Lecture 4: Brain Anatomy and Physiology Flashcards
When does the anterior fontanel close on babies?
18 Months (according to Valley)
When does the posterior and the anterolateral fontanel close?
2 months (Valley review)
When does the Posterolateral fontanel close?
2 yrs - This one takes the longest. (Valley Review)
What information does the Cerebrum process?
Somatic sensory and motor information
The cerebrum has 2 hemispheres - each is divided into _____ lobes
Four
What are the 4 lobes of the Cerebrum?
Frontal, Parietal, Temporal, Occipital
What are some of the functions of the Frontal Lobe?
Memory formation, Emotions, Decision making/reasoning, Personality
Where is the Primary Motor Cortex and what is it responsible for?
Located in Precentral Gyrus, involved with coordinating movements of the body
Where is Broca’s area and what does it control?
Found in the LEFT Frontal Lobe - Controls facial neurons, speech, and language comprehension
What could be the result of damage to Broca’s Area (Broca’s Aphasia)?
Ability to comprehend but inability to speak or form words
What is the site for Frontal Lobotomies?
Orbitofrontal Cortex
What is the name of the area that houses Cranial Nerve I?
Olfactory Bulb
Summary of Frontal Lobe functions
Speech, Emotion/mood/personality, Problem solving, Movements, Judgement
What are the main functions of the Parietal Lobe?
Spatial Awareness - proprioception, hand-Eye movement:::Senses and integration of senses
In the Parietal lobe, the Primary Somatosensory Cortex (postcentral Gyrus) is responsible for what?
Processing tactile and proprioceptive information
In the Parietal lobe, the Somatosensory Association Cortex is responsible for what?
Integration and interpretation of sensations relative to body position and orientation in space. May assist with visuo-motor coordination
In the Parietal lobe, what area is responisble for taste?
Primary Gustatory Cortex
Damage to the Parietal Lobe can cause problems such as
Inability to attend to more than one object at a time. Inability to name an object (anomia). Problems with reading (Alexia). Difficulty drawing objects. Difficulty distinguishing Left from Right. Difficulty doing math (Dyscalculia). Difficulty judging spatial awareness (apraxia). Inability to focus visual attention. Difficulty with Hand/Eye coordination
Visual Information and interpreting of visual information takes place in what lobe?
Occipital lobe
What are some issues one might face if they have damage to the occipital lobe?
Defects in vision and visual field cuts. Difficulty with colors (color agnosia). Hallucinations and illusions. Inbility to recognize words or drawn objects. Difficulty reading/writing
What are some of the primary roles of the temporal lobes?
Hearing. Organization and comprehension of language. Information retrieval (memory and memory formation)
In the temporal lobe, what is the Primary auditory Cortex responsible for?
hearing
In the temporal lobe, what is the funciton of the Primary Olfactory Cortex?
Interprets smell information received from the Olfactory Bulb
In the temporal lobe, what is Wernicke’s Area responsible for?
Language comprehension and is located in the LEFT temporal lobe
If someone is experiencing Wernicke’s Aphasia, what symptoms do they likely exhibit?
Can’t comprehend language and likley can’t form sentences or they might make nonsensical sentences
What is the Arcuate Fasciculus?
white matter tract that connects Broca’s and Wernicke’s areas
Damage may result in Conduction aphasia - ability to comprehend but difficulty repeating what was heard
Some observed problems from damage to the temporal lobe might include:
Difficulty in recognizing faces (Prosopagnosia).
Difficulty in understanding spoken words.
Disturbance with selective attention to what we see and hear.
Difficulty with identification of, and verbalization about objects.
Short-term memory loss.
Interference with long-term memory
Inability to categorize objects (Categorization).
Right lobe damage can cause persistent talking.
Increased aggressive behavior.
In the Humunculus, why are there some parts of the body that are so out of proportion to the size of the body part?
Means the parts have more or less sensory or motor input
What are some of the functions of the Cerebellum?
Provide precise timing for body movement
Adjust posture
Balance and equilibrium
Cerebellar activity is done subconsciouslyProvides precise timing and appropriate patterns of skeletal muscle contraction to coordinate repetitive body movements and assist learning of complex motor behaviors
Adjusts the postural muscles of the body, controls balance and equilibrium
Recognizes and predicts sequences of
Cerebellar activity occurs subconsciously
Provides timing and coordination of muscle activity
Adjusts posture, controls balance and equilibrium
Recognizes and predicts sequences of events
Cerebellar activity occurs subconsciously
Cerebellar lesions can cause what kinds of problems?
Asynergia - lack of muscle coordination
Ataxia - lack of organized movement
Hypotonia
Asthenia - reduced muscle strength
What are some of the autonomic functions controlled by the Medulla Oblongata?
Arousal
heart rate
blood pressure
pace for respiration and digestion
What cranial nerves are associated with the Medulla Oblongota?
CN IX, X, XI, XII
What are some of the control centers present in the Medulla Oblongota?
Cardiovascular control center - force and rate
Respiratory center - rate and depth
Vomiting, hiccupping, swallowing, coughing, and sneezing
What is the major control center located in the Pons?
Pneumotaxic Center - controls respiration
Which cranial nerves are associated with the Pons?
CN V-VIII
What is the function of the midbrain?
Process sight, sound and associated reflexes
Maintains Consciousness (reticular formation)
Where is the Diencephalon and what does it connect?
located under the cerebrum and cerebellum. Links the cerebrum with the brainstem
What is the major function of the diencephalon?
Integrate sensory information with motor commands
What cranial nerve is associated with the diencephalon?
CN II (optic)
Name three parts of the diencephalon
Pineal Gland - Thalamus - Hypothalamus
What hormone is secreted by the Pineal gland?
Melatonin
What is the primary funciton of the Thalamus?
Sensory relay station - all sensory information stops here first EXCEPT for smell
What are some of the primary functions of the hypothalamus?
“Captain of the ANS, master overseer of homeostasis”
- emotions and behavior: Mediates pleasure, fear, rage
- regulation of body temp, BP, GI motility, rate and depth of resp and other visceral activities
- Drives food intake
- water balance, thirst
- day/night rhythms
- Endocrine: secretes ADH and Oxytoccin
What is the function of the pituitary gland?
It is a Major endocrine gland - controls all others
How are the Hypothalamus and Pituitary connected?
the Infundibulum
What is the function of the basal ganglia?
accessory motor system that helps control complex patterns of activity like writing, using scissors, suturing and throwing a ball
How much CSF is formed per day?
500 ml/day or about 21 ml/hr
How much CSF does a normal adult have?
150ml
From the Choroid plexus to the arachnoid villi, name the pathway the CSF will take (10 steps) Valley pg 94
- Choroid plexus
- Lateral ventricles
- Foramen of Munro
- Third Ventricle
- Aqueduct of Sylvius
- Fourth ventricle
- Foramen of Lushka and Magendie
- Subarachnoid space of spinal cord
- Brain
10 Arachnoid Villi
Abbreviated CSF pathway
ventricles –> arachnoid space –> dural sinuses and back to circulation
What is the site of formation and site of reabsorption of CSF?
Formation - choroid plexus
Reabsorption - Arachnoid Villi
What cells line the ventricles and what do they form?
Ependymal cells which help form the choroid plexus
What membrane covers the surface of the brain?
Arachnoid membrane beneath it is the subarachnoid space
how is the Pia Mater anchored to the brain?
with astrocytes - wraps it like Saran Wrap
Where is the subdural space?
Between the dura mater and the arachnoid mater
where is the subarachnoid space and what does it contain?
Between the arachnoid and pia mater. Filled with CSF, contains collagen/elastin fiber network and spiderweb-like arachnoid trabeculae
What are 2 common sites of intracranial bleeding?
Subdural and Subarachnoid spaces
Function of CSF
Cushion, support, and transport
It is like plasma or interstitial fluid but much more pure
