Chapter 14 - Brain Flashcards
What is the function of CSF?
- Buoyancy - floats brain so that it doesn’t crush under its own weight
- Protection - protects brain from bumping into cranium during jolting movement
- -Concussion is a case of failed brain protection! - Chemical Stability - carries metabolic waste –> filters it through kidneys –> reabsorbed into blood plasma)
Where is CSF made?
CSF is made by Ependymal cells in the…
- -Choroid plexus (in each ventricle)
- -Subarachnoid space
Describe the the pathway of CSF
Lateral ventricles –> third ventricle –> fourth ventricle –> subarachnoid space –> dural sinus –> *circulatory system (heart + lungs) –> choroid plexuses (reabsorbs CSF as blood plasma)
What are the four fluid-filled chambers in the brain?
Ventricles - four chambers containing CSF
Lateral ventricles (2)
Third Ventricle
Fourth Ventricle
Regulates the entry of substances into the brain (blocks potentially harmful substances…toxins, pathogens, etc.)
Blood Brain Barrier (BBB)
Where is the Blood Brain Barrier missing + why?
BBB missing in…
- -Circumventricular organs (CVOs)
- -Third + Fourth ventricles - route for HIV invasion!
Why?
–These locations must monitor physiological conditions (glucose, pH, osmolarity, etc.)
What three brain parts are considered to be the brain stem?
- Midbrain
- Pons
- Medulla oblongata
Nuclei that extend up through the brainstem and into the midbrain
Recticular formation
What important physiological functions are controlled by the reticular formation?
- Somatic motor control - muscle tone, balance, posture, breathing, etc.
- Cardiovascular control
- Pain modulation - descending analgesic (painkiller) pathways block pain transmission
- Sleep/Consciousness - controls alertness
- -Reticular activating system - arouses + maintains consciousness - Habituation - learning to ignore repetitive stimuli
What is the corpora quadrigemina?
Tectum - contains the corpora quadrigemina (4 baby bodies)
- -Superior colliculi (2) - visual attention + “eye tracking”, involved in reflex response
- -Inferior colliculi (2) - receives signals from inner ear, involved in balance + hearing`
A region of gray matter on either side of the cerebral aqueduct in the midbrain.
Tegmentum
Dorsal part of the midbrain
Tectum
What are the parts of the Tegmentum?
- Red nucleus - fine motor control (along w/ cerebellum)
- Substantia nigra - sends inhibitory signals –> thalamus
- -Prevents unwanted body movements
- -Degeneration of this = muscle tremors
What are the three parts of the Diencephalon? What do they do?
- Thalamus “Gatekeeper” - filters stimuli + relays signals from cerebellum –> cerebrum
- -Involved in senses - Hypothalamus “Master Gland” - controls ANS and endocrine system
- -Involved in hormones, heart rate, BP, thermoregulation - Epithalamus (Pineal Gland) - controls diurnal rhythms
- -Involved in production of melatonin, and ultimately sleep
What does the Cerebellum control?
Complex movements (motor control, “muscle memory” etc.)
What are the consequences to injury of the Cerebellum?
- -Cerebellar lesions - deficit in coordination, locomotion, linguistics, emotions + non-motor functions like difficulty planning
- -Small cerebellums - related to ADHD in children
Worm-like structure that separates the cerebellum into two hemispheres
Vermis
What is the function of the Vermis?
Maintains equilibrium
What are the three nerve tracts of the brain?
- Projection fibers - connect inferior + superior regions of the brain
- Association tracts - connect parts of a lobe that communicate w/ one another (usually for the same purpose)
- Commissural tracts - connect L + R hemispheres, pass through the corpus callosum
Part of the cerebral cortex involved in high-order brain functions in mammals
Neocortex
What are the different roles played by Stellate and Pyramidal neurons?
- Stellate - SENSORY
- -Take in sensory info - Pyramidal - MOTOR (OUTPUT)
- -Respond to stimuli
In which cerebral lobe does motor function and personality reside?
Frontal
Which cerebral lobe provides sensory information about your skin and muscles?
Parietal
Which cerebral lobe receives and processes visual stimuli?
Occipital
In which cerebral lobe are auditory signals processed?
Temporal
What two cerebral locations are responsible for speech?
Cerebral Cortex:
- -Broca’s Area - motor-speech (Frontal lobe)
- -Wernicke’s Area - interprets speech (where Parietal + Temporal lobe meet)
What cerebral lobe is buried deep inside the transverse sulcus? What is its job?
Insula - understanding spoken language, taste, visceral sensation
What are the parts of the Limbic system?
- Cingulate gyrus - coordinates sensory info w/ emotions
- Mammillary bodies
- Fornix
- Hippocampus - organizes long-term memory (memory consolidation)
- -Dentate gyrus - place where new memories are established (new neurons –> new memories) - Amygdala - draw attention to novel stimuli
Place where new memories are established
Dentate gyrus of Hippocampus
What dire consequence for survival might occur if the Amygdala is damaged by a brain injury?
Inability to feel fear
- -Creates a safety hazard; unable to be cautious of dangerous situations
ex: crossing the street
Coma-like state in which we can be aroused by stimulation
Sleep
Sleep + comas are similar in ____ ____ activity.
brain wave
What are the stages of sleep?
1, 2, 3, 4, REM, 4, 3, 2, 1
Shallow: 1 - 3
Deep: 4
In what stage of sleep does dreaming occur + body muscles become paralyzed?
REM - Rapid Eye Movement
What are some side effect from a lack of sleep?
- -Increased risk of stroke, heart attack, and psychosis
- -Immune system depression –> death!
Type of brain waves during mental activity + sensory stimulation
Where are they located?
Beta
Frontal - Parietal
Type of brain waves during awake, but relaxed phases
Where are they located?
Alpha
Parietal - Occipital
Type of brain waves used during deep relaxation or meditation
What is this brain wave also associated with?
Theta
Also associated w/ emotional stress + brain disorders
Type of brain waves used during deep sleep in adults
Does dreaming take place in this state?
Delta
NOT associated w/ dreaming
What three cranial nerves are responsible for your sense of smell, vision, and hearing?
- Olfactory (I) - smell
- Optic (II) - vision
- Vestibulocochlear (VIII) - hearing
What three cranial nerves are responsible for eye movements?
- Oculomotor (III)
- Trochlear (IV)
- Abducens (VI)
Which cranial nerve is responsible for facial sensations?
Trigeminal (V)
Damage to which cranial nerve will result in the loss of facial muscle control and distorted tastes?
Facial (VII)
Which two cranial nerves are involved in the process of swallowing?
Glossopharyngeal (IX) + Vagus (X)
Which cranial nerve is primarily in control of the ANS?
Vagus (X)
Which cranial nerve controls shoulder movements?
Accessory (XI)
Which cranial nerve is responsible for tongue movements?
Hypoglossal (XII)
