anatomy lab 3

what are the four major portions the brain can be divided into?

cerebrum, diencephalon, brain stem, and cerebellum

what is the cerebrum responsible for?

conscious thought process

what is the diencephalon responsible for?

relaying sensory and motor signals to the cerebral cortex and regulates sleep-wake cycle, body temperature, and appetite

what is the function of the brain stem?

make connections between the higher portions of the brain, the spinal cord, and the cerebellum and regulate breathing, heart rate, and blood pressure, and plays a crucial role in reflexes, sleep-wake cycles, and sensory/motor functions of the head and face

what is the function of the cerebellum?

coordination of movements and balance

what are the membranes that wrap the brain and spinal cord called?

meninges

what are cranial meninges?

three distinct layers of connective tissue that support and protect the soft tissue of the brain

what is the first layer of meninx found on the brain/spinal cord?

pia mater

what is pia mater?

a very thin and nearly transparent layer of areolar connective tissue that directly covers the surface of the brain

what is the layer after pia mater? why is it named that?

arachnoid mater; it has a web-like appearance

what is found between the pia mater and arachnoid mater? what is it filled with?

subarachnoid space; filled with cerebrospinal fluid (CSF)

what is the function of cerebrospinal fluid?

support and protect the brain, and also deliver nutrients to and remove waste from the brain

what is the outermost meninx called? what is it made up of?

dura mater; two layers of dense irregular connective tissue

what are the two layers of tissue found in the dura mater called?

there is a inner meningeal layer and an outer periosteal layer

what is the meningeal layer in contact with?

arachnoid mater

what does the periosteal layer do?

lines the inside of the cranium

what is the position of the cerebellum relative to the brain stem?

the cerebellum is posterior to the brain stem

briefly describe some problems a person might have if a stroke damaged his cerebellum.

the person would have issues with balance, movement, and coordination

between which of the cranial meninges is cerebrospinal fluid found?

pia and arachnoid mater, CSF is found in subarachnoid space

what is the layer of gray matter found on the surface of the cerebrum called?

cerebral cortex

what is found in the gray matter of the brain?

neuron bodies and unmyelinated axons

what do the neuron bodies in the cerebral cortex (gray matter of brain) help do?

form the conscious mind

what are the elevated parts of the cerebrum called?

gyri

what are the depressed parts of the cerebrum called?

sulci

what do the gyri and sulci help do?

increase the surface area of the cerebral cortex and room for billions of neurons

what is the cerebrum divided into? what are they called?

left and right halves called cerebral hemispheres

what divides the two hemispheres?

a deep midsagittal groove called the longitudinal fissure

what are the four lobes that make up the cortex of both hemispheres?

frontal, parietal, temporal, occipital

what is the function of the frontal lobe?

personality, movement, back and forth eye movement, emotion, judgement, thinking

where is the precentral gyrus located? what is its function?

in the frontal lobe; responsible for directing somatic motor commands

what separates the frontal and parietal lobe?

central sulcus

what are the functions of the parietal lobe?

conscious processing of somatosensory information (ex. touch and body position) and language

where is somatosensory information processed?

in the postcentral gyrus located in the parietal lobe

what separates the parietal and temporal lobe?

lateral sulcus

what are the functions of the temporal lobe?

processing auditory and olfactory sensations

what is the function of the occipital lobe?

processing visual information

what is the location of the insula? what is the function of the insula?

deep to the lateral sulcus; perception of taste, smell, digestion, visceral sensations (e.g., pain, hunger, thirst)

what make up the cerebral white matter?

myelinated axons

what is the function of the myelinated axons of the cerebral function?

they connect the billions of cortical neurons to each other and to lower portions of the CNS

what type of matter is found in the corpus callosum? what is its function?

white matter; its axons connect the two cerebral hemispheres to each other

what is the function of the fornix?

connects portions of the cerebrum and diencephalon

what thin membrane is between the corpus callosum and fornix? what is its function?

septum pellucidum; separates the two lateral ventricles

what are ventricles?

cavities in the brain that contain CSF

what visible structure seperates the frontal lobe from the parietal lobe?

central sulcus

what are the two main portions of the diencephalon?

thalamus and hypothalamus

what is the function of the thalamus?

collects various conscious senses (except smell), filters information, and directs important information to the appropriate area of the cerebral cortex

when you’re having a conversation in a crowded room, what does the thalamus do?

help process only important auditory information to the primary auditory cortex of the temporal lobe, allowing a person to focus on the conversation and not the background noise

what is the role of the hypothalamus?

the oversight of homeostasis within the body, relaying and filtering station for incoming olfactory information

what are the two small lumps that project from the underside of the hypothalamus?

mammillary bodies

function of mammillary bodies

memory and olfactory sensation

what is the thin stalk structure that the pituitary gland attaches to?

infundibulum

what is the role of the pituitary gland?

homeostasis of the body

what are the hormones released by the pituitary gland?

growth hormone, follicle-stimulating hormone, and thyroid-stimulating hormone

what is the space between the right and left sides of the diencephalon?

third ventricle

where is the choroid plexus located? what are their function?

superior to the third ventricle, inferior to the fornix; produces cerebrospinal fluid

name at least five specific functions of the hypothalamus

regulating body temperature, thirst, hunger, release of hormones, sleep-wake cycles, and maintaining homeostasis

what is the third ventricle associated with?

the diencephalon

what are the first and second ventricles and where are they?

they are the lateral ventricles; they can be found between the corpus callosum and fornix

what is the tectum? what is its function?

region of the midbrain made up of superior and inferior colliculus; associated with vision, hearing, motor control, sleep and wakefulness

function of brain stem

form pathways between various structures such as cerebellum, diencephalon, and cerebrum

what is the superior part of the brain stem? what is it composed of?

midbrain; myelinated axons

what do the four lumps on the tectum of the midbrain make?

the corpora quadrigemina

what can the corpora quadrigemina be split into?

superior colliculi and inferior colliculi

what is the superior colliculi for?

vision and visual reflexes

function of visual reflexes within superior colliculi

move your head and eyes to view moving objects

what is the inferior colliculi for?

hearing and auditory reflexes

function of auditory reflexes of the inferior colliculi

move your head in response to startling sounds

what is the arbor vitae and its functions?

the tree-like white matter tracts in the cerebellum that provide afferent and efferent (incoming and outgoing) sensory and motor information to and from the cerebellum

what does arbor vitae mean?

“tree of life”

what are the neuron bodies in the pons called and what are their function?

nuclei, they are involved in maintaining the rhythm of breathing

what do the descending tracts of axons running through ventral portions of the medulla do?

carry commands from the brain to motor neurons in the spinal cord

what do the ascending tracts of axons running through dorsal portions of the medulla do?

carry sensory information from the spinal cord to the brain

what do the nuclei in the medulla do?

exert control over the heartbeat

what structure connects to both the third and fourth ventricle?

cerebral aqueduct

function of cerebral aqueduct

pathway for the flow of cerebrospinal fluid (CSF) throughout the brain and spinal cord

what are the four ventricles connected to? what flows through these spaces?

themselves, the central canal of the spinal cord, and the subarachnoid space that surrounds the brain and spinal cord; cerebrospinal fluid

a blow to the back of the head that damages the medulla oblongata may be fatal. why?

can obstruct and even cease regulation of breathing and heart rate, causing death

what separates the cerebrum and cerebellum?

the transverse fissure

what is the midsection of the cerebellum?

the vermis

what are the lateral sides of the cerebellum called?

cerebellar hemispheres

what are the folds in each cerebellar hemisphere of the cerebellum called? what are they seperated by?

folia; shallow sulci

what is a nerve?

a bundle of axons located outside of the CNS

how many pairs of nerves are attached directly to the brain and what are they called collectively?

12 pairs, cranial nerves

function of cranial nerves

carry information directly to and from the brain

what is another name for neurons that carry both sensory and motor information?

mixed nerves

what do cranial nerves attach to? what is the exception?

the brain stem; excluding the olfactory and optic nerves

cranial nerve I (name, type of nerve, major functions)

olfactory nerve, sensory, sense of smell

cranial nerve II (name, type of nerve, major functions)

optic nerve, sensory, sense of vision

cranial nerve III (name, type of nerve, major functions)

oculomotor nerve, motor, movement of eye

cranial nerve IV (name, type of nerve, major functions)

trochlear nerve, motor, movement of eye

cranial nerve V (name, type of nerve, major functions)

trigeminal nerve, mixed, sense of touch, pain, temperature, and proprioception; movement of chewing and middle ear muscles

cranial nerve VI (name, type of nerve, major functions)

abducens nerve, motor, movement of eye laterally

cranial nerve VII (name, type of nerve, major functions)

facial nerve, mixed, sensory impulse for taste, touch, pain, temperature, and proprioception, muscles of facial expression and middle; autonomic motor impulse for lacrimal (tears) and salivary (saliva) glands

cranial nerve VIII (name, type of nerve, major functions)

vestibulocochlear nerve, sensory, sense of hearing and balance

cranial nerve IX (name, type of nerve, major functions)

glossopharyngeal nerve, mixed, sensory impulse for taste, touch, pain, temperature, proprioception, swallowing; autonomic motor impulse to parotid gland (saliva)

cranial nerve X (name, type of nerve, major functions)

vagus nerve, mixed, sensory impulse for taste, touch, pain, temperature, proprioception, hunger, fullness, discomfort, speech, swallowing coughing; autonomic motor impulse for motility (movement of food through digestive tract), secretion, and decrease heart rate

cranial nerve XI (name, type of nerve, major functions)

accessory nerve, motor, movement of head

cranial nerve XII (name, type of nerve, major functions)

hypoglossal nerve, motor, movement of tongue

what problem would a person have if his oculomotor nerves were damaged? what if his optic nerves were damaged?

difficulty moving eyes; vision loss or blindness

what pair of cranial nerves also innervates various structures in the ventral body cavity? to what parts of the body is this nerve connecting the brain?

the vagus nerve (cranial nerve X); heart, lungs, stomach, and other organs in the chest and abdomen