Gross Anatomy of Brain & Spinal Cord Flashcards
what is the brain enclosed by?
the bony NEUROCRANIUM
how can skeletal muscle control by the brain be described?
CONTRALATERAL CONTROL
- left side of brain controls right side of brain
do both cerebral hemispheres contribute the same amount of use as each other?
No
- one cerebral hemisphere (left in 90%) is usually the dominant hemisphere
what is the dominant hemisphere of the brain responsible for?
complex functions such as:
- language
- reading
- speech
- writing
what is the non-dominant cerebral hemisphere responsible for?
- orientation of body in relation to surroundings
- visual experiences
- interpreting music patterns
- thought processes involving emotions and intuition
what are the two cerebral hemispheres connected by?
corpus callosum
what are the elevations located on the cerebral hemisphere known as?
GYRI
what are the infoldings on the cerebral hemispheres known as?
SULCI
what is the function of GYRI and SULCI?
increase surface are of brain
what type of matter lies on the outer aspect of the brain?
Gray matter on outside (white on inside)
what divides the cerebrum into the left & right hemispheres?
the longitudinal fissure
how are lobes of the brain named?
named by the overlying bone (except insula)
why is the INSULA interesting?
No overlying bone
- deep to three of the other lobes so does not correspond to a named overlying bone
what is the cerebrum responsible for?
higher brain activities such as:
- memory, intelligence & personality
- interpretation of impulses from sense organs & initiation of voluntary muscle movement
what is the vermis?
unites the two lateral hemispheres of the cerebellum
what are the ridges of the cerebellum called?
Folia
how can the cerebellums control of balance be described?
IPSILATERAL control
what can the brainstem be divided into?
- midbrain
- pons
- medulla oblongata
what cranial nerves are associated with the midbrain?
CNIII (occulomotor) & CNIV (trochlear)
what cranial nerve in the pons associated with?
CNV (trigeminal)
what cranial nerves are associated with the medulla oblongata?
CNIX (glossopharyngeal), CNX (vagus) & CNXII (hypoglossal)
what cranial nerves emerge at the junction between the pons and the medulla?
CNVI (abducens), CNVII (facial), CNVIII (vestibuloccular)
what is the diencephalon?
the central core of the brain?
what is the diencephalon composed of?
- epithalamus
- thalamus
- hypothalamus
what is the largest lobe of the cerebral cortex?
the frontal lobe
what can be found in the frontal lobe?
- profrontal cortex
- motor cortex
- broca’s area
where is the prefrontal cortex found?
anterior to the pre-central gyrus
what is the prefrontal cortex involved in?
- personality
- depth of feeling
- problem solving
- complex planning
- decision made
what is the function of the frontal lobe?
planning, control & execution of following movements
what is the function of Broca’s area?
- regulation of breathing patterns while speaking and vocalisations required for normal speech
where is Broca’s area usually found?
left hemisphere
what occurs if a patient has Broca’s Aphasia?
sounds made but words not formed
what is the function of the parietal lobe?
processing of sensory information
what are the two divisions of the parietal lobe?
- primary somatosensory cortex (S1)
- posterior parietal cortex
where is the primary somatosensory cortex located?
Parietal lobe
- located in the post central gyrus (just behind the central sulcus)
what is the function of the primary somatosensory cortex?
tactile sensation & responsible for:
- conscious perception of pain, pressure, taste, temperature, touch & vibration
what is the function of the posterior parietal cortex?
Integration of sensory information to allow:
- spatial perception
- spatial attention
- cognitive function
what is the function of the occipital lobe?
visual processing centre of the brain
what is located in the occipital lobe?
Primary visual cortex
what is the function of the primary visual cortex & where is it found?
- located around the calcarine sulcus
- receives visual information from the thalamus (allows for conscious perception of visual cortex)
what is the main function of the temporal lobe?
processes sensory information
- very important for language & language learning
What is located within the temporal lobe?
- auditory cortex
- Wernickles area
what is the function of Wernicke’s area?
language comprehension
what are the affects of Wernicke’s aphasia?
person is unable to comprehend written & spoken language
- hard to communicate as can’t understand words
- able to speak words fine
what other roles does the temporal lobe have?
- long term memory formation (memory related to grammar & vocab)
- visual perception and recognition
- processing of olfactory stimuli
what is the Insula?
“fifth lobe” located deep to the lateral sulcus
- concealed by portions of frontal, temporal & parietal loves
what is the function of the anterior insula?
language
what is the function of the posterior insula?
involved in integrating information relating to touch, vision & hearing
what are the subdivisions of the corpus callosum?
- genu (anteriorly)
- splenium (posteriorly)
- body
- rostrum (inferiorly)
what area of the brain provides a horizontal pathway for myelinated axons?
Corpus Callosum
what is the corona radiata?
white matter fibres within the brain run to & from the cortex
what makes up the lentiform nucleus?
- caudate nucleus
- putamen
- globus pallidus
what is interthalamic adhesion?
when thalami are connect across & around the ventricle
what does the internal capsule contain?
- contains fibres running from thalamus to cortex
- and fibres running from cortex to thalamus, brainstem and spinal cord
why is a stroke in the internal capsule so serious?
stroke here has devastating effects on the CONTRALATERAL side of the body as it is the site where motor fibres & pathways pass through
what blood vessels supply the internal capsule?
lenticulostriate arteries (small arteries that come from the middle meningeal artery)
where are the basal nuclei located?
located deep between the corona radiata and the brainstem
what are the basal nuclei & what is their function?
a group of subcortical nuclei involved in:
- motor control (main)
- also connected to limbic system pathways which are responsible for expression of various behaviours & motivational states
what are the 5 basal nuclei?
- caudate nucleus
- putamen
- globus pallidus
- subthalmic nucleus
- substantia nigra
where is the subthalmic nucleus (basal nuclei) located?
DIENCEPHALON
where is the substantia nigra (one of the basal nuclei) located?
MIDBRAIN
what is the function of the thalamus?
acts as a relay to convey information to the cerebral cortex
why are the basal nuclei important?
they mediate the beginning, ending & monitor the intensity of movements from the cortex
- filter out any responses that are inappropriate/incorrect
if the basal nuclei are to be damaged, what may occur?
- loss of control of smooth movements
- loss of ability to inhibit unnecessary or antagonistic movements
what are examples of diseased in which the basal nuclei are damaged or affected?
- parkinson’s disease (difficulty in initiating movements)
- huntington’s disease (over activation leads to excessive & jerky movements)
where is the hypothalamus located in relation to the thalamus? what is it connected to?
sits inferior & anterior to the thalamus
- connected to the pituitary gland via the pituitary stalk
what is the function of the hypothalamus?
Maintaining homeostasis by monitoring internal environment & controlling autonomic systems
- consumption of fluid & food
- temperature control
- sleep/wake cycle
- growth & reproduction
what gland does the hypothalamus control?
controls release of hormones from the pituitary gland (via releasing hormones)
what hormones are released from the pituitary gland?
- growth hormone
- thyroid stimulating hormone
- follicle stimulating hormone
- adrenocorticotrophic hormone
- lutenizing hormone
- prolactin
what is the condition that involves excessive growth of bones?
Acromegaly
what is the cause of Acromegaly?
over production of growth hormone by the pituitary gland
- normally caused by pituitary tumour
what are the symptoms of Acromegaly?
- growth of hands & feet
- large lips, nose & tongue
- deep voice
- increased jaw size & teeth spacing
if Acromegaly is left untreated what may occur?
- high blood pressure
- diabetes
- sleep apnoea
what are ventricles?
fluid fulled cavities within the brain that provide protection to the brain
- produce & circulate CEREBROSPINAL FLUID
what is the cerebrospinal fluid produced by in the ventricles?
chordial epithelial cells of choroid plexus (located in each ventricle)
what separates the lateral ventricles?
septum pellucidum
what is the function of cerebrospinal fluid?
provides buoyancy that prevents weight of brain from compressing cranial nerve roots & blood vessels against the internal surface
what can the brian stem be split into?
- midbrain
- pons
- medulla oblongata
what are the main functions of the brainstem?
- conduit or tracts ascending & descending through the CNS
- houses cranial nerve nuclei (CNIII-CNXII… but not CNXI)
- location of reflex centres related to respiration, cardiovascular function & regulation of consciousness
what are the boundaries of the spinal cord?
- begins are foramen magnum of skull as continuation of medulla
- ends at L1/L2 vertebrae in adults
what is the inferior end of the spinal cord known as?
conus medullaris
- continues as the film terminale
what is the function of the filum terminale?
continuous with pia mater superiorly & anchors the spinal cord to the coccyx inferiorly
what type of fibres are located in the anterior horns of the spinal cord?
efferent motor
what type of fibres are located in the posterior horns of the spinal cord?
- afferent sensory
what do ventral & dorsal roots converge to become?
a spinal nerve (composed of motor & sensory fibres)
where does spinal nerve C1 emerge from?
between the occipital bone of the skull & C1/atlas
where do all spinal nerves emerge? how are they numbered?
between adjacent vertebrae (apart from spinal nerve C1)
- numbered according to the vertebra below them (C8 is the exception)
what is a myotome?
anatomically & functionally related group of skeletal muscle
what is a dermatome?
localised area of skin
what is interesting about spinal nerve C1 (in relation to myotomes & dermatomes)?
- has no dermatome
lacks significant afferent component & does not supply the skin
