| Question | Answer |
| Impairment in the frontal lobes can result in... | Loss of simple / complex movement
Loss of ability to spontaneously interact
Loss of flexible thinking / problem solving
Perseveration
Inability to focus on a task
Mood changes
Changes in personality / social behavior
Inability to speak |
| Impairment in the temporal lobes can result in... | Difficulty recognizing phases (prosopagnosia)
Difficulty understanding spoken words
Poor selective attention (verbal / visual)
Short-term / long-term memory loss
Increased aggressive behavior
Inability to categorize objects
Persistent talking |
| Impairment in the parietal lobes can result in... | Inability to attend to more than one object at a time
Problems w/ reading (alexia)
Difficulty writing words (agraphia)
Word blindness (inability to recognize words)
Difficulty w/ math (dyscalculia)
Unilateral neglect
Impaired perception of touch |
| Impairment in the occipital lobes can result in... | Visual field cuts
Difficulty locating objects in the env
Difficulty recognizing movement
Difficulty recognizing colors
Visual illusions
Difficulties reading / writing
Word blindness |
| Insula | Portion of the cerebral cortex (fifth lobe)
Located underneath parietal, temporal & frontal lobes, deep w/in lateral fissure of cerebral cortex
Visceral area for sensory / motor function related to speech & language skills |
| Cerebellum | Inferior to occipital lobes & posterior to brainstem
Comprised of 2 hemispheres / divided into 3 lobes each
White matter connects to other parts of CNS
Gray matter analyzes body movements - crucial for balance / coordination + automatic motor skills |
| Cerebral blood flow | Brain receives blood supply from carotid & vertebral basilar arteries |
| Carotid system | Consists of left / right branches
Divides into internal / external carotid arteries
Internal carotids supply blood to brain & divide into: ACA, MCA, PCA |
| ACA | Anterior cerebral artery
Supplies forebrain |
| MCA | Middle cerebral artery
Supplies forebrain |
| PCA | Posterior cerebral artery
Supplies posterior cortex, midbrain, brainstem |
| Circle of Willis | Located at base of brain
Arterial systems join here
Allows blood to flow through both brain hemispheres
Safety valve if blood to brain is blocked on one side |
| CVA | Cerebral vascular accidents
Occurs when there is a lack of blood flow to any area of brain including brainstem
3rd most common cause of death in U.S. - 33% mortality rate
Leading cause of disability in U.S.
550k strokes occur annually |
| Ischemic CVA | Comprise 80% of strokes
4 subtypes: 1. large artery atherothrombotic, 2. small artery / lacunar stroke, 3. embolic stroke, 4. dissection stroke |
| Hemorrhagic CVA | Comprise 20% of strokes - 50% mortality rate
Identified by location & subtype: 1. intracerebral (inside brain), 2. extracerebral intracranial (outside brain, inside skull)
Blood vessel bursts in brain causing blood to enter surrounding tissue |
| Causes of hemorrhagic stroke | Brain herniation, massive edema, cocaine / drugs, aneurisms (majority), leukemia, clotting deficiency, diet pills, brain tumors
Occurs more in women 50-60 years old |
| Causes of ischemic stroke | Male gender, age, family history, hypertension, diabetes, prior TIAs, smoking, excessive alcohol, birth control pills, sedentary lifestyle |
| Types of ischemic stroke | Thrombus - collection of fat / blood from diseased artery that narrows it & blocks flow of blood going to brain
Embolism - blood clot containing arterial debris that travels to smaller artery & gets stuck thereby block flow of blood to brain |
| CNS | Central Nervous System is comprised of the brain & spinal cord
Each segment of the spinal cord has sensory / motor nerves that innervate the skin, organs & muscles of the body
Substantial loss of neurons often leads to disability |
| Brain hemispheres | Right / left hemispheres separated by longitudinal fissure comprised of 2 large bundles of axons known as the corpus callosum
2 hemispheres receive sensory info from the contralateral side of the body & effect movement on the opposite side |
| Hemiparesis | Weakness on one side of the body |
| Hemiplegia | Paralysis on one side of the body |
| Damage to brain hemispheres | Can result in paralysis or loss of sensation
left side - generally results in right sided damage
right side - generally results in left sided damage |
| How does the brain receive its blood supply? | From carotid & vertebral basilar arteries |
| Sensory neurons | sensors that are sensitive to light, sound, touch, temperature, smell & chemical input |
| Motor neurons | actors that receive excitation from other cells giving rise to muscle impulses & secretion of hormones |
| Interneurons | connect one neuron to another & can notify motor neurons to move a part of the body that has detected dangerous sensory info |
| Describe neuron structure | Each neuron has a body (soma), filamental extensions (dendrites) & longer fibers (axons) |
| Describe neuron function | Neurons communicate w/ each other via dendrites & axons
Dendrites receive stimuli from other neurons
Axons send stimuli to other neurons, glands & muscles
Transmission occurs via electromechanical neurotransmitters |
| Describe the neuron synapse | The bulb of the axon makes contact w/ the dendrite at the synapse. This is where the brain does its work to move, breathe, think & feel |
| Describe the chemical event at the synapse | Action potential reaches the tip of the axon (end bulb) & releases a chemical (neurotransmitters) into the synaptic cleft
Chemical is diffused across the cleft & interacts w/ a receptor on postsynaptic membrane giving rise to excitation or inhibition |
| What do neurotransmitters stimulate? | Dendritic endings |
| How does the neural impulse occur? | Through a change in electrical current across the cell membrane & nerve fibers |
| What is the function of the autoreceptor? | At the synapse, the autoreceptor acts as a synaptic thermostat & determines if more or less of a neurotransmitter is needed |
| What is the function of the reuptake transmitter? | At the synapse, the reuptake transmitter acts as a revolving door to re-use the neurotransmitter |
| What happens at the synapse? | Neuron releases a combination of neurotransmitters
Some neurotransmitters excite & others inhibit transmission to adjacent neurons |
| Describe the function of neurotransmitters | Chemical part of electrochemical conduction
Approx 40-50 types
Assist in regulation of brain's ability to control speech / language, motivation, pain, stress, cravings, personality, mood, attention, memory, metabolic functions, etc. |
| 3 primary substance groups of neurotransmitters | 1. amino acids (major neurotransmitters of brain), 2. peptides (special functions in hypothalamus), 3. monoamines (modulating functions in brain) |
| Amino acids | glutamate, GABA, aspartic acid, glycine |
| Peptides | vasopressin, somatostatin, neurotensin |
| Monoamines | epinephrine, norepinephrine, dopamine, serotonin, melatonin, acetylcholine |
| "Feel good" neurotransmitters | endorphins (mood)
norepinephrine (excitation, alertness, arousal, motivation, panic)
dopamine (cognition, motivation, pleasure, appetite control)
acetylcholine (alertness, sleep-wake cycles, memory, growth, sex)
phenylethylamine (infatuation) |
| Inhibitory neurotransmitters | enkephalins (restricts pain, reduces cravings / depression)
GABA (anti-stress / anxiety / panic / pain, promotes calmness & focus) |
| Hormonal neurotransmitters | serotonin (mood regulation, promotes sleep, improves self-esteem, lessens worry / depression)
melatonin (rest / recuperation, anti-aging, body clock regulation)
oxytocin (stimulated by dopamine to promote sex & emotional attachment) |
| Weight of human brain | Birth = 350 grams (12 oz)
1 year old = 1,000 grams (2.2 lbs)
Adult = 1,200 - 1,400 grams (2.6 - 3.1 lbs) |
| Describe the coverings of the brain | 3 layers of tissues known as meninges protect the brain
1. dura mater
2. arachnoid membrane (subarachnoid space contains blood vessels & CSF)
3. pia mater |
| CSF | cerebrospinal fluid is the clear fluid that circulates throughout the brain & spinal cord, cushioning & protecting them from injury
Flows from one ventricle to the next then into subarachnoid space |
| Describe the brain ventricles | 4 ventricles total: 2 lateral, 3rd ventricle, 4th ventricle
Lateral = located in interior hemispheres of forebrain, connect w/ 3rd ventricle at posterior point which connects to 4th ventricle at medulla |
| What do the ventricles contain? | ventricles & the central canal of spinal cord contain CSF - within each ventricle the choroid plexus produces CSF
This is fluid-like blood plasma formed by cells in the 4 ventricles |
| Hydrocephalus | occurs when the flow of CSF is obstructed & accumulates in ventricles or subarachnoid space thereby increasing pressure on the brain
children - this condition causes bones in head to spread (head becomes large) |
| What is the function of the cerebral cortex? | involved in primary sensory, primary motor & association area functions
complex thinking, learning, personality, movement, touch, vision |
| Describe the structure of the cerebellum | also known as cerebellum, largest part of the brain
divided into left / right hemispheres
composed of gray matter or cell bodies totaling 6+ billion w/ dendritic connections |
| What is the function of association areas in the cerebral cortex? | to connect sensory & motor areas, give humans the ability to integrate & interpret daily events |
| What is the function of sensory areas in the cerebral cortex? | to get input from the environment, including touch, taste, smell, vision, hearing |
| What is the function of motor areas in the cerebral cortex? | to permit movement in response to needs / wants |
| What is the function of gray matter? | to direct sensory or motor stimuli to the interneurons of the CNS for responsiveness via synaptic activation |
| What does gray matter contain? | nerve cell bodies, glial cells, capillaries, axons, dendrites |
| What does white matter consist of? | axons that travel throughout the cortex (internal capsule)
refers to color of the myelinated sheaths that wrap each axon
consists of lipids or fatty material |
| Multiple sclerosis destroys the | myelin sheath surrounding the axons |
| Left hemisphere | typically best at processing speech & language
involved in verbal memory |
| Right hemisphere | typically best at processing paralinguistic information, pragmatics, non-linguistic information that is visual, spatial, musical, emotional |
| The corpus callosum is critical to | transmission of information between left / right hemispheres |
| Lobes of the brain | each hemisphere is comprised of 4 lobes: frontal, temporal, parietal, occipital |
| Frontal lobe | most anterior part of the brain
control of movement, planning / initiating, concentration, emotional responses, disinhibition of behaviors, switching sets to adapt to changes
conscious awareness
expressive language
Broca's area (speech production) |
| Temporal lobe | located laterally in the cerebral hemispheres
left temp lobe contains Wernicke's area (lang comprehension)
balance, comprehension of language, hearing ability, categorization of skills, some visual perception |
| Parietal lobe | located b/w occipital lobe & central sulcus |
| Occipital lobe | posterior part of the brain
receives projections from thalamus via optic nerve & sensory info from eyes
retina gets visual input from light, shapes, shading |
| Hemianopsia | visual field cut
results from damage to visual cortex |
| Scotoma | small blind area
can result from small area of damage in left hemisphere |
| What is the function of the brainstem? | connects brain to spinal cord & regulates primary life functions: breathing, respiration, swallowing, blood pressure, eye movements, heart rate, vomiting, salivation, sneezing, coughing, gagging |
| What does the brainstem consist of? | Medulla oblongata, pons, midbrain |
