incredible nervous system

Incredible Nervous System

http://thebrain.mcgill.ca/flash/index_i.html

STUDYING THE LIVING BRAIN

• Brain scans– techniques that can look through the thick

skull and picture the brain with astonishingly clarity yet cause no damage to the extremely delicate brain cells


• EEG:– Electroencephalogram: studies the different electrical brain

waves generated by neurons. Gives a computerized read-out showing the activity on the brain’s surface.

CT/CAT Scans

http://www.youtube.com/watch?NR=1&v=rN4E8Y5loAs


1. MRI

– magnetic resonance imagery– involves passing nonharmful radio

frequencies through the brain2. fMRI

– functional magnetic resonance imaging– measures the activity of specific neurons

that are functioning during cognitive tasks, such as thinking, listening

fMRI

MRI

http://www.youtube.com/watch?v=9E1GoWhSlho&feature=related

http://www.youtube.com/watch?v=BmQR57V5TVU&feature=related

http://www.youtube.com/watch?v=uVht8AMknfc&feature=relatedhttp://www.youtube.com/watch?v=AUT9UTVrwp8&feature=related

http://www.youtube.com/watch?v=Cwda7YWK0WQ

STUDYING THE LIVING BRAIN3.PET scans

– positron emission tomography– involves injecting a slightly radioactive solution into the

blood and then measuring the amount of radiation absorbed by neurons

– http://www.youtube.com/watch?NR=1&v=d9iOxMFmPlA

transcranial magnetic stimulation

http://www.sciencedaily.com/releases/2005/10/051019003056.htm

ORGANIZATION OF THE BRAIN

…we will look at

• Major divisions of the nervous system

– central nervous system - CNS

– peripheral nervous system - PNS

PERIPHERAL & CENTRAL NERVOUS SYSTEM

…remember

• Peripheral Nervous System

– made up of nerves that are located throughout the body, except in the brain & spinal cord

• Central Nervous System

– made up of neurons located in the brain & spinal cord

Diagram of Nervous Systems

Central nervous system and peripheral nervous system

Peripheral Nervous System


• Peripheral nervous system - PNS– includes all the nerves that extend from

the spinal cord and carry messages to and from various muscles, glands, and sense organs located throughout the body

• Subdivisions of the PNS1. somatic nervous system2. autonomic nervous system - ANS

1. sympathetic division2. parasympathetic division


• Somatic nervous system– network of nerves that connect either to sensory

receptors or to muscles that you can move voluntarily, such as muscles in your limbs, back, neck, and chest

– nerves contain two kinds of fibers• Afferent

– sensory fibers; carry information to the brain• Efferent

– motor fibers; carry information from brain or spinal cord to the muscles

Introduction to Psychology, 7th Edition, Rod PlotnikModule 4: Incredible Nervous System


• Autonomic nervous system - ANS– regulates heart rate, breathing, blood pressure,

digestion, hormone secretion, and other functionsA. Sympathetic division– triggered by threatening or challenging physical or psychological

stimuli, increases physiological arousal and prepares the body for action (fight/flight)

B.Parasympathetic division– returns the body to a calmer, decreases physiological

arousal(decreases heart rate/lowers BP) and is involved in digestion

Homeostasis:• sympathetic and parasympathetic systems work together to

keep the body’s level of arousal in balance for optimum functioning

SYMPATHETIC/ PARASYMPATHETIC


• Major Parts of the Brain

1.Forebrain

2.Midbrain

3.Hindbrain


• Forebrain– largest part of the brain– has right and left sides

called hemispheres– hemispheres are

responsible for a number of functions, including learning and memory, speaking and language, emotional responses, experiencing sensations, initiating voluntary movements, planning, and making decisions

The Cerebral Cortex

Each hemisphere of the cerebral cortex is divided into four lobes

•Four lobes

–Frontal lobe

–Parietal lobe

–Occipital lobe

–Temporal lobe

CONTROL CENTERS: FOUR LOBES

• Wrinkled cortex– a thin layer of cells that

essentially covers the entire surface of the forebrain

– the evolutionary purpose of the outer cortex being wrinkled is that it is able to contain billions of more neurons than if it was a smooth surface

Frontal Lobe

• THE CEREBRUM:Frontal Lobe

• Behavior • Abstract thought processes • Speech• Attention • Intellect • Reflection • Initiative • Coordination of movements • Muscle movements • Skilled movements

overview: involved with personality, emotions, and motor behaviors

Frontal Lobe

• Frontal lobe: functions– motor cortex– narrow strip of cortex that

is located on the back edge of the frontal lobe and extends down its side

– involved in the initiation of all voluntary movements

– right side controls left– left side controls right– organization and function

of motor cortex

Language in the Brain

http://www.news-medical.net/health/The-Human-Brain.aspx

Parietal Lobe

• Sense of touch (tactile sensation)

• Appreciation of form through touch

• Response to internal stimuli

• Sensory combination and comprehension

• Some language and reading functions

• Spatial associations

Overview: involved with perception and sensory experiences

–location of somatosensory cortex:narrow strip of cortex that is located on the front edge of the parietal lobe and extends down its side

Parietal Lobe• Parietal lobe: function

– involved in several cognitive functions, including recognizing objects, remembering items, and perceiving and analyzing objects in space

Temporal Lobe

• Temporal Lobe

• Auditory memories

• Some hearing

• Music

• Fear

• Language

• Speech • Emotions

Overview:involved with hearing and speaking

Temporal Lobe• Temporal lobe: functions

– primary auditory cortexlocated on top edge of each temporal lobe, receives electrical signals from receptors in the ears and transforms these signals into meaningful sound sensations, such as vowels and consonants

– auditory association area:located directly below the primary auditory cortex

transforms basic sensory information, such as noises or sounds, into recognizable auditory information, such as words or music

Temporal Lobe• Temporal lobe: functions

– Broca’s area - frontal lobe

• located in left frontal lobe

• necessary for combining sounds into words and arranging words into meaningful sentences

– Wernicke’s area• located in the left temporal lobe

• necessary for speaking in coherent

sentences and for understanding

speech

Occipital Lobe

• Vision

• Reading

• Visual memory and associations

Overview: involved with visual processing

• Occipital lobe: functions

– Vision: primary visual cortex which is:

located at the very back of the occipital lobe

– receives electrical signals from receptors in the eyes and transforms these signals into meaningless basic visual sensations, such as lights, lines, shadows, colors, and

textures

Occipital Lobe

–visual association area:

transforms basic sensations, such as lights, lines, colors, and textures, into complete, meaningful visual perceptions, such as persons, objects, or animals

Lobe Review Slide

http://www.umich.edu/~cogneuro/jpg/Brod_sagtl.gif

Functional Areas of the Brain

Function Brodmann Area

Vision

primarysecondary

1718, 19, 20, 21, 37

Audition

primarysecondary

4122, 42

Body Sensation

primarysecondary

1, 2, 35, 7

Sensation, tertiary 7, 22, 37, 39, 40

Motor

primarysecondaryeye mov'tspeech

46844

Motor, tertiary 9, 10, 11, 45, 46, 47

Forebrain: Limbic System: The Old Brain

• Structures:– Hypothalamus– Amygdala– Thalamus– Hippocampus

The Limbic System though very basic and old constitutes a part of the Forebrain.

Forebrain: Limbic System: Old Brain

1. Hypothalamus– regulates many motivational

behaviors, including eating, drinking, and sexual responses; emotional behaviors such as arousing the body when fighting or fleeing, and secretion of hormones, such as occurs at puberty

2. Amygdala– located in the tip of the

hippocampus– receives input from all the

senses– evaluates the emotional

significance of stimuli and facial expressions, especially those involving fear, distress, or threat

LIMBIC SYSTEM: OLD BRAIN

3. Thalamus– gathers and processes

information from the senses– involved in receiving sensory

information, doing some initial processing, and then relaying the sensory information to areas of the cortex

4. Hippocampus– curved structure inside the

temporal lobe– Involved in saving many

kinds of fleeting memories by putting them into permanent storage in various parts of the brain

Midbrain

• Midbrain/Mesencephalon

– has areas for vision, hearing, eye and body movement

1. contains the reticular formation, which arouses the forebrain so that it is ready to process information from the senses

– essential for processing voluntary motor movement

2. VTA: mechanism greatly involved in the feeling of pleasure

3. Nucleus Accumbens: same as VTA (these neurons are linked with the VTA)

Hindbrain/Rhombencephalon

Hindbrain•Pons

–functions as a bridge to interconnect messages between the spinal cord and brain

•Medulla

–located on top of the spinal cord

–includes a group of cells that control vital reflexes, such as respiration, heart rate, and blood pressure

•Cerebellum

–located in the very back and underneath the brain

–involved in coordinating motor movements but not in initiating voluntary movements

Exploded View of the Cerebellum

1. Split-Brain Studies : What happens when the Corpus Callosum is severed?

2.Hemispheric Specialization What different abilities have each of the hemispheres developed?

Lastly! (The Last (2) Concepts we will cover

Corpus Callosum/Anterior Commisure

• (2) Brain structures that house millions of neural connections between the (2) hemispheres

• Communication between the left and right hemispheres of the brain

• Corpus is the larger of the (2) structures

Split-Brain Studies

Purpose: when radical surgery is needed to separate both hemispheres i.e. individuals with severe epileptic disorder

Contribution: demonstrates the functions of each hemisphere and how they separately contribute to our holistic perception of the world.

http://www.youtube.com/watch?v=lfGwsAdS9Dc

For the commissurotomy subject, direct awareness is no longer whole. An object felt in the left hand out of sight cannot be matched to the same kind of object felt separately and unseen in the right hand. As long as the eyes are stationary, something seen just to the left of the fixation point cannot be compared to something seen on the right side. Comparable divisions in olfactory and auditory awareness may be demonstrated. Furthermore, although sight and touch communicate normally on each side, left visual field to left hand or right visual field to right hand, the crossed two-hemisphere combinations fail, as if experiences of eye and hand were obtained by separate persons.

Functions:

-Verbal Abilities

-Mathematical Abilities

-Analytic Analysis

-Recognition of Self

Functions:

-Nonverbal (verbal abilities are very “elementary”

-Spatial abilities

-Holistic (facial expressions/situational cues

-Recognizing others

ENDOCRINE SYSTEMWhat is it?:

The endocrine system is an information signal system much like the nervous system. Hormones regulate many functions of an organism, including mood, growth and development, tissue function, and metabolism.

Why know it?:

Similar to the central nervous system of the body, the glands that make up the endocrine system release hormones into the bloodstream that have profound effects on human behavior.

ENDOCRINE SYSTEM• Endocrine System

– Made up of numerous glands that are located throughout the body. Glands secrete various chemicals called hormones.

• Pituitary• Pancreas• Thyroid• Adrenal glands• Gonads

ENDOCRINE SYSTEM1. Pituitary gland

– hangs below the hypothalamus– divided into anterior and

posteriora. Posterior– rear portion– regulates water and salt

balanceb. Anterior– front portion– regulates growth through

secretion of growth hormone– produces hormones that

control the adrenal cortex, pancreas, thyroid, and pancreas

ENDOCRINE SYSTEM2.Pancreas

– regulates the level of sugar in the bloodstream by secreting insulin

3.Thyroid– located in the neck– regulates metabolism through

secretion of hormones

4. Adrenal glands

–adrenal cortex (outside part): secretes hormones that regulate sugar and salt balance

–adrenal medulla (inside part):secretes two hormones that arouse the body to deal with stress and emergencies

1.epinephrine (adrenaline)

2.norepinephrine (noradrenaline)

ENDOCRINE SYSTEM

5. Gonads– Females

• ovaries produce hormones that regulate sexual development, ovulation, and growth of sex organs

– Males• testes produce

hormones that regulate sexual development, production of sperm, and growth of sex organs

Overview

• By understanding and applying the contributions of both the CNS, PNS and the Endocrine System, a great percentage of human behaviors can be understood as well as their underlying causes.

incredible nervous system

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