Chapter 20 Part 2 Flashcards
What are the divisions of the brain?
- brainstem: midbrain, pons, medulla
- cerebellum
- diencephalon
- cerebrum
What germ layer does the brain develop from?
-ectoderm
What is the neural tube?
-a hollow structure from which the brain and spinal cord form
What are the primary brain vesicles?
- proencephalon (forebrain)
- mesencephalon (midbrain)
- rhombencephalon (hindbrain)
What secondary brain vesicles does each primary brain vesicle become?
- proencephalon –> telencephalon and diencephalon
- mesencephalon –> mesencephalon
- Rhombencephalon –> metencephalon and myelencephalon
What brain region does each secondary brain vesicle become?
- Tele becomes Cerebrum
- Dien stays Dien
- Mese becomes Midbrain
- Mete becomes Pons and Cerebellum
- Myele becomes Medulla
What is the structure of the brainstem?
- midbrain (superior)
- pons (middle)
- medulla (inferior)
- 10 out of 12 cranial nerves come from the brainstem!!!
What cranial nerves come off the medulla?
-8 through 12
Where are the pyramids located and what information are they important to?
- in the medulla
- important for motor information
What are the functions of the medulla?
-autonomic functions of breathing, heart rate, and blood pressure
What are the reflexes of the medulla?
- vomiting
- coughing
- sneezing
- hiccupping
- swallowing
What other sensations are housed in the medulla?
- touch
- pressure
- vibration
- consciousness
What does the nucleus gracilis do?
-allows sensation in the lower body
What does the cuneate nucleus do?
-allows sensation in the upper body
What special senses are housed by the medulla?
- taste
- sound
- balance
What is the major function of the pons?
- helps control respiration
- links the brain via tracts
What cranial nerves come off of the pons?
-5 through 8
What cavity of CSF is contained by the midbrain?
-cerebral aqueduct
What are the corpora quadrigemina?
- two inferior colliculi
- two superior colliculi
What are the inferior colliculi? What do they do?
-auditory center
What are the superior colliculi? What do they do?
-visual center
What is the substantia nigra? What neurotransmitter does it use? How does it relate to Parkinson’s?
- a black portion in the midbrain
- uses dopamine
- regulates muscular movement so as it goes away tremors begin to occur
What is the red nucleus?
-part of the midbrain that controls coordination of muscular movements
What cranial nerves come off the midbrain?
- 3 and 4
- oculomotor and trochlear
What reflexes is the midbrain responsible for?
- pupillary reflex
- eye movements
What dural folds are associated with the cerebellum?
-tentorium cerebelli
How are the gray and white matter organized in the cerebellum?
- gray is on the outside; folia
- white is the tree on the inside; arbor vitae
What is arbor vitae?
-the tree of life in the cerebellum
What are the functions of the cerebellum?
-planning and coordination of skeletal muscle activity
What do you think would happen if there was an injury to the cerebellum?
-trouble or inability to walk
What is proprioception?
- the unconscious perception of movement and spatial orientation
- ex. knowing that you are in a lying position
Where is the diencephalon?
-between the cerebrum and midbrain
What structures make up the diencephalon?
-thalamus
-hypothalamus
-epithalamus
~pineal gland
What ventricle is surrounded by the diencephalon?
-third ventricle
When I think thalamus, I should think ___________?
-sensory
What are the functions of the thalamus?
- large role in sensation mechanism
- associates sensations with good or bad
- arousal or alert
What are all the functions of the hypothalamus?
- main regulator of homeostasis
- produces hormones (link between nervous and endocrine system)
What are the four main regions of the hypothalamus? Reflexes?
- mammillary region: smell
- tuberal region: pituitary stalk
- supraoptic
- preoptic: autonomic
What joins the hypothalamus to the pituitary gland?
-infundibulum or pituitary stalk
What is the function of the optic chiasm?
-allows the optic nerves to cross each other before entering the brain
What are the differences between the optic nerves and optic tracts?
- the nerves come to the optic chiasm and cross before entering the brain
- the resulting bundle of fibers are called optic tracts
What is the pineal gland? What does it secrete?
-secretes melatonin to regulate the sleep cycle
How are gray matter and white matter in the cerebrum?
- gray is the surface
- white is the grooves
What are gyri?
-the mountains of the cerebrum
What are the important gyri to know?
- precentral gyrus
- postcentral gyrus
- cingulate gyrus
- hippocampal gyrus
What are sulci? Important?
- the valleys of the brain
- shallow
- central sulcus
- parietooccipital sulcus
What are fissures? Important?
- the valleys of the brain
- deep
- longitudinal fissure
- lateral fissure
What are the important lobes to know? Functions?
- frontal lobe: motor, personality, calms agression
- parietal lobe: sensory information
- temporal lobe: hearing
- occipital lobe: vison
- insula: limbic system
What is the corpus callosum?
-the connection between the right and left hemisphere
What are cerebral tracts?
-white matter beneath the cortex
What are the kinds of cerebral tracts?
- projection tracts (ascending and descending)
- association tracts (within the same hemisphere)
- commissural tracts (communication between right and left hemisphere)
Through what structure do commissural tracts run?
-corpus callosum
What are the three basal nuclei we need to know?
- caudate nucleus
- lentiform nucleus
- amygdaloid nucleus
What does the amygdala do?
-fear and threats
What are the overall functions of the basal nuclei?
-a small role in regulating motor function
Where is most somatic sensory information brought to?
-thalamus and then the postcentral gyrus!!
Where is the postcentral gryus located?
-parietal lobe
What is the difference between somatic and special senses?
- somatic: touch, pressure, temp, basically something that you can feel anywhere
- special: vision, hearing, taste, can only happen in a certain place
What is a homunculus?
-two specific regions of the body synapse onto specific regions of the somatic sensory area
How does sensitivity portray in the homunculus?
-more sensitive = more receptors = larger portion of the homonculus
Where is visual information brought to? What number? What lobe?
- primary visual area
- # 17
- occipital lobe
Where is sound brought to? What numbers? What lobe?
- primary auditory area
- # 41 and #42
- temporal lobe
Where is taste brought to? What number? What lobe?
- primary gustatory area
- # 43
- parietal lobe
What is the pathway for somatic sensory information?
-pathway that conducts impulses to from the point of stimulation to the postcentral gryus
Which neurons bring information where?
- primary sensory
- secondary sensory
- tertiary sensory
What does it mean to decussate?
-switching from one side of the brain to the other
Where is motor function brought to? Location?
- central sulcus
- groove between frontal and parietal lobe
What controls speech movement? Number?
- Broca’s area
- # 44
- in left hemisphere
What are two types of motor pathways?
- pyramidal tracts
- extrapyramidal tracts
Where are association areas?
-cerebral cortex
Where is the somatosensory area?
-postcentral gyrus
Where is the visual association area?
- cortical visual area
- 18 & 19
Where is the gnostic area?
-5, 7, 39, & 40
Where is the premotor area?
-6
Where is the frontal eye field?
-8
Where is the auditory association area? What is it called? What is its number?
- temporal lobe
- Wernicke’s area
- # 22
What is aphasia?
-the inability to use of comprehend a words
What is nonfluent aphasia? What is damaged?
- cannot form a word (Daryl)
- Broca’s area
What is fluent aphasia? What is damaged?
- inability to comprehend words (mumbo jumbo)
- Wernicke’s or auditory association area
What is the reticular activating system for?
- how we maintain consciousness
- how we can tell that the smell of cookies are good and the smell of smoke is bad
What is the limbic system responsible for?
- allows us to experience many kinds of emotions
- may also play a role in memory
