Brain Flashcards
What are the Bones of JUST THE SKULL
Frontal
Parietal
Occipital
Temporal
(see pics)
What are the bones of the face
Zygomatic- cheek bones
Mandible- lower jaw
*from outwards to inwards* Nasal Maxilla- upper jaw Lacrimal bone- medial wall of the orbit Ethmoid Sphenoid Temporal bone
what are the 3 main parts of the brain and what are their general functions
Cerebrum- the main bulk. Involved in sensory perception, cognition, spatial reasoning and language
Brainstem- has 3 parts (midbrain, pons and medulla oblongata). connects the brain to spinal cord. Breathing and Heart rate
Cerebellum- posteroinferior part of the brain. involved in balance, co-ordination and voluntary motor controls
What does the cerebrum consist of
cerebral cortex (lobes- frontal, parietal, occipital and temporal) subcortical strcuture: - hippocampus - basal ganglia - olfactory bulb
How is the cerebrum divided?
Composed of two hemispheres (R and L)
Hemispheres are separated by a longitudinal fissure
what is the cerebral cortex
the outer layer of grey matter of the cerebrum, the surface of which folds to create gyri (folds) and
sulci (grooves).
what is the purpose of the central sulcus
separates frontal lobe from parietal and temporal lobe
what is another purpose of the central sulcus
separates primary motor cortex from the primary somatosensory cortex
what is the purpose of the lateral sulcus
separates temporal lobe from other lobes of the brain
what are the names and functions of the gyrus anterior and posterior to the central sulcus
anterior to the central sulcus- precentral sulcus (motor)
posterior to the central sulcus- postcentral sulcus (sensory)
what are the functions of frontal lobe and what are the name and functions of the frontal lobe divisions
Function: movement, decision making, planning and problem solving
3 Divisions:
- Prefrontal cortex: personality expression, planning of complex cognitive behaviours
- Premotor cortex: planning of voluntary muscle movement
- Primary motor cortex (motor homunculus- motor homunculus shows where the upper motor neurons are for muscles of each part of the
body) – execution of voluntary movement
what is the Brocas area and where is it found
Associated with the motor aspect of speech
Found in the inferior frontal gyrus of frontal lobe
Found in the dominant hemisphere of the brain, left in most people
what happens if there is damage to the Brocas area
Expressive aphasia- non-fluent and slow speech
speech impaired; not fluent but can understand it
what are the functions of the parietal lobe
Associated with integrating sensory information
including sense of touch, pain, pressure, temperature and proprioception
where is the somatosensory cortex located and what are its functions
Parietal Lobe
The sensory homunculus shows where the third
order neurons in the medial lemniscal or
spinothalamic pathway terminate
what are the functions of temporal lobe, what are the divisions of temporal lobe and what structures of the limbic system does it contain.
Functions:
- Auditory perception
- Language and speech production
- Memory
Divisions (gyri):
- Superior
- Middle
- Inferior
Structures of the Limbic system:
- Olfactory cortex
- Hippocampus
- Amygdala
where is the primary auditory cortex found and what are its function
temporal lobe
responsible for processing auditory information.
what is the Wernicke’s area and where is it found
- Important for language development and comprehension of speech
- sensory language area, lexical processing
- Found in the superior temrporal gyrus
- Found in the dominant cerebral hemisphere – mostly left
what happens if there is damage to the Wernickes area
- Receptive aphasia
- Very Poor comprehension
fluent speech but no meaning
location and function of the hippocampus
- Located deep within the temporal lobe
- Associated with memory, particularly long-term memory
- Also plays a role in spatial navigation
location and function of the amygdala
- Almond shaped group of neurons that sits anterior to hippocampus
- Located in both hemispheres
- Primary role = emotion, experiences and memory
- Formation and storage associated with emotional events
what are the functions of the occipital lobe
- Main centre of visual processing (Posterior portions of parietal and temporal lobe are also involved in visual perception)
- Located within the occipital lobe = primary visual cortex (lies around the calcrine sulcus)
- This region receives input from retina via optic nerve
what is the insular cortex
- Portion of the cerebral cortex, folded deep in the lateral sulcus, can not be seen unless temporal lobe is pulled away but it is a cortical structure
- Linked with emotion and homeostasis
what structures is the basal ganglia made of and what are their functions
Divided into 3 parts:
- Corpus Striaum: made of Body of caudate nucleus, Putamen and Globus Pallidus. receives primary input for the rest of the basal ganglia i.e. receives glutamatergic
and dopaminergic input from
different sources.
- Sub-thalamic nuclei - produces glutamate
- Substantia niagra- Appears darker than neighbouring areas due to high levels of neuromelanin in dopaminergic neurons. Functions in: Eye movement, Motor planning, Reward seeking, Learning and Addiction
what is the basal ganglia
collection of nuclei that are strongly connected to the cerebrum, brainstem and cerebral cortex. It is involved in intiating planned motor activity and regulate this
Damage to corpus striatum and substantia niagra results in what disorders
Corpus Striatum- Huntingtons disease
Substantia Niagra- Parkinson’s disease
what is the lentiform nucleus
Comprised of Putamen and Globus Pallidus
what are the boundaries of the Lentiform nucleus
Medial border:
- Anterior limb of internal capsule
- Genu of internal capsule
- Posterior limb of internal capsule
Lateral border:
Claustrum
what is the internal capsule and what is it made of
White matter situated in each cerebral hemisphere which carries information past the basal ganglia, Carries:
- Third order afferent neurons from the
spinothalmic and dorsal lemniscal pathway (ascending)
- upper motor neuron from the corticospinal and
corticobubar pathway (descending)
Made of:
Anterior limb of internal capsule
Genu of internal capsule
Posterior limb of internal capsule
what is the difference between how sensory pathways (ascending) and motor pathways (descending) travel through the internal capsule
Sensory pathways (ascending) - Goes upwards into thalamus and then into cerebral cortex
Motor Pathways (descending) - Leaves the cortex and goes straight down and does not go into thalamus
what is the corpus callosum and what is it made up of
Enables communication between the two hemispheres of the brain, sits beneath the cerebral cortex and spans part of the longitudinal fissure - Composed of 4 parts: o Body o Splenium – posterior o Genu – anterior o Rostrum – inferior to genu
(see pics)
what is the ventricular system of the brain
Ventricular system of the brain is a set of 4 interconnected cavities in the brain that produce and contain CSF
what produces CSF
Within each ventricle is a region called the choroid plexus which produces CSF
Functions of CSF
Mechanical protection
Immunological protection to brain and spinal cord
what are the 4 ventricles and how are they connected to each other
4 ventricles:
o 2 bilateral ventricles
o 3 rd ventricle
o 4 th ventricle
- The lateral ventricles are connected to the 3 rd ventricle via interventricular foramen
- The third ventricle is connected to the 4 th ventricle via the aqueduct of midbrain
what is the thalamus
Mass of grey matter located deep in the cerebrum just above the brain stem
- Main function: Relay sensory signals to the cortex
- 3 rd order neurons for somatosensory tracts are found here
- regulates sleep, alertness and consciousness
what is the hypothalamus
- Found just below the thalamus
- Control centre for many autonomic functions of the peripheral nervous system
- Responsible for hunger, thirst and maintenance of body temperature
- Connections with structures of the endocrine and nervous system enable the hypothalamus to play a vital role in homeostasis
- Influences pituitary gland
what are the parts of the brain stem
Midbrain
Pons
Medulla Oblongata
what is the midbrain made of
Paired cerebral peduncles
Tectum
what is the positioning of paired cerebral peduncles and what parts does it contain
Anterior and lateral part of midbrain Further divided into: - Crus cerebri – anterior - Substantia nigra - Tegmentum
- They come off cerebral hemispheres to converge as they meet the pons (see pic)
- Optic tract runs around their border
what nerve exits superiorly between the cerebral peduncles
Occulomotor nerve
what is the structure of the tectum
Posterior Divided into: - x2 superior colliculus - x2 inferior colliculus Laterally to the colliculi are superior+inferior quadrigeminal brachium
what is the anatomical position of the pons
o Posteriorly is the cerebellum – separated by the fourth ventricle
o Inferior is the medulla
o Superior is the midbrain
From the anterior surface of the pons, there is emergence of 4 cranial nerves. Which one are these
- Trigeminal – lateral aspect of mid pons
- Abducens – lateral to the midline
- Facial - cerebellar pontine angle
- Vestibulocochlear – lateral to the facial nerve
- see pics*
what is the function of cerebellum
Role in motor control, posture, balance, coordination of movement and speech
How many hemispheres does the cerebellum have and what joins those hemispheres
2 hemispheres
Joined by vermis
Cerebellum is connected to the brainstem by 3 pair of cerebellar peduncles. what are they?
Superior peduncles – midbrain
Middle peduncles – pons
Inferior peduncles – medulla oblongata
what is the optic chiasm and what is it surrounded by
X shaped structure formed by the dessication of optic nerves.
Function- contralateral half of the visual field is perceived and processed by the visual cortex.
Optic chiasm is surrounded by the circle of Willis and derives its blood from the vessels forming this circle see pic
What is the pituitary stalk/infundibulum
Sits just inferior to the optic chiasm
Connection between hypothalamus and posterior pituitary
what is the arterial supply to brain
Circle of Willis
the brain arterial supply anastamose
Describe circle of willis
Found on posterior surface of brain
Main supply by internal carotid artery
From which cerebral arteries arise (anterior, middle and posterior)
see pics and be able to label internal carotid artery, basilar artery, vertebral artery and anterior,middle and posterior cerebral artery
Damage to the cerebral arteries result in what consequences
Damage to:
- Anterior cerebral artery- damage to frontal lobe + central sulcus
- Middle cerebral artery (lies underneath pterion)- damage to parietal+ frontal+temporal lobe
- Posterior cerebral artery- damage to occipital lobe- visual problems
