24: The Brain Flashcards
Brain Stem
The Mesencephalon, the poins, and the medulla oblongata
Six parts of the brain
the cerebrum, the cerebellum, the diencephalon, the mesencephalon, the pons and the medulla oblongata
cerebrum
makes up about two-thirds of the brain. It is divided into left and right cerebral hemispheres
longitudinal fissure
Seperates the left and right cerebral hemispheres
Four Lobes
frontal lobe, parietal lobe, occipital lobe, and temporal lobe
central sulcus
separates the frontal lobe from the parietal lobes
lateral sulcus
separates the frontal and parietal lobes from the temporal lobes
cerebral cortex
outer five millimeters or so thickness of the cerebrum is composed of dense layers of nerve cell bodies and appears as gray matter
gyrus
Each surface convolution formed In order to accommodate the large number of neurons, the surface is thrown into folds are these
sulcus
The depression or fold between gyri
sensory, motor, and association areas
Located in the Cortex
precentral gyrus
(the cortex region just anterior to the central sulcus) is a somatic motor area
post central gyrus
(the cortex area just posterior to the central sulcus) is a somatic sensory area. Direct stimulation of this part of the cortex would be perceived by the subject as something touching a certain part of their body
temporal lobe
associated with hearing
occipital lobe cortex
associated with vision
left hemisphere
For most of us, this hemisphere is the categorical or “dominant” hemisphere, Language and all language-based abilities including science, math and logic, are seated in the categorical hemisphere
motor speech area (Broca’s area)
found in the frontal lobe of the categorical hemisphere enables us to communicate in words,
representational hemisphere
opposite hemisphere (right for most of us, It is the seat of imagination, music, art, perception of patterns, spatial relationships, and comparisons of smells, tastes, sights, and sounds
association areas
Besides sensory and motor areas, all lobes of the cortex also contain these
general interpretive area (Wernicke’s area)
developed in the categorical (usually left) hemisphere and is considered to be the seat of intelligence.
corpus callosum
Allows The cortex of the right hemisphere to communicate with the cortex of the left hemisphere via its myelinated fibers, (located at the bottom of the longitudinal fissure)
basal ganglia
regions of gray matter deep within the cerebrum
amygdala
A region in the temporal lobes, serves as the center of the limbic system,
cerebellum.
(Located below the occipital lobe and behind the brain stem is the second largest portion of the brain) coordinates muscle movements, making them occur in a smooth and fluid way
diencephalon
is located at the top of the brain stem and is surrounded by the cerebrum,Its two main parts are the thalamus and the hypothalamus
thalamus
serves as a relay center for higher areas of the brain. It is a crude sensory area
hypothalamus
is a link between the nervous system that communicates with electrical impulses and the endocrine system that communicates with hormones, produces ADH & Oxytocin
antidiuretic hormone (ADH)
produced by hypothalamus, that acts on the kidney to retain water
oxytocin
produced by hypothalamus,stimulates uterine contractions
hypothalamus controls
a thirst center, a center controlling appetite, one regulating body temperature, and an area controlling sexual cycles, to name a few, alos contains reward and punishment regions
mesencephalon
(midbrain) extending down from the diencephalon
reticular formation
also called the reticular activating system, acts to control the flow of information passing through the brain stem. When the reticular formation is active, we’re awake., filters out extra sensory input
Types of sleep
slow-wave and REM (rapid eye movement) sleep
human brain abilities
acquiring new information (learning), storing and retrieving information (memory) and eliminating trivial or unused information (forgetting)
anterograde amnesia
Brain injured persons unable to store new information
retrograde amnesia
Brain injured persons unable to retrieve existing information
declarative memory
the ability to recall past events
skill (procedural) memory
the ability to tie your shoes, for example
hippocampus
(in the temporal lobes) is an important learning center
Short-term memory
lasts for seconds and enables us to remember what just happened
Intermediate long-term memory
can last for minutes (looking for lost car keys) or hours (“cramming” for an exam).
Long-term memory
enables large amounts of information to be stored up to a lifetime
cerebral spinal fluid (CSF)
Cavities within the brain contain capillary tufts that produce this filtrate of blood closely resembling plasma
meninges
Surrounding the brain and spinal cord are three layers of connective tissue membranes
(dura mater and arachnoid mater
The outer two layers form a sort of loose sack around the brain and spinal cord
pia mater
A third layer, fits tightly over the surface of the brain and spinal cord
subarachnoid space
The space thus formed between the arachnoid mater and pia mater,
hydrocephalus
Since the skull cannot expand, any accumulation of CSF would increase intracranial pressure (that is normally about 10 mm Hg) and squeeze brain capillaries leading to permanent brain damage
cranial nerves
twelve pairs, emerge from the diencepahlon and brain stem. They are involved with motor and sensory function associated with the head and neck
