The Brain Flashcards
Cerebellum
Posterior to the brain stem “little brain”
Diencephalon
Superior to the Brain stem; consists of the thalamus, hypothalamus, and the epithalamus
Cerebrum
Superior to the brain stem diencephelon. It is the largest part of the brain
Protective coverings of the brain
Dura mater
Arachnoid mater
Pia mater
Dura mater
Most superficial meninge (protects the brain)
Thin layers within the dura mater: falx cerebri, falx cerebelli, and tentorium cerebelli
Arachnoid mater
Middle layer of the meninges. Contains arachnoid villi. Separated by subdural space
Pia mater
Deepest and thinnest layer attached directly to the brain. Covers every fold of the brain and supports blood vessels
Subarachnoid space
Pia mater is separated from the arachnoid mater by subarachnoid space. Usually filled with cerebral spinal fluid.
Brain stem
Continuous with the spinal cord; consists of the ,emulate oblongata, pons, and midbrain
Meningeal spaces
Epidural space- potential space between the skull and the dura. Only in the spinal cord
Subdural space- real space between the dura and arachnoid. Contains small bridging veins
Subarachnoid space- real space between the arachnoid and pia mater. Contains cerebrospinal fluid
Arterial brain flow (anterior)
Anterior: (provides the cerebrum with blood)common carotid arteries–>internal carotid arteries–>base of skull–> cranium–> branch to anterior and middle cerebral arteries
Arterial Brain blood flow (posterior)
Posterior: (provides the brain stem with blood) subclavian arteries–> vertebral arteries–> transverse foramina of cervical vertebrae–> foremen magnum. Joins at the junction of pons and medulla–> basilar artery–> pontine branches. Posterior cerebral arteries–> anterior inferior cerebellar and superior cerebellar arteries. Vertebral artery–> posterior inferior cerebellar artery.
Venous blood flow
Brain sinuses- venous channels that are found between layers of dura mater.
Veins of brain–> sinuses–> internal jugular vein–> brachiocephalic vein–> superior vena cava–> right atrium
Blood- brain barrier
Protects brain cells from harmful substances and pathogens. It does this by acting as a selective barrier to prevent passage of many substances from the blood to the brain.
Found around brain capillaries
Cerebrospinal fluid
Clear, liquid (similar to blood plasma)
Protects the brain and spinal cord against chemical and physical injuries.
Carries O2, glucose
Ventricles and where they are located
Lateral ventricles: (2). One located in each cerebral hemisphere
Third Ventricle: located in the middle of the diencephelon
Fourth Ventricle: located between the Bain stem and cerebellum.
Brain stem
Located between the spinal cord and diencephelon
Consists of medulla oblongata, pons, and midbrain
Medulla oblongata
Most inferior brain stem part Contains sensory (ascending) tracts and motor (descending) tracts carrying information to and from the spinal cord.
Cardiovascular center
Part of the medulla oblongata
Regulates heartbeat, blood vessel diameter and blood pressure
Medullary rythmicity
Part of the medulla oblongata Regulates breathing (with pons)
Reticular foremen
Found in medulla oblongata, pons, midbrain and diencephelon
Function: consciousness and arousal
Pons
Middle of the brain stem. Located between the medulla oblongata and midbrain.
Contains sensory and motor tracts relaying information to and from the medulla oblongata, cerebellum and higher brain centers
Midbrain
Uppermost part of the bainstem. Connects to the diencephelon
Contains sensory and motor tracts
Cerebral peduncles
Motor tracts enter the midbrain from higher brain centers via the cerebral peduncles
Cerebellum
Contains over half the neurons of your brain. Communicates with the brainstem, higher brain centers and spinal cord via cerebellar peduncles.
Functions: smooths and coordinates skeletal muscle contractions, regulates posture and balance, plays a role in language processing
Folia
Outer gray matter of the brain is organized into folia
Arbor vitae
Inner white matter is organized into arbor vitae
Diencephelon
Extends from brainstem to cerebrum
Surrounds the 3rd ventricle
Contains the thalamus, hypothalamus, and epithalamus
Vermis
Part of the cerebellum
Connects the 2 lobes of the brain
Thalamus
Located superior to midbrain
Functions: plays a role in maintenance of consciousness, relays almost all sensory input to cerebral cortex
Hypothalamus
Located inferior to the thalamus
Controls and integrates ANS activities
Produces hormones
Regulates emotional and behavioral patterns
Epithalamus
Lies superior and posterior to the thalamus
Contains the pineal gland
Pineal gland
Part of the epithalamus
Secretes melatonin to influence diurnal cycles (with the hypothalamus)
Cerebrum
Composed of two cerebral hemispheres separated by a longitudinal fissure
Corpus callosum
Both hemispheres of the brain are connected internally with the corpus callosum
Lobes of the cerebrum
Frontal, parietal, temporal, and occipital (all can be seen externally)
Cerebral cortex
The outer layer of the cerebrum
Organized into gyri, sulcus and fissures
Gyri
Part of the cerebral cortex.
They are a coil/twist(may be a multiple)
Includes: precentral gyrus and postcentral gyrus
Sulci
Shallow grooves in the cerebrum
Includes: central sulcus and later al cerebral sulcus
Fissures
Deep grooves in the cerebrum.
Includes: longitudinal fissure and transverse fissure
White matter of the cerebral cortex
Located underneath the cerebral cortex
Connect parts of the brain with itself and other parts of the nervous system
White matter fibers
Association fibers: connect and transmit nerve impulses between gyri in the same hemisphere
Commussural fibers: connect gyri in one vertebral hemisphere to corresponding gyri in the opposite hemisphere
Projection fibers: from ascending and descending tract that transmit impulses from the cerebrum to other parts of the brain and spinal cord.
Basal ganglia
3 large nuclei located deep within the white matter of each cerebral hemisphere
Functions: help initiate and terminate body movements
Suppress unwanted movements and regulate muscle tone
