The Brain Flashcards
Name the different lobes of the brain
- Temporal
- Frontal
- Parietal
- Occipital
Name the 3 general portions of the brain
- Cerebrum
- Cerebellum
- Medulla
What is the cerebrum composed of
2 cerebral hemispheres
Name the fissure that travels down the midline of the brain; and what artery is present
Longitudinal fissure; anterior cerebral arteries
What are the lumps and grooves of the brain called
Lumps = gyrus Grooves = sulcus
What fissure separates the temporal lobe with the parietal and frontal lobes; and what artery is present
Lateral fissure; middle cerebral artery
What is the corpus callosum
White matter tract that connects the cerebral hemispheres
What is the main action of the basal ganglia
Regulate initiation and termination of body movements
What 3 structures form the diencephalon
- Thalamus
- Hypothalamus
- Pineal gland (epithalamus)
Where do fibres come from to pass through the thalamus
Spinal cord, brainstem and midbrain
What does the pineal gland produce
Melatonin, which regulates our body clock
What is the main action of the hypothalamus
Regulation of the ANS and homeostasis
What gland is the hypothalamus in association with
Pituitary gland
What structure does the pituitary gland communicate with the rest of the brain with
Pituitary stalk
What hormones does the pituitary gland release
- Growth hormone
2. Follicle stimulating hormone and luteinising hormone
Where is the midbrain located
Junction of the middle and posterior cranial fossae
What does the midbrain connect
Diencephalon with the pons and medulla
Name the small lumps of tissue within the brainstem that are associated with the visual and auditory systems
- Superior colliculi = visual tracking and scanning
2. Inferior colliculi = auditory startle reflex
What does the midbrain connect
Diencephalon with the pons and medulla
What cranial nerves originate from the midbrain
- CN III = occulomotor
2. CN IV = trochlear
Name the features of the midbrain that control body movement
- Substantia nigra = controls subconscious muscle action
2. Red nuclei = co-ordinate muscle movement
What cranial nerves originate from the pons
- CN V = trigeminal
- CN VI = abducent
- CN VII = facial
- CN VIII = vestibular part of the vestibulocochlear (balance)
What is the function of the pontine nuclei
- Coordinates and maximises voluntary motor output
2. Controls our breathing pattern
Where is the medulla oblongata located
Posterior cranial fossa; most caudal subdivision of the brainstem that is continuous with the spinal cord
What is the function of the medulla’s olives
Proprioception; joint and muscle position
What cranial nerves originate from the medulla oblongata
- CN IX = glossopharangeal
- CN X = vagus
- CN XI = accessory spinal
- CN XII = hypoglossal
- CN VIII = cochlear part of the vestibulocochlear (hearing)
Describe the location of the cerebellum
Beneath the tentorium cerebelli in the posterior cranial fossa
What is the cerebellum composed of
Two lateral hemispheres (lobes) united by a narrow middle part, the vermis
What are the main actions of the cerebellum
- Controls subconscious aspects of skeletal muscle movements
- Regulates posture and balance
Describe the communication pathways of the cerebella peduncles
- Superior = midbrain to cerebellum
- Middle = pons to cerebellum
- Inferior = medulla to cerebellum
Name the primary arteries supplying the brain
- Internal carotid
2. Vertebral
Where do the internal carotid arteries enter the cranial cavity
Through the carotid canal in the petrous part of the temporal bone
Name the terminal branches of the internal carotid arteries
- Anterior cerebral arteries
2. Middle cerebral arteries
What is formed, and where, when the vertebral arteries unite
At the caudal border of the pons the basilar artery is formed
What are the terminal branches of the basilar artery
Posterior cerebral arteries
What arteries form the circle of Willis
- Anterior cerebral
- Anterior communicating
- Posterior cerebral
- Posterior communicating
What are the meninges
The three membranes that envelop the brain and spinal cord; dura, arachnoid, and pia mater
What space contains the CSF
Subarachnoid space (between arachnoid and pia mater)
Describe the arterial supply to the meninges, and where they originate from
- Anterior meningeal artery; ethmoid branches
- Middle meningeal artery; maxillary artery
- Posterior meningeal artery; occipital artery
What is the function of the dural venous blood sinuses
Drain blood from the brain and channel it in into the internal jugular vein
Describe the location of the sinuses
- Between periosteum and dura
OR - Between two layers of dura
Describe the communications of the dural venous sinuses
- Cavernous venous sinus
- Pterygoid venous plexus
- Opthalmic and facial veins
What cells produce CSF, and how is it secreted
Ependymal cells produce it; secreted by the choroid plexuses of the ventricles
What does CSF provide
Mechanical and physical protection to the brain and spinal cord
How does CSF enter the subarachnoid space
Through small apertures in the brain’s 4th ventricle
How many ventricles does the brain have
4
What do the lateral ventricles open into to reach the 3rd ventricle
Interventricular foramen
What connects the 3rd and 4th ventricles
Cerebral aqueduct
Describe the location of the 3rd ventricle
Between the right and left halves of the diencephalon; inside the thalamus
Where is the 4th ventricle located
Posterior part of the pons and medulla
What apertures are present in the 4th ventricle
- Single median aperture
2. Paired lateral apertures
