Functional anatomy of The Brain Flashcards
What derived brain structure makes up the Telencephalon?
The Cerebrum
What derived brain structures make up the Diencephalon?
Thalamus and the Hypothalamus
What derived brain structures make up the Mesencephalon?
The midbrain
What derived brain structures make up the metencephalon?
The pons and the cerebellum
What derived brain structures make up the Myelencephalon?
The medulla oblongata
What divides the cerebral hemispheres into two?
The longitudinal cerebral fissure
What are the names of the outward and inward folds found on each hemisphere?
gyri (ridges) and sulci (grooves)
What is the function of the cerebrum?
It initiates voluntary skeletal muscle movements, stores memory, voluntary motor control, behaviour and mental status
What makes up grey matter in the brain?
Grey matter is made up of neuronal cell bodies
What are the basal nuclei?
Masses of grey matter located deep in the brain (hippocampus), responsible for musculoskeletal activity
What makes up white matter?
White matter is made up of myelinated nerve fibres
What are three different types of white matter fibres?
Association fibres, Commissural fibres and projection fibres
What are association fibres?
Fibres that connect adjacent gyri (cell bodies lie in the cortex)
What are commissural fibres?
Fibres that connect the two hemispheres (corpus callosum is the region containing these fibres), cell bodies lie in the cortex (grey matter)
What are projection fibres?
Fibres that connect the cortex with other parts of the brain/spinal cord (more or less vertically)
What are some characteristics of the cerebral cortex?
It is acquired late in vertebral evolution, most complex/ integrating area of the brain and it is concerned with those nervous reactions that result in consciousness
What are the 3 main sections of the cerebral cortex?
Motor cortex, Sensory cortex and association cortex
What is the function of the motor cortex?
Initiates non-reflex movements, it is contralateral
What is the function of the sensory cortex?
Deals with sensory perception
What is the function of the Association cortex?
It is the site of complex memory integration, planning, self-awareness, language and personality traits
What are the functional lobes of the cerebrum?
Frontal, occipital, parietal, temporal and piriform
What does the frontal lobe contain?
It contains part of the motor cortex associated with voluntary movement
What does the occipital lobe contain?
The occipital lobe functions as a visual cortex
What does the parietal lobe contain?
The somato-sensory cortex (controls localisation of pain, touch and temperature)
What is the function of the temporal lobe?
Has an auditory function as well as behaviour and memory
What is the piriform lobe associated with?
Associated with conscious olfaction, it receives olfactory input from the olfactory bulb
What structures make up the brain stem?
The mesencephalon (midbrain), ventral metencephalon (pons), the Myelencephalon (medulla oblongata) and the Diencephalon (thalamus and hypothalamus)
What is the name of the ventricle that separates nuclei in the diencephalon?
The Third Ventricle
What are the four regions of the diencephalon?
Thalamus, Hypothalamus, epithalamus and and subthalamus
What is the interthalamic adhesion?
Band of connective tissue that connects both sides of the thalamus
What occurs on the ventral side of the thalamus?
Optic nerves form the optic chiasm of the diencephalon
What nerve runs rostral to the optic chiasm?
The optic nerve
What is the function of mesencephalon/ midbrain?
It connects lower brain centres/ the spinal cord with higher brain centres
What is the larger rostral colliculus?
a visual reflex centre
What is the smaller caudal colliculus?
an auditory reflex centre
Where does the oculomotor nerve (cranial nerve 3) arise from?
The oculomotor nerve arises from cerebral peduncles just caudal to the mammillary body
Where does the trochlear (cranial nerve 4) arise from?
From the caudal colliculli
What does the mesencephalic aqueduct connect?
The mesencephalic aqueduct is a ventricular tube that connects the third and fourth ventricles
What nerve does the ventral metencephalon (pons) give rise to?
The rostral end contains the forth ventricle and gives rise to the Trigeminal nerve (cranial nerve 5)
What are cerebellar peduncles?
Structure that connects the cerebellum to the brainstem and cerebrum
What is the function of the cerebellum?
maintenance of balance and coordination, controlling/adjusting body movements
How many cranial nerves does the medulla oblongata give rise to?
7/12
What is the Dura mater?
The thick outer layer of the brain (fibrous)
What is the arachnoid layer of the brain?
The thin middle layer, it is made up of non-vascular connective tissue with fine filaments that connect the subarachnoid space with the pia mater
What is the pia mater layer of the brain?
The innermost, vascular layer, it firmly attaches to the underlying nervous tissue
What two meninges contain the leptomeninges?
The arachnoid and pia mater
What is the space between the pia mater and arachnoid?
The subarachnoid space, it is full of CSF and contains a fine network of connective tissue fibres that originate from the arachnoid
Where are the ventricles of the brain derived from?
They are derived from the fluid-filled centre of the embryonic neural tube
What are the ventricles of the brain?
A series of interconnected cavities in the core of the brain that have an ependymal cell lining and are filled with CSF
How many ventricles does the cavity form?
Four
What is the name of the two most rostral ventricles?
Lateral ventricles (first and second0
What is the function of the interventricular foramen?
Connects the lateral ventricles with the third ventricle
What does the caudal end of the fourth ventricle merge with after it narrows?
The central canal
What produces CSF?
small arterioles and arteries in the leptomeninges and choroid plexus in the ventricles
What are the three main routes that CSF is drained from the brain?
Venules of the subarachnoid space, by the lymphatic vessels and into venous sinuses of the brain
What is the function of cerebrospinal fluid?
It gives the brain buoyancy/support- protects the brain from trauma and helps to provide the brain with nutrients
Where does the sensory olfactory nerve run from?
It runs from the nasal cavity to the olfactory bulb on the ventral side of the cerebrum
Where does the sensory optic nerve run from?
It runs from the eyes to the thalamus
Where do the arteries that supply the cerebrum and cerebellum come from?
They are branches of vessels found on the ventral side of the brain
Where does all species blood pool before entering the brain?
The circle of willis
What are the 4 main arteries that supply blood to the brain?
Internal carotid, Maxillary, Basilar and Vertebral
Where does the basilar artery come from?
The vestibular artery
What artery originates from the basilar artery?
The caudal cerebellar
What four arteries arise from the cerebral arterial circle?
The rostral, middle and Caudal cerebral, and the rostral cerebellar
What artery supplies the cerebral arterial circle in the sheep and cat?
The maxillary artery (via the rete mirabile after it anastomoses with the internal carotid artery)
What artery supplies the medulla oblongata in the sheep and cat?
The vertebral artery
Where does the cerebral arterial circle receive blood from in the ox?
Internal carotid, Maxillary, occipital and vertebral arteries
What is the function of the brain ventricles?
To produce and secrete cerebrospinalfluid
