Chapter 14 Part 2 Flashcards
what is the most inferior of the brain regions?
the medulla oblongata
ALL COMMUNICATION BETWEEN THE BRAIN AND SPINAL CORD involves tracts that ascend or descend through the….
medulla oblongata
true or false..
the medulla oblongata is a very busy place
TRUE
all communication between the brain and spinal cord passes in ascending or descending tracts through the medulla oblongata
the inferior portion of the medulla oblongata resembles….
the spinal cord – small central canal
as one ascend the medulla oblongata, the central canal opens into…
the 4th ventricle
the CSF circulates into the subarachnoid space through which structures?
2 lateral apertures and one median aperture
which matter contains ascending and descending tracts?
white matter (myelinated axons = faster)
name the functions of the medulla oblongata
-relays sensory info to the thalamus and other parts of the brain stem
-has AUTONOMIC CENTERS for the regulation of visceral function (cardiovascular, respiratory, and digestive system activities)
what links the cerebellum with the midbrain, diencephalon, cerebrum, and spinal cord?
the pons
name the functions of the pons
-relays sensory information to the cerebellum adn thalamus
-subconscious somatic and visceral motor centers
name the functions of the cerebellum
-coordinate COMPLEX somatic motor patterns
-adjust the output of other somatic motor centers in the brain and spinal cord
-HELPS MAINTAIN BALANCE AND EQUILIBRIUM
What are Purkinje cells?
cells in the cerebellar cortex.
they are huge and highly branched with extensive dendrites to form up to 200,000 synapses
what is ataxia?
what can cause it?
ataxia = a disturbance in muscular coordination
caused by permanent damage to the cerebellum by trauma or stroke. OR temporarily affected by drugs such as alcohol
in severe ataxia, person cannot sit or stand without assistance
what is the function of the midbrain?
-process visual and auditory data
-generate reflexive somatic motor responses
-maintain consciousness
the diencephalon consists of….
the epithalamus
thalamus
hypothalamus
the _____ is the roof of the diencephalon, superior to the 3rd ventricle
epithalamus
the posterior portion of the epithalamus contains the…
pineal gland
explain what the pineal gland is
an endocrine structure that secretes melatonin
most of the neural tissue of the diencephalon is concerned where?
the left and right thalamus
what forms the walls of the diencephalon?
what forms the floor of the diencephalon?
lateral walls = the left and right thalamus
floor = hypothalamus
ascending sensory information from the spinal cord or cranial nerves synapses in a nucleus ______(where) before reaching the cerebral cortex and our conscious awareness
in the left or right thalamus
what is the function of the thalamus
has relay and processing centers for sensory information
what is the function of the hypothalamus
has centers controlling emotions, autonomic functions, and hormone production
what is the “link” between the nervous and endocrine systems?
the hypothalamus
on each side of the diencephalon, the _______ is the final relay point for ascending sensory information that will be projected to the primary sensory cortex
thalamus
explain how the thalamus passes on the sensory info to the primary sensory cortex
the thalamus acts as a FILTER, passing on only a small portion of the arriving sensory information
besides passing on filtered sensory information to the primary cerebral cortex, what else does the thalamus do?
coordinates the activities of the basal nuclei and cerebral cortex by relaying information between them
what separates the left and right thalamus from each other?
the third ventricle
explain how the hypothalamus coordinates neural and endocrine activities
by inhibiting or stimulating endocrine cells in the pituitary gland through the production of REGULATORY HORMONES
Besides regulatory hormones to regulate the pituitary gland, what other 2 hormones does the hypothalamus secrete and what is their function?
ADH (antidiuretic hormone)
OXT (oxytocin)
ADH – restricts water loss by the kidneys
OXT – stimulates smooth muscle contractions in the uterus and mammary glands of females, and prostate glands of males
ADH is produced where and by which nucleus?
a nucleus in the hypothalamus called the SUPRAOPTIC NUCLEUS
Oxytocin is produced where and by what specific nucleus?
in the hypothalamus by PARAVENTRICULAR NUCLEUS
explain how the hypothalamus produces “emotions and behavioral drives”
the hypothalamus has a feeding center and a thirst center
feeding center produces the sensation of hunger
thirst center produces the sensation of thirst
these impressions originating in the hypothalamus are called “drives”
what else does the thirst center do, besides giving the sensation of thirst?
the thirst center also orders the release of ADH by supraoptic nucleus
explain how the hypothalamus coordinates between voluntary and autonomic functions
when you think of a scary event, your heart and respiratory rate go up and your body prepares for emergency.
these AUTONOMIC ADJUSTMENTS are made up by the hypothalamus (increased heart and respiratory rate )
what area of the hypothalamus helps to maintain body temp?
the preoptic area of the hypothalamus
if body temperature is too low, explain what will happen
the preoptic area in the hypothalamus will communicate with the vasomotor center (autonomic center in the medulla oblongata) and the vasomotor center will DECREASE BLOOD SUPPLY TO THE SKIN, reducing the rate of heat loss
what nucleus controls circadian rhythm?
suprachiasmatic nucleus
explain how the suprachiasmatic nucleus controls circadian rhythm
it receives input from the retina of the eye and its output adjusts the activities of other hypothalmic nuclei, the pineal gland, and reticular formation
the limbic system includes….
nuclei and tracts along the border between the cerebrum and diencephalon
name 3 functions of the limbic system
- establish emotional states
- linking conscious, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brain stem
- facilitating memory storage and retrieval
the limbic system is also known as the ___ system
explain
MOTIVATION
the cerebral cortex ENABLES you to perform complete tasks, but the LIMBIC SYSTEM MAKES YOU WANT TO DO THEM
What is the structure of the limbic system that appears to act as an interface (meeting place) between the limbic system, cerebrum, and various sensory systems?
the amygdaloid / amygdala
the amygdala plays a role in….
the regulation of heart rate, control of fight or flight response of the sympathetic division of the ANS, and in linking emotions with specific memories
the “limbic lobe” of the cerebral hemisphere consists of…..
the gyri (superficial folds in the brain) and underlying structures adjacent to the diencephalon
name the 3 gyri in the limbic lobe
-cingulate gyrus
-dentate gyrus
-parahippocampul gyrus
the 3 gyri in the limbic lobe conceal what structure? explain its function
the hippocampus – a nucleus that resembles a seahorse
function: important in learning, esp the storage and retrieval of new long-term memories
what is the name of the fiber tract that leads to the 2 cerebral hemispheres that the gyri of the limbic lobe curve along?
the corpus callosum
what is the fornix?
a tract of WHITE MATTER that connects the HIPPOCAMPUS with the HYPOTHALAMUS
What is the function of mamillary bodies and where are they located?
in the hypothalamus
function: control feeding reflexes
what is the function of the autonomic centers of the hypothalamus?
control medullary nuclei that regulate heart rate and blood pressure
what is the function of tuberal nuclei and where are they located?
in the hypothalamus
function: release hormones that control the endocrine cells of the pituitary gland
what is the function of the ANTERIOR NUCLEUS of the thalamus?
part of the limbic system
relays information from mamillary body to cingulate gyrus
what is the response of stimulation or inhibition of reticular formation in the limbic system?
affects emotions such as sexual arousal, rage, fear, or pain
within the cerebrum, where is gray matter located?
in the cerebral cortex, and in deeper basal nuclei
where is the white matter in the cerebrum?
deep to the cerebral cortex, around the basal nuceli
what is the function of the gyri?
to increase the surface area of the cerebral hemispheres
has the human brain expanded over time? explain
YES
the cerebral hemispheres have enlarged at a much faster rate than the rest of the brain.
this reflects the large # of neurons needed for complex analytical and integrative functions.
since the neurons are in the SUPERFICIAL layer of the cerebral cortex, it is there that expansion has been most pronounced.
therefore, the only option other than enlargement of the entire skull was for the cortical layer to fold like a crumpled piece of paper
the 2 cerebral hemispheres are almost completely separated by what structure?
a deep longitudinal fissure
is the pattern of our brain unique (the gyri and sulci?)
YES - like a fingerprint
do the 2 cerebral hemispheres have different functions?
yes – even though they look almost identical
normal individuals use which portion of the brain?
all portions
the motor areas of the left cerebral hemisphere control muscles on the ___ side
and vice versa
right
the interior of the cerebrum consists mostly of WHITE MATTER.
the axons can be classified as:
- Association fibers
- Commissural fibers
- Projection fibers
what are basal nuclei?
masses of gray matter that lie deep to the floor of the lateral ventricle.
they are embedded in the white matter of the cerebrum
the basal nuclei are part of a larger functional group called…
basal ganglia
the basal ganglia includes…
-the basal nuclei of the cerebrum
-associated motor nuclei in the diencephalon and midbrain
what is the function of the basal nuclei?
subconscious control of skeletal muscle tone and the coordination of learned movement patterns
activity of the basal nuclei is inhibited by….
neurons in the subtantia nigra in the midbrain which release the neurotransmitter DOPAMINE
If the substantia nigra is damaged or they release less dopamine, what happens?
the basal nuclei become more active.
this results in increased muscle tone and the appearance of symptoms characteristic of PARKINSONS DISEASE
explain parkinsons disease
people have trouble starting voluntary movements because opposing muscle groups do not relax: they must be overpowered by intense effort and concentration
what does the term “hemispheric lateralization” mean?
functional differences between left and right hemispheres.
each cerebral hemisphere performs certain functions that are not ordinarily performed by the opposite hemisphere
reading, writing, and speaking are done dependent on which hemisphere?
the left
the premotor cortex involved with the control of hand movements is larger on the ____ side for right handed individuals, and larger on the __ side for left handed individuals?
larger on the left side for right handed
larger on the right side for left handed
besides reading, writing, and speaking, what else is an important function of the left hemisphere?
analytical thinking such as mathematical calculations and logical decision making
THIS IS WHY THE LEFT HEMISPHERE IS KNOWN AS THE DOMINANT HEMISPHERE
What are the functions of the RIGHT hemisphere?
analyze sensory information and relate the body to the sensory environment.
permit us to identify objects by our senses.
ex: recognizing faces, emotional context of a conversation
people with a damaged right hemisphere may be unable to….
add emotional inflection to their words
left handed people represent __% of the population
9
we have a primary __ and ___ cortex
primary motor cortex and primary sensory cortex
