Bio Lecture 10 Flashcards
_______ – largest and most superior part of the brain, divided into two hemispheres separated by a longitudinal fissure
Cerebrum
_______ – second largest part of the brain, inferior to the cerebrum
Cerebellum
_________– all of the brain except the cerebrum and cerebellum
Major components include the medulla oblongata, pons, midbrain, and diencephalon
Brainstem
_______ matter lacks myelin and forms a surface layer called a cortex over the cerebrum and cerebellum
Grey
_______ matter forms deeper masses called nuclei surrounded by white matter
Grey
_______ matter contains myelin and lies deep to the cortical gray matter in most of the brain
(opposite the pattern of grey and white matter in the spinal cord)
White
___ ______ – different from the dura mater in the spinal cord in that there are two layers of dura mater
Dura mater in meninges
The ________ layer adheres to the inside of the cranium
periosteal
The ________ layer lies within and continues into the vertebral canal
There is no epidural space in the cranium
meningeal
______ – transparent membrane over the brain surface between the dura mater and pia mater
Arachnoid
___ _____ – thin delicate membrane that closely follows all the contours of the brain surface, even dipping into the grooves (sulci)
Pia mater
The brain has 4 fluid-filled chambers
There are two_____ ______, each of which forms an arc in a cerebral hemisphere
There is a third ventricle near the _____ of the cerebrum
There is a fourth ventricle _____ to the cerebellum
lateral ventricles
center
anterior
On the floor or wall of each ventricle there is a ______ ______
choroid plexus
The choroid plexus is a ______ ____ of blood capillaries
spongy mass
The choroids plexus produces some _________ fluid; the rest of the fluid comes from the lining of the ventricles or from the subarachnoid space
cerebrospinal
_______ _____ is a clear, colorless liquid that fills the ventricles and canals of the CNS and bathes its external surface
It is formed by filtration of blood plasma
Cerebrospinal fluid
_______ ___ chemically modify the filtrate as it passes through them into the ventricles and subarachnoid space
Ependymal cells
_______ – because the brain and CSF are similar in density, the brain neither sinks nor floats
Buoyancy
_______– CSF protects the brain from striking the cranium when the head is jolted
Protection
_______ _______ – the flow of CSF rinses metabolic wastes from nervous tissue and regulates its chemical environment
Chemical stability
______ is a source of bacterial toxins and other agents that can harm brain tissue
Blood
The _____-____ barrier strictly regulates which substances get from the bloodstream into the tissue fluid of the brain
blood-brain
Anything passing from the blood into the tissue fluid has to pass through the ________ ____ themselves, which are more selective than gaps between cells
endothelial cells
________ ________ -The most caudal part of the brainstem, immediately superior to the foramen magnum of the skull
medulla oblongata
medulla oblongata:
It connects the spinal cord to the rest of the brain
It regulates the rate and force of the heartbeat
It regulates blood pressure and flow
It regulates the rate and depth of breathing
____ - The section of the brainstem between the midbrain and medulla oblongata
pons
______ is the source of most nerve fibers carrying signals from the brainstem to the cerebellum
pons
Nerves from the ____ control eye movements, facial expression, chewing, and swallowing, and they receive sensory signals including taste, hearing, equilibrium, touch, and pain
pons
The _______ - Large portion of the brain dorsal to the brainstem and inferior to the cerebrum
Cerebellum
Two hemispheres are connected by a narrow bridge called the ______
vermis
In sagittal section, the inner white matter, called the _____ ______, looks like a branching fern
arbor vitae
The cerebellum: (5)
smooths muscle contractions
maintains muscle tone and posture
coordinates the motions of different joints with each other
coordinates eye and body movement
serves in learning and storing motor skills
The _________ - Short section of the brainstem that connects the hindbrain and forebrain
midbrain
The midbrain contains the _______ ___________ (2 superior and 2 inferior colliculi)
corpora quadrigemina
_______ ________ – functions in visual attention, such as turning the eyes and head in response to a visual stimulus
Superior colliculi
_______ ________ – receives and processes auditory input from lower levels of the brainstem and relays it to other parts of the brain
Inferior colliculi
the _______ ____ -Center that improves motor performance by suppressing unwanted muscle contractions
substantia nigra
(in midbrain)
The _______ _______ - Loosely organized web of gray matter that runs vertically through all levels of brainstem and to many areas of the cerebrum
The reticular formation
Plays roles in somatic muscle control, cardiovascular control, pain modulation, consciousness, and habituation
The reticular formation
The __________– includes thalamus, hypothalamus, and epithalamus
diencephalon
_______– oval mass of gray matter underlying each cerebral hemisphere
Gateway to the cerebral cortex – signals going to and from the cerebrum pass through this region
Thalamus
_________– sits below the thalamus and connects to the pituitary gland
Hypothalamus
The Hypothalamus is involved in: (7)
hormone secretion
autonomic effects
thermoregulation
food and water intake
sleep and circadian rhythms
emotional responses
memory
_______ – consists mostly of the pineal gland, which produces melatonin which helps regulate our sleep-wake cycle
Epithalamus
The _______ – largest and most superior portion of the brain
Is marked by gyri (thick folds) and sulci (depressed grooves)
Cerebrum
The two hemispheres are separated by a _______ fissure
At the bottom of this fissure, the hemispheres are connected by a thick “C” shaped bundle of nerve fibers called the corpus callosum
longitudinal
______ lobe – behind frontal bone, concerned with cognition, speech, and motor control
Frontal
______ lobe – under parietal bones, concerned with receiving and interpreting general senses as well as taste
Parietal
_______ lobe – at the rear of the head, concerned with vision
Occipital
_______ lobe – lateral and horizontal lobe, concerned with hearing, smell, learning, memory, and some aspects of vision and emotion
Temporal
_____– deep lobe (normally covered), plays some roles in taste, hearing, and visceral sensation
Insula
cant see from outside
Which Nerve?
Composition: Sensory
Function: Smell
Origin: Olfactory mucosa in nasal cavity
Termination: olfactory bulb
Cranial passage: Cribiform plate of the ethmoid bone
Olfactory
Which Nerve?
Composition: Sensory
Function: Vision
Origin: Retina
Termination: thalamus
Cranial passage: Optic foramen
Optic
Which Nerve?
Composition: Motor with some proprioceptor fibers
Function: Eye movement, opening of eyelid, constriction of pupil, focusing
Origin: Midbrain
Termination: superior, medial, and inferior rectus; and inferior oblique eye muscles, constrictor of iris and ciliary muscles of lens
Cranial passage: superior orbital fissure
Oculomotor
Which Nerve?
Composition: Motor with some proprioceptor fibers
Function: Eye movements
Origin: Midbrain
Termination: Superior oblique eye muscle
Cranial passage: Superior orbital fissure
Trochlear
Which Nerve?
Composition: Sensory
Function: touch, temperature, and pain sensation in upper face
Origin: superior region of face
Termination: pons
Cranial passage: superior orbital fissure
Opthalmic division
of Trigeminal
Which Nerve?
Composition: sensory
Function: touch, temperature, and pain sensation in lower face
Origin: middle region of face
Termination: pons
Cranial passage: foramen rotundum
Maxillary division
of Trigeminal
Which Nerve?
Composition: sensory and motor
Function: touch, temperature, and pain sensation in lower jaw, mastication
Sensory Origin: inferior region of face
Sensory Termination: pons
Motor Origin: Pons
Motor Termination: muscles of mastication
Cranial passage: Foramen ovale
Mandibular division
of Trigeminal
Which Nerve?
Composition: Motor with some proprioceptor fibers
Function: eye movements
Origin: inferior pons
Termination: lateral rectus
Cranial passage: superior orbital fissure
Abducens
Which Nerve?
Composition: Mixed
Function: motor nerve of facial expression, control of salivary glands, sensation of taste on anterior two-thirds of tongue
Sensory Origin: Taste buds on anterior two-thirds of tongue
Sensory Termination: thalamus
Motor Origin: pons
Motor Termination: muscle of facial expression, salivary glands
Cranial passage: mastoid foramen
Facial
Which Nerve?
Composition: sensory
Function: hearing and equilibrium
Origin: inner ear
Termination: pons
and medulla oblongata
Cranial passage: internal auditory meatus
Vestibulocochlear
Which Nerve?
Composition: mixed
Function: swallowing, regulation of blood pressure and respiration, taste sensations on the posterior one-third of the tongue
Sensory Origin: Pharynx, posterior one-third of tongue, internal carotid arteries
Sensory Termination: medulla oblongata
Motor Origin: Medulla oblongata
Motor Termination: salivary glands, muscles of swallowing
Cranial passage: jugular foramen
Glossopharyngeal
Which Nerve?
Composition: Mixed
Function: cardiovascular and gastrointestinal regulation; sensations of hunger, fullness, and intestinal discomfort
Sensory Origin: thoracic and abdominal viscera
Sensory Termination: medulla oblongata
Motor Origin: medulla oblongata
Motor Termination: thoracic and abdominal viscera
Cranial passage: jugular foramen
Vagus
Which Nerve?
Composition: Motor with some proprioceptive fibers
Function: swallowing; head, neck, and shoulder movements
Origin: medulla oblongata and segments of C1-C5
Termination: Palate, pharynx, sternocleidomastoid and trapezius
Cranial passage: jugular foramen
Accessory
Which Nerve?
Composition: Motor with some proprioceptive fibers
Function: food manipulation, swallowing, speech
Origin: medulla oblongata
Termination: muscles of the tongue
Cranial passage: hypoglossal canal
Hypoglossal
