to the environment
AUTONOMIC NERVOUS SYSTEM
Consists of a SYMPATHETIC NERVOUS SYSTEM & PARASYMPATHETIC NERVOUS SYSTEM
SYMPATHETIC NERVOUS SYSTEM
activates the body in response to threats; activates the organism.
PARASYMPATHETIC NERVOUS SYSTEM
calms down the body and maintains energy
CENTRAL NERVOUS SYSTEM (CNS)
Connect PNS with the brain
Hindbrain
Brain stem
cerebellum
BRAIN STEM supports vital life functions
- MEDULLA: heart rate, respiration, vasomotor, blood pressure, vomiting. Link spine and brain
- PONS: carries nerve impulses between the higher and lower nervous system, regulates sleep
CEREBELLUM: coordination, learning, memory
RETICULAR FORMATION: consciousness and arousal
Midbrain
tectum
tegmentum
TECTUM: vision and hearing
TEGMENTUM: movement and arousal
Forebrain
cerebrum
cerebral cortex
limbic system
CEREBRUM major structure of the forebrain
THALAMUS organises inputs
HYPOTHALAMUS motivation, emotion, sexual behaviour, temperature regulation, eating, drinking, and aggression.
LIMBIC SYSTEM coordinates behaviours to satisfy motivation, emotion, and reward/punishment.
- HIPPOCAMPUS: form and retrieve memories.
- AMYGDALA: emotional response patterns
BASAL GANGLIA: structures involved in movement and ‘autonomic’ responses/judgements
CEREBRAL CORTEX: unmyelinated cells that form the outer layer. Constructs complex voluntary movements for activities. Allows symbolic thinking
MOTOR CORTEX controls muscles for voluntary movement
SENSORY CORTEX input from sensory receptors
Lobes
OCCIPITAL LOBE: vision
PARIETAL LOBE: the sense of touch, perception of movement and objects in space
TEMPORAL LOBE: hearing language, objects in sight
FRONTAL LOBE
HEMISPHERIC LATERALISATION
Greater localisation of function in one hemisphere
LEFT
Verbal, speech, math, logic
More active when feeling positive emotions
RIGHT
Spatial relations, faces, mental imagery, musical and artistic abilities
More active when feeling negative emotions
