Download Chapter 6 Notes - Biological Psych

Chapter 3
Biology and Behavior
• Sensation, perception, memory,
and thinking are all psychological
processes that have at least a
partly biological basis.
• Three major areas of study for
biological psychologists include
the nervous system, the
endocrine system, and heredity.
Nervous System
• The human nervous system is
working when we are active or
still, awake or asleep.
• Two main parts:
• Central nervous system consists
of brain and spinal cord.
• Peripheral nervous system is
made up of nerve cells that send
messages between the central
nervous system and all the parts
of the body.
• The cerebrum – the front of the brain
The largest part of the brain located in the front
is called the cerebrum. The cerebrum is
responsible for:
• Movement
• Body temperature
• Touch
• Vision
• Hearing
• Judgment
• Reasoning
• Problem solving
• Emotions
• Learning
• The cerebrum has 2 parts: the right
cerebral hemisphere and the left cerebral
hemisphere. They are connected at the
bottom and have a deep groove running
between them. In general, the right
cerebral hemisphere controls the left side
of the body, and the left cerebral
hemisphere controls the right. The right
side is involved with creativity and artistic
abilities. The left side is important for logic
and rational thinking.
• The hemispheres of the cerebrum are
divided into lobes, or broad regions of the
brain. Each lobe is responsible for a
variety of bodily functions:
• Frontal lobes are involved with personality,
speech, and motor development
• Temporal lobes are responsible for
memory, language and speech functions
• Parietal lobes are involved with sensation
• Occipital lobes are the primary vision
centers
• The surface of the cerebrum appears wrinkled
and is made up of deep grooves and bumps or
folds. The outer part of the cerebrum is called
gray matter and contains nerve cells. The inner
part is called white matter and contains
connections of nerves.
• The brainstem is located in front of the
cerebellum. The brainstem is like the hard-drive
of a computer. It is the main control panel for the
body that passes messages back and forth
between the brain and other parts of the body.
The cerebrum, the cerebellum, and the spinal
cord are all connected to the brainstem. The
brainstem has three main parts, the midbrain,
the pons, and the medulla oblongata.
• The brainstem controls vital functions of
the body, including:
• Breathing
• Consciousness
• Cardiac function
• Involuntary muscle movements
• Swallowing
• Movement of the eyes and mouth
• Relaying sensory messages (pain, heat,
noise, etc.)
• Hunger
• The cerebellum – the back of the brain Behind
the cerebrum at the back of the head is the
cerebellum. In Latin, cerebellum means “little
brain.” However, the cerebellum contains more
nerve cells than both hemispheres combined.
The cerebellum is primarily a movement control
center, responsible for:
• Voluntary muscle movements
• Fine motor skills
• Maintaining balance, posture, and equilibrium
• Unlike the cerebrum, the left cerebellum controls
the left side of the body, and the right cerebellum
controls the right side of the body.
• Nerve cells called neurons run
through our entire bodies and
communicate with each other.
• They send and receive messages
from other structures in the body
such as muscles and glands.
• Neurons resemble tree structures
(branches, trunk, and roots).
• Unlike trees, neurons can also lie
end to end. “Roots” can
intertwine with “branches” of
neurons that lie below.
• Each neuron has a cell body,
dendrites, and an axon.
• A neuron has many dendrites but
only one axon, which vary greatly
in length.
• Many axons are covered in
myelin which insulates and
protects the axon and also helps
to speed up the transmission of
the message.
• At the end of the axon, small
fibers, axon terminals branch out.
• Messages are sent from the axon
terminals of one neuron to the
dendrites of other neurons.
• It must cross the synapse.
Messages travel in only one
direction.
• New synapses can develop
between neurons that were not
previously connected.
• Information sent and place that it
goes depends on a number of
factors – locations and events.
• Sensory neurons are nerve cells
that carry information received by
the senses to the central nervous
system.
• Motor neurons are nerve cells
that carry information from the
central nervous system to the
muscles and the glands and
influence their functioning.
• Neurons send messages across
synapses through the release of
neurotransmitters.
• A neuron fires its neurotransmitters
like water droplets shooting out of a
spray bottle.
• There are several types of
neurotransmitters, each with its own
specific structure and fits into a
receptor site on the next neuron.
• The message is converted into an
electrical impulse that travels the
length of the neuron, then it is
transmitted to the next neuron by
neurotransmitters.
• The process continues until the
next message arrives at its
destination, and takes only a
fraction of a second.
• There are dozens of types of
neurotransmitters with different
functions:
• acetylcholine – control of skeletal
muscles
• dopamine – motor behavior
• noradrenaline – prepares the
body for action
• serotonin – emotional arousal and
sleep
• All messages are carried via the
spinal cord and the peripheral
nervous system.
• The central nervous system
consists of the neurons of the
spinal cord and the brain.
• The spinal cord is a column of
nerves about as thick as the
thumb and is protected by bones.
• The spinal cord transmits
messages between the brain and
the muscles & glands throughout
the body.
• The peripheral nervous system
lies outside the central nervous
system and is responsible for
transmitting messages between
the central nervous system and
all parts of the body.
• There are two main divisions:
• Somatic nervous system –
transmits sensory messages to
the central nervous system.
• Autonomic nervous system –
regulates the body’s vital
functions such as heartbeat,
breathing, digestion, and blood
pressure.
• The autonomic nervous system has
two divisions with opposing
functions:
• sympathetic nervous system –
activated when a person is going
into action, fight or flight response.
• parasympathetic nervous system –
restores the body’s reserves of
energy after an action has occurred.