PSY1EFP Lecture Notes - Lecture 4: Autonomic Nervous System, Peripheral Nervous System, Neuroplasticity
18 Jun 2018
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EFP Lecture 4 Session 1 – Brain Behaviour Relationships (3)
The Peripheral Nervous System
2 Primary Components
Somatic Nervous System: a component of the peripheral nervous system; it transmits sensory signals and motor
signals between the central nervous system and the skin, muscles, and joints.
Autonomic Nervous System (ANS): a component of the peripheral nervous system; it transmits sensory signals
and motor signals between the central nervous system and the body’s glands and internal organs.
Sympathetic & Parasympathetic Divisions
The autonomic nervous system has two divisions.
-Sympathetic division: A division of the autonomic nervous system; it prepares the body for action.
- Parasympathetic division: A division of the autonomic nervous system; it returns the body to its resting
state.
Most internal organs are controlled by inputs from the sympathetic and the parasympathetic systems.
The Endocrine System Communicates
through Hormones
Endocrine system: a communication system that uses hormones to
influence thoughts, behaviours, and
actions
-The main difference is that the nervous system uses electrochemical
signals to communicate and the endocrine system uses hormones to
communicate.
Hormones: Chemical substances, released from endocrine glands, that travel through the bloodstream to
targeted tissues; the tissues are subsequently influenced by the hormones.
Hormone Effects on Sexual Behaviour
Gonads: the main endocrine glands involved in sexual behaviour: in males, the testes, and in females, the ovaries
Gonadal hormones are identical in males and females.
-But androgens (testosterone) are more prevalent in males.
-And estrogens (oestradiol and progesterone) are more prevalent in females.
Actions of the Nervous & Endocrine System are coordinated
Pituitary gland: A gland located at the base of the hypothalamus; it sends hormonal signals to other endocrine
glands, controlling their release of hormones.
-Neural activation causes the hypothalamus to secrete a particular releasing factor, which causes the pituitary
gland to release a hormone specific to that factor.
- Growth hormone (GH) prompts bone, cartilage, and muscle tissue to grow or helps them regenerate after
injury.
How does the Brain change?
Despite the great precision and the specificity of its connections, the brain is extremely adaptable.
- Plasticity: a property of the brain that allows it to change as a result of experience or injury
Experience Fine-Tunes Neural Connections
- Chemical signals influence cell growth and cell function.
-Experiences, particularly during critical periods, influence cell development and neural connections.
Females & Males Brains are mostly similar but may have revealing differences
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Female and male brains have differences that are reflected in psychological functioning.
- Males, larger size (1400g versus 1200g)̴ ̴
-Females, better language
- There is evidence that men and women may perform the same task by using different parts of the brain.
- Evidence indicates that females’ brains are more bilaterally organized for language.
-In males’ brains the equivalent language areas are more likely to be in only one hemisphere, usually the left.
Males Brains vs Female Brains
A is a fMRI scan of a male brain while they listened to someone read aloud. Only one side of the brain is
highlighted. Image B is a fMRI scan of a female brain while they listened to
A considerable body of evidence indicates that female brains are more bilaterally organized for language than
males’ brains. For example, researchers studied men and women listening to someone reading aloud. As these
fMRI images show, (a) the men listened with one side of their brains, whereas (b) the women tended to listen
with both sides.re
The Brain Rewires itself throughout life
Although brain plasticity decreases with age, the brain can grow new connections among neurons and even grow
new neurons into very old age
The rewiring and growth within the brain represents the biological basis of learning
Changes In the strength of connections underlies learning
Changes in the brain due to experience are mainly in the strength of existing connections
-Hebb’s “fire together, wire together” catchphrase: When two neurons fire simultaneously, the synaptic
connection between them strengthens
Entirely new connections can grow between neurons.
Neurogenesis: New neurons are produced in some brain regions (e.g., the hippocampus)
Neurogenesis may underlie neural plasticity
Changes in the Brain
Wiring in the brain is affected by amount of use
Phantom limb: the intense sensation that an amputated body part still exists
Phenomenon suggests that the brain has reorganized in response to the injury and that the missing limb’s
cortical representation remains intact but altered
An amputee who has lost a hand may, when his or her eyes are closed, perceive a touch on the cheek as if it were
on the missing hand
Amputation of the 3rd digit causes amendment of the mape
Cortical remapping following amputation
Training associated brain changes
Training juggling skills: increased volume in cortex related to visual motion detection and visual-motor
coordination – increased cell size or synaptic expansion?
Summary
The interplay of genes and environment wires the brain
Culture affects the brain
The brain rewires itself throughout life
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Efp lecture 4 session 1 brain behaviour relationships (3) Somatic nervous system: a component of the peripheral nervous system; it transmits sensory signals and motor signals between the central nervous system and the skin, muscles, and joints. Autonomic nervous system (ans): a component of the peripheral nervous system; it transmits sensory signals and motor signals between the central nervous system and the body"s glands and internal organs. Sympathetic division: a division of the autonomic nervous system; it prepares the body for action. Parasympathetic division: a division of the autonomic nervous system; it returns the body to its resting state. Most internal organs are controlled by inputs from the sympathetic and the parasympathetic systems. Endocrine system: a communication system that uses hormones to influence actions thoughts, behaviours, and. The main difference is that the nervous system signals to communicate and the endocrine communicate. uses electrochemical system uses hormones to.
