Biological Basis Flashcards
1
Q
What is the mind versus body debate?
A
A debate over whether the the mind and the brain are seperate and distinct entities or the same thing.
2
Q
What did most Greek philosophers believe in the mind vs body debate?
A
That the mind and body (brain) were seperate entities and that the mind controls the body but the body cannot control the mind.
3
Q
How long was the Greek philosophers view popular?
A
It was popular for about 2000 years until French philosopher Rene Descartes in the 17th century
4
Q
What did Rene Descartes believe?
A
That the mind is a non-physical entity (soul) that is seperate form the physical fleshy structure of the brain (matter). He agreed that the mind and body were different things
5
Q
What was Descartes belief called?
A
Dualism
6
Q
How did the mind and body come into contact?
A
Through the pineal gland which allows the mind and the brain to interact to produce thoughts, feelings, sensations and conscious experiences. He thought that the mind could affect the brain and visa versa.
7
Q
How has Descartes been proven wrong?
A
The pineal gland is a small structure in the centre of the brain that is part of the endocrine system not the nervous system.
8
Q
What is the endocrine system?
A
A system of glands that secrete hormones into the bloodstream.
9
Q
Who did the split brain experiments?
A
Sperry
10
Q
What happened in the surgery of the split brain experiment?
A
The corpus callosum was cut (the bridge of nerve fibres connecting the two hemispheres)
11
Q
What happened in terms of impairment to the patients in Sperry’s experiment?
A
Generally the suffered little to no impairment but there were some irregularities.
12
Q
Where is information the left visual field processed?
A
The right hemisphere
13
Q
Where is information in the right visual field processed?
A
In the left hemisphere
14
Q
What was the method of the sperry experiment?
A
A patient looked at a black dot in the middle of a screen. A picture of a spoon was flashed to the right or left of the dot.
The patient was unable to say what the object was when it was seen in the left visual field but they could feel for it with their left hand and locate the correct object.
15
Q
What are the results of the Sperry experiment?
A
When a patient sees something in the left visual field (processed by the right hemisphere) the patient was unable to say the name of the object. This was because information was unable to travel from the right hemisphere to the left hemisphere (where speech processing is located) without the corpus callosum.
16
Q
What is the conclusion of the Sperry experiment?
A
The corpus callosum has a vital role in language and speech. It shows support for specialised functions in different hemispheres: left hemisphere specialises in language and right is involved in non-verbal visual tasks.
17
Q
What are some brain recording and imaging techniques?
A
CT Scan, PET and MRI
18
Q
What does CT stand for? When is it used?
A
Computerised tomography. When you can’t use an MRI
19
Q
Who preforms a CT scan?
A
A radiologist
20
Q
What is a patient injected with for a CT scan and why?
A
A substance called contrast (iodine based) which is absorbed by blood vessels and makes it easier to identify brain structures.
21
Q
How does a CT scan work?
A
At each position it sends a small amount of radiation (X-rays) through the skull and brain creating a cross sectional image. Adjacent slides can be combined to create a 3D image
22
Q
What are the benefits of a CT scan?
A
It is extremely useful at showing damage or abnormalities in brain structures. Shows soft tissues eg. Tumors better than an X-ray. It is more clear that an X-ray.
23
Q
What are limitations of a CT scan?
A
It does not provide information about brain function, it involves using powerful X-rays and can not be repeated for several months. It is not as clear as a MRI and is slightly invasive because of the injection of contrast.
24
Q
What is the output of a CT?
A
Structure
25
What does PET scan stand for? What is its output?
PET means Positron Emission Tomography. It's output is function. It's provides information about the levels of activity in different areas of the brain surfing certain tasks.
26
What substance is injected into a patient of taken orally? Why?
A radioactive substance that is glucose. It emits signals that that are detected by a sensitive device and recorded in the PET computer.
27
How does the radioactive substance for PET work?
More active brain areas require increased blood flow as there is more neuronal activity. The increased blood flow means that more radioactive substance is sent to that brain area, emitting stronger signals that less active brain areas.
28
What are PET scans and what do they look like?
The images are compiled to make a coloured map of brain activity.
29
What are the benefits of PET scans?
They provide detailed information about brain function. Researchers can understand which areas are active during certain tasks, it can be used on healthy participants.
30
What are limitations of PET scans?
It is mildly invasive (injected substance), it can only be done of a person a number of times because of the radioactive agent, images are not clear about structure, radioactivity decays quickly so investigation must be short, pictures are taken every 40 seconds so it doesn't pick up rapid progression of the brains activity.
31
When are PET scans used?
When you want to see the functioning of the brain for short tasks.
32
What does MRI stand for? What is the output?
Magnetic Resonance Imaging. It is structure.
33
How does an MRI work?
A patient enters a large chamber and lies very still. Large magnets create a magnetic field which vibrates atoms in the brains Neurons. A computer processes the vibrations. Different types of tissue respond differently to the magnetic field. The computer senses these differences.
34
What are benefits of an MRI?
It allows for precise location of structural damage in the brain. It is non invasive (no X-rays, injections or radioactivity), provides a high quality photo that can be seen horizontally, vertically and sideways. It is clearer than a CT scan.
35
What are limitations of MRI scans?
Cannot be used on people with metallic devices (pacemakers), requires a patient to lie very still (small movements may cause ghosting in the scan), cannot be used on uncooperative or claustrophobic patients.
36
When is an MRI used?
When you want to see a highly detailed image of the brain.
37
What part of the body is the master of information?
The brain, it is the processing and decision making organ.
38
What does the brain do with neural messages?
It receives and interprets information from the sensory systems and sends motor messaged out to all parts of the body so that a co-ordinated and appropriate response can be made.
39
What is the spinal cord and where is it?
It is a complex cable or tract of nerve fibres stretching form the base of the brain to the lower back.
40
How does the spinal cord act like a connection?
It connects the brain to other parts of the body via its connection to the peripheral nervous system. It is like an information super highway.
41
The spinal cord receives...
Sensory information from the peripheral nervous system and transmits it to the brain.
42
The spinal cord transmits....
Motor messages from the brain to the PNS
43
What happens if there is damage to the spinal cord?
It may mean that the motor messages can no longer reach the muscles in the body and that sensations in these muscles will not be registered.
44
What are the specifics of when the spinal cord is damaged?
The brain loses the ability to send motor information to the muscles, organs and glands AND receive sensory information from sensory receptors.
45
How does the severity of paralysis to the body because of spinal cord damage change?
It depends where the spinal cord is damaged and how badly it is damaged.
46
What are sensory Neurons?
They are specialised cells that receive information from outside and inside the body.
47
How do sensory neurons react to a stimulus?
They detect and respond to specific information. They transmit information to the central nervous system. Information is received from the external environment via the sense organs and from internally within the body from muscles, organs and glands.
48
How is the structure of a sensory neuron different?
It contains a sensory receptor to receive incoming sensory information.
49
What are sensory Neurons also called?
Afferent neurons
50
What do motor neurons do?
The transmit messages from the CNS to the muscles, glands and organs. Motor neurons enable muscles to move, cause glands to secrete chemicals and activate organs.
51
How are motor neurons different to other neurons?
Their axon is covered in myelin sheath. This allows motor neural impulses to travel faster.
52
What are motor neurons also called?
Efferent neurons.
53
Where are interneurons located?
Only within the CNS
54
What do interneurons do?
They carry and integrate messages between sensory and motor neurons as motor and sensory neurons don't send messages to each other.
55
What is a soma?
Also called the cell body and it is the structure that determines whether the neuron will be activated and thus transmit messages to other neurons.
56
What is a dendrite?
From the Greek work meaning tree. It is a short, thin, widely branching nerve fibre that detects the receives neural information.
57
What is an axon?
A single tube like, fluid filled detention that transmits messages from the soma to other cells in the body including other neurons, muscles, organs and glands. It is encased in myelin sheath.
58
What is myelin sheath?
A white fatty substance that helps speed up transmission of neural impulses. It insulates the axon.
59
What are axon terminals?
At the end of each axon there are branches called axon terminals.
60
What are synaptic knobs or terminal buttons?
They are small knob-like swelling structures at the tip of axon terminals. It stores chemicals neurotransmitters.
61
What are neurotransmitters?
They are chemicals that assist with the transmission of neural information from one neuron to another across synapses.
62
What is the peripheral nervous system comprised of?
All parts of the nervous system, excluding the brain and spinal cord.
63
What is the peripheral nervous system's two main functions?
To carry sensory information from the sensory organs and internal organs to the CNS (sensory function) and to convey information from the CNS to the muscles, organs and glands (motor function).
64
What are the two branches of the PNS?
The somatic nervous system and the autonomic nervous system.
65
What is the main role of the somatic nervous system?
Control all voluntary movement of the skeletal muscles by carrying sensory information from outside the body to the spinal cord and carrying motor information from the spinal cord to the muscles, organs and glands.
66
What are skeletal muscles?
Those connected to bones
67
In gone SNS what carries sensory information?
Afferent neurons
68
In the SNS what carries motor messages?
The efferent neurons
69
What does the autonomic nervous system do?
It is a network of nerves that carry neural messages between the CNS and involuntary muscles (smooth, non-skeletal called visceral), internal organs and glands. It regulates or controls the functioning of internal organs automatically. It is also responsible for keeping our internal functioning at a stable level and preparing our bodies to deal with threatening situations.
70
What is visceral?
Muscles that are smooth, involuntary and are not skeletal.
71
What is the body maintaining a calm internal environment called? What is our body preparing for threats called?
Homeostasis. Fight of flight
72
What are the branches of the autonomic nervous system?
The parasympathetic nervous system and the sympathetic nervous system.
73
What is the sympathetic nervous system?
It prepares muscles and organ and makes resources available during times when we are faced with threats. This is the fight of flight response. It helps us to physically respond effectually.
74
When does the sympathetic nervous system dominate?
When a person is highly aroused, emotional of requiring a burst of energy.
75
What are some changes that happen when the sympathetic nervous system dominates?
Dilates pupils, inhibits salivary gland secretion, relaxes bronchi in lungs, accelerates heart, inhibits activity of the stomach, intestines and pancreas, stimulates glucose to release from the liver, inhibits gallbladder, stimulates adrenal medulla, inhibits emptying of bladder, promotes ejaculation and vaginal contractions.
76
What are some changes that take place when the parasympathetic nervous system dominates?
Constricts pupils, stimulation of salivary gland, constricts bronchi, slows heart, stimulates activity in stomach, intestines, pancreas and gallbladder, stimulates emptying if the bladder, promotes erection of genitalia.
77
How much does the brain weigh, what is it encased in, what is its consistency and what is it covered in?
It is 1.5 kg, it is encased in a hard skull, is is like firm jelly, it is covered in a strong plastic-like membrane.
78
What neurons does the brain contain?
Billions and trillions of connections between neurons.
79
How is the brain divided and what is its outer surface like?
It is divided into two halves and is convoluted (folded)
80
Where is the hindbrain located?
At the base of the brain around the brain stem.
81
What does the hindbrain do and what does it contain?
It is a collection of lower brain structures that include the cerebellum, medulla and pons. It has control over various motor functions and vital automatic responses such as breathing, heart rate, sleep and arousal.
82
Where is the cerebellum located and what does it look like?
It is at the base of the brain and is cauliflower shaped, about the size of a tennis ball in adults brains.
83
What does the cerebellum control?
Fine muscle movements and regulates posture and balance. It organises and adjusts (doesn't initiate) muscle activity to help ensure that movement is smooth and precise.
84
When is the cerebellum most active?
When you learn a new movement.
85
What can damage to the cerebellum cause?
Difficulty to coordinate muscles and problems with balance.
86
What is the medulla?
It controls vital bodily functions such as swallowing, breathing, heart rate, blood pressure, vomiting, salivating, coughing and sneezing, all of which occur automatically.
87
What does damage to the medulla cause?
It can be fatal. Some parts of the medulla are involved in sensations such as touch, pressure and vibration.
88
What is the pons?
It is involved in sleep, dreaming and arousal from sleep, as well as helping control breathing and coordination of some muscle movements.
89
How can the pons be described as a bridge?
It connects parts of the brain with one another by relaying messages between the cerebral cortex and the cerebellum and between the medulla and the midbrain.
90
What is the midbrain?
It contains neural pathways connecting upper and lower brain areas. It is a collection of structures involved in movement, processing of visual, auditory and tactile sensory information, sleep and arousal. It receives a large amount of information from the eye and ears and processes this to help other structures which are also involved in movement, particularly limb movement.
91
What is the forebrain? What does it contain?
The largest and most prominent part of the brain. It includes the hypothalamus, thamalus and cerebrum. It regulates complex cognitive processes such as thinking, learning, memory and perception as well as aspects of emotions and personality.
92
What is the cerebral cortex? What is it involved in?
The outer layer of the brain. It is the largest part of the brain and has 75% of neurons in the brain. Only 1/3 is visible. It is 3-5 mm thick. It is involved in higher order functioning such as speech, problem solving, memory, learning, perception and planning.
93
How is the cerebral cortex divided?
In to two hemispheres left and right.
94
How are the hemispheres divided?
By the corpus callosum.
95
What is the corpus callosum?
It is a bridge of nerve fibres that allow information to pass between the two hemispheres.
96
What is hemispheric dominance and specialisation?
There is evidence bag suggests that one hemisphere is dominant, but hemispheres do not function independently. Each hemisphere has specialised roles known as hemispheric specialisation.
97
What is the left hemisphere involved in?
Language and skills (reading, spelling, writing) -Broca's and Wernickes, logical thinking, sequential processing (in order), problem solving, analysing, judging time and rhythm. It controls voluntary movement of and receives sensory information from the right side of the body,
98
What is the height hemisphere involved in?
Non-verbal/visual skills (drawing, pictures, faces), visual spatial skills (recognising patterns, reading maps), simultaneous and holistic processing (at the same time), appreciation (beauty, art), fantasy, dreaming, creativity, recognising emotions, understanding context if language, global focus. It controls voluntary movement of the left side of the body and receives sensory info from the left side.
99
What four lobes is the cerebral cortex divided into?
Frontal, parietal, occipital and temporal.
100
Where is the frontal lobe and how does it compare in size to other lobes?
It is the largest lobe, occupying the upper forward half of each hemisphere, behind the forehead.
101
What located in the rear of the frontal lobe?
The primary motor cortex and Broca's area
102
What are the functions of the frontal lobe?
The frontal lobe association area is involved in judgement, thinking, planning, abstract reasoning, personality, control and expression of appropriate emotional reactions and attention.
103
What is the primary area of the frontal lobe? What does it do?
The primary motor cortex. It controls voluntary movements of skeletal muscles (muscles that can be moved voluntarily and are connected to the skeleton).
104
How is the primary motor cortex organised?
The PMC in the left frontal lobe controls voluntary movement of the right side of the body and visa versa. It is also organised into a motor homunculus.
105
What is a motor homunculus?
It organises the primary motor cortex and different body areas are represented in different areas of the motor cortex. It is organised in that the upper parts of the body are found in the lower parts of the MC and visa versa (inverted). Areas that are used often and are dexterous are represented proportionately bigger. Areas such as the mouth.
106
How are the motor and somatosensory cortexes organised?
Inverted, contralateral (right controls left and visa versa) and homunculus
107
What is the specialised area of the frontal lobe and where is it located?
Broca's area which is located in the frontal lobe but only the left hemisphere.
108
What is Broca's area involved in?
The production of clear and articulate speech. It specifically coordinates the movement of the muscles in the jaw, lips and tongue, all of which are involved in speech.
109
What is damage to the Broca's area called and what does it cause?
This is called Broca's aphasia. The language of someone with Broca's aphasia is impaired and disjointed. It is hard to speak but people with it know they have it.
110
Who is someone who's frontal lobe was damaged and what happened?
Phineas Gage. An iron rod went through his frontal lobe during a railroad accident. His personality changed making the quiet, friendly man arrogant and aggressive. This lead to the belief that the frontal live is involved in personality.
111
Where is the parietal lobe located? When is the primary cortex located?
It occupies the area behind the frontal lobe, in the upper back half of the brain but not the rearmost area. The primary cortex, the primary somatosensory cortex, is separated from the primary motor cortex by a groove (fissure, sulcus)
112
What is the association area of the parietal lobe involved in?
It is involved in monitoring body limb positioning and determining spatial positions of objects in an environment. For this the occur the association integrates information about the limb positioning with visual information from the primary visual cortex and sound from the primary auditory cortex. It is also involved in attention and spatial reasoning (usually in the right hemisphere).
113
What does damage to the right parietal lobe result in?
A condition called spatial neglect or neglect syndrome.
114
What is the primary area of the parietal lobe?
The primary area of the parietal lobe is the somatosensory cortex. Which is located at the front of the parietal lobe and next to the primary motor cortex.
115
What does the primary somatosensory area do?
It receives and processes sensory information from the body senses, particularly taste, touch, temperature, muscle movement, position and pressure.
116
Describe the primary somatosensory cortexes organisation in terms of its homunculus ect.
The primary somatosensory cortex is contralateral. And it's homunculus is inverted. Areas that are very sensitive to touch are represented as larger these areas include, lips, tongue, mouth and genitals.
117
Where is the occipital lobe found and what is it exclusively involved in?
It is found at the rearmost of each hemisphere and is exclusively involved in vision.
118
What could damage to the occipital lobe result in?
Blindness.
119
What is the association area of the occipital lobes role?
To organise and integrate visual information with memory, language and sounds. It does this by interacting with the association areas in the frontal lobe, parietal and temporal lobe.
120
What is the primary area of the occipital lobe? What does it do?
The primary visual cortex. It's role is to receive sensory information from the sensory receptors in the eyes (photoreceptors).
121
How does the field of vision concept relate to the occipital lobe?
The left half of each eye (which receives information from the right visual field) send that information to the left occipital lobe. The right half of the eye (which receives from the left visual field) sends information to the right occipital lobe.
122
Where is the temporal lobe located and where is its speciality area and primary cortex located?
The temporal lobe is located in the lower, central area of the brain, around the top of each ear. The primary auditory cortex is located at the top of the temporal lobe and the Wernicke's area is located adjacent to the primary auditory cortex in the left hemisphere only.
123
What is the association area of the temporal lobe involved in?
Memory (particularly people's faces), object identification and determining appropriate responses to stimuli. It is also responsible for receiving, processing and storing memories of facts, how to do things and personal memories.
124
What is a semantic memory?
Memories of facts
125
What are procedural memories?
Memories of how to do something.
126
What are episodic memories?
Personal memories
127
What is the primary area of the temporal lobe? What does it do, each hemisphere separately?
The primary auditory cortex. It's function is to receive and process auditory information from the ears. The left temporal lobe processes verbal sounds such as words and the right hemisphere processes non-verbal sounds such as music.
128
How can damage to the temporal lobe occur and what are some symptoms of the damage?
It can be caused by a blow to the head of stroke. It can cause an inability to recognise a person as someone you know even though you can determine their sex, facial features and approximate age. The impairments are only in recognising people.
129
What is the specialised area if the temporal lobe called? And what is it involved in?
The Wernicke's area. It is involved in the comprehension of speech, speech production, locating appropriate words from memory to express their meaning.
130
How is the Wernicke's area connected to the Broca's area? And why are they connected?
By a bundle of nerve fibres. Once a word is located in memory a representation of this word is sent from Wernicke's area to Broca's area which coordinates the muscles to say the word.
131
What happens if the Wernicke's area is damaged?
This is called Wernicke's aphasia. Symptoms include the inability to comprehend the meaning of spoken language and having meaningless speech. People don't realise they have it.
132
When are two times of rapid development of the brain? Why do these changes happen?
Infancy and adolescence. They are in build of genetically pre programmed.
133
What is plasticity? Why is it necessary?
The way the brain changes in response to stimulation from the environment, plasticity is necessary for learning to take place throughout a healthy persons lifespan.
134
What are the two types of plasticity?
Developmental and adaptive plasticity
135
What is developmental plasticity? When does it occur?
Changes in neural connections during development. It begins in vitro and ends at about 23 when all neurons are myelinated. Most occurs prenatal and in the first 15 months of life.
136
What is different between adults' and children's plasticity?
An adult's brain generally has less plasticity that a child's. Adults have about 40% less synapses that 3 year olds.
137
What benefits does having a more plastic brain have? (Children)
The brain is able to use other parts of the brain to make alternative connections which can compensate for missing structures or damage to the brain.
138
What is the last part of the brain to develop? Why is this?
The prefrontal cortex (the area responsible for problem solving, planning, impulse control and critical thinking). There is an increased amount of pruning between 16 and 20 years.
139
When does developmental plasticity end?
When all neurons are myelinated.
140
What is synaptogenesis occur and what is it?
It occurs during developmental plasticity and occurs most rapidly in the first 15 months of life. It is the formation of new synapses between neurons. It is caused by dendrite brushing and sprouting increasing potential synaptic connections.
141
What is synaptic pruning? Why and when does it occur?
More connections are made in the 2 first years if life that will ever be used. Weak or unused synapses are pruned (killed off). Pruning occurs mostly at 3 years and then at adolescence. It assists in more efficient functioning of neural activity.
142
What is adaptive plasticity? Why does it happen?
Neural changes to enable adjustment to experience (leaning), compensate for lost function and/or maximise remaining functions in the event of brain damage. It can occur at anytime in life but is more substantial and extensive in infancy and childhood.
143
How can brain deficits occur?
From birth or as a result of brain damage.
144
What is reorganising if re-routing? When does this happen?
The functions from damaged areas are relocated to areas that are undamaged. When neurons re-route old connections and form new connections in undamaged areas. This is more likely to happen until the age of three.
145
What is damage to the brain?
Brain injury is any damage to the brain that impairs normal functioning either temporarily or permanently.
146
What are frontal lobe damages?
Phineas Gage (changed personality), lobotomies (removal of frontal lobe to treat mental illness), Broca's aphasia (stuttering).
147
What is parietal damage?
Spatial neglect. Happens in the right hemisphere. Sufferers act although their left side and left world doesn't exist. They fail to attend to that side and may only shave one side if their face ect. It is a problem with attention not vision. In bad cases they might just say the right half of a compound eg basketball becomes Ball.
148
What is occipital lobe damage?
Agnosia or loss of knowledge. People lose ability to recognise objects, persons, sounds, shapes or smells while the sense is not defective and there is no significant memory loss. The man who mistook his wife for a hat (Oliver Sacks Case study)
149
Temporal lobe damage
Wernicke's aphasia.
150
What is Parkinson's disease?
A neurological disorder with symptoms including tremors, rigidity (stiff muscles), slowness of movement, shuffling steps, decreased fine motor movements, bradykinesia, balance problems, speech and swallowing problems, pain and discomfort, psychological: confusion, depression, slowed thinking, impaired, memory and decision making.
151
What are the causes of Parkinson's disease?
Progressive degeneration of the substantia nigra (in the midbrain), this part of the brain is involved in the coordination and regulation of smooth movement, balance and walking, low levels of neurotransmitter Dopamine, not genetic, age is the greatest factor
152
Who gets PD and how many have it?
It mainly affects people between 50-75, 20% of cases are diagnosed between 30-50 and more that 30000 Australians have been diagnosed.
153
How can PD be diagnosed?
No blood test can detect it, by looking at gradual deterioration of functions
154
How can PD be treated?
There is no known cure, it is not contagious, lifespan is not shortened, medications can be used to decrease symptoms eg. L-dopa and deep brain stimulation.
