TỔNG HỢP HƠN 100 ĐỀ THI THỬ TỐT NGHIỆP THPT TOÁN 2024 - TỪ CÁC TRƯỜNG, TRƯỜNG...
Chapter 28 Intro notes about Neurons 2016 to be used first.pptx
1. Starting small: The Neuron
• neuron: a nerve cell;
receives signals from other
neurons or sensory organs,
processes these signals, and
sends signals to other
neurons, muscles, or bodily
organs
– the basic unit of the nervous
system
2. The Neuron
• 3 types of neurons:
– 1. sensory neurons: respond to input from sensory
organs (skin, eyes, etc.)
– 2. motor neurons: send signals to muscles to control
movement
– 3. interneurons: connect the sensory neurons and
motor neurons
• most of the neurons in the brain = interneurons
• average human brain 100 billion neurons
4. Structure of the Neuron
• cell body (soma): the central part of the neuron, contains
the nucleus
– regulates cell functioning
• dendrites: the branching part of the neuron that receives
messages from other neurons and relays them to the cell
body
5. Structure of the Neuron
• axon: the long, cable-like extension that delivers messages to other
neurons
• myelin sheath: layer of fatty tissue that insulates the axon and helps
speed up message transmission
– multiple sclerosis: deterioration of myelin leads to slowed
communication with muscles and impaired sensation in limbs
• knobs: structure at the end of one of the axon’s branches that
releases chemicals into the space between neurons, when the neuron
is fired
6. From Neuron to Neuron
• ≈100 billion neurons in a human brain,
connected to an average of 10,000 others;
some up to 100,000
• synapse: the place where an axon of one
neuron meets with the dendrite/cell body of
another neuron
8. From Neuron to Neuron
• neurotransmitters:
a chemical that
sends signals from
one neuron to
another over the
synapse
9. From Neuron to Neuron
• Neurotransmitters are
stored in vesicles in
the knobs, and bind to
receptors on the cell
membrane of the next
neuron.
–Each receptor can
only bind with one
kind of
neurotransmitter.
10. (Some) Neurotransmitters
Neurotransmitter Function Examples of
malfunctions
Acetylcholine
(ACh)
Enables muscle action,
learning & memory
Alzheimer’s disease
less ACh production
Dopamine Influences movement,
learning, attention, &
emotion
Excess
schizophrenia
Undersupply
Parkinson’s disease
Serotonin Affects mood, hunger,
sleep, and arousal
Undersupply
depression
Norepinephrine Helps control alertness &
arousal
Undersupply
depressed mood
Glutamate Excitatory neurotransmitter
involved in memory
Excess
overstimulation of
brain, seizures
11. Central Nervous System (CNS)
Brain Spinal Cord
Peripheral Nervous System (PNS)
Sensory Neurons
Motor Neurons
Somatic Nervous System
• voluntary movements via
skeletal muscles
Autonomic Nervous System
• organs, smooth muscles
Sympathetic
- “Fight-or-Flight” responses
Parasympathetic
- maintenance
The Nervous System
The Nervous System
12. The Nervous System
• Made up of the
1. central nervous system
and the
2. peripheral nervous system
13. The Nervous System
The Central Nervous
- brain and spinal cord
• Peripheral Nervous System: links
central nervous system to organs
–comprised of the somatic nervous system
and the autonomic nervous system
(sympathetic and parasympatheic nerves)
