The nervous system and the endocrine system regulate and control the activities of the other body systems
The nervous system may be divided into two parts:◦central nervous system (CNS): made up of
the brain and spinal cord◦peripheral nervous system (PNS): made up
of cranial and spinal nerves
The Brain◦ Cerebrum*◦ Cerebellum*◦ Brain Stem*◦ Medulla Oblongata*◦ Thalamus**◦ Hypothalamus**◦ Midbrain◦ & MORE!!
The Spinal Cord
Brain: major portion of the central nervous system◦ Cerebrum
What we think of as “The Brain” Largest organ of the
nervous system Consists of two
hemispheres: Right and Left
Brain (cont’d) Four Lobes
◦ Frontal-associated with reasoning, planning, emotions, problem solving, movement
◦ Parietal-associated with movement, orientation, recognition, perception of stimuli
◦ Occipital-associated withvisual processing
◦ Temporal-associatedwith processing andrecognition of sounds, memory, andspeech
◦ Activity-Stroop Effect
Brain (cont’d)◦ ventricles: spaces within the cerebrum that
contain a fluid called cerebrospinal fluid (CSF), which flows through the space around the brain and spinal cord
◦ cerebral spinal fluid (CSF): clear, colorless fluid to cushion the brain and spinal column from shock; transports nutrients, and clears metabolic waste
Brain (cont’d) Medulla
◦ Controls involuntary actions◦ Looks like a swollen lump ◦ Located at top of spinal cord◦ Inside, two large cords of nerve fibers
One from Left hemisphere One from Right hemisphere The cords cross here
Brain (cont’d) Each half of the brain interacts with one half
of the body The connections are crossed Right brain-Left hand; Left brain-Right hand Left side dominant for language—talking
and understanding language Activity
Brain (cont’d) Cerebellum
◦ Means “little brain”◦ Size of a pear◦ Located at the rear of cerebrum◦ Coordinate movements via
commands from the cerebrum◦ Activity: Balancing Act
Brain (cont’d) Brain Stem
◦ Located below the cerebrum◦ Connects the brain with the
spinal cord◦ Sends messages from the
brain to the spinal cord◦ Involved in cardiovascular
system control, respiratory control, pain sensitivity control, alertness, awareness, and consciousness
Spinal cord◦ Passes through the vertebrae extending from the medulla
oblongata to the level of the 2nd lumbar vertebra; conducts nerve impulses to and from the brain and initiates reflex action to sensory information without input from the brain
◦ Responsible for primitive involuntary reactions called reflexes
◦ Pairs of Spinal Nerves: Cervical (8) Thoracic (12) Lumbar (5) Sacral (5) Coccygeal (1)
The nerves outside the brain and spinal cord Nerve: cordlike structure that carries
impulses from one part of the body to another
Connects the Central Nervous System to the rest of the body◦ Consists of two parts
SomaticVoluntary
AutonomicAutomatic! Involuntary
Voluntary Involuntary
All the actions that we choose to do:
StudyingPracticing SportsSingingWhat else?
All the actions that our brain controls without us knowing:
DigestingBreathingRegulating Body
TemperatureWhat else?
Cells of the nervous system are called neurons
13-33 Billion Neurons in the brain alone Parts of a Neuron
◦ Nucleus-stores genetic information◦ Axon-string like structure that transmits impulses
to the next cell◦ Dendrites-tree like structure that receives impulses
from the previous cell◦ Cell Body-bulbous end that contains the nucleus◦ Terminal Fibers-the end of the axon◦ Myelin Sheath-insulation-like covering around axon
A neuron has many of the same organelles such as mitochondria, cytoplasm and a nucleus, as other cells in the body.
Neurotransmitters are chemicals or molecules that help send synapses
Neurons send and receive impulses electrochemically
This is called a synapse: syn=together, haptein=to clasp
Each cubic mm of brain contains roughly a billion synapses
Synaptic cleft—space between neurons Axon terminal-part of neuron that sends
impulse to the next neuron Dendrite-part of neuron that receives
impulse from the previous neuron
Head injury Problems with development Damaged or dead nerve cells Loss of blood flow to the brain Cancer Infection
Avoid tobacco, drug, and alcohol use Drink plenty of water Get sleep! Eat healthy foods Never compromise your breathing Wear helmets when pertinent
6A:6-8◦ Like other animals, human beings have body
systems for…coordination of body functions◦ Although social behaviors are affected by both
genes and environmental factors, human beings are still able to invent, learn, and modify a wide variety of these behaviors
◦ Interactions among the senses, nerves, and brain make possible the learning that enables human beings to predict, analyze, and respond to changes in their environment