The Brain Flashcards
At what levels does Information processing takes place in the central nervous system?
Spinal cord = reflexes
Brainstem = reflexes
Higher brain = consciousness
What are the principal parts of the brain?
Brainstem
Diencephalon
Cerebrum
Cerebellum
What are the various protections and coverings of the brain pictured?
Cranial Bones
Meninges
- Dura Mater, arachnoid membrane, pia mater
- Dural sinuses: spaces within dura for CSF removal
- Dural extensions: separate parts of the brain, scicle shape
a. falx cerebri: separates cerebrum along sagital plane
b. falx cerebelli: separates cerebellum along sagital plane
c. tentorium cerebelli: separates cerebrum and cerebellum along transverse plane
Cerebrospinal Fluid (CSF)
-Shock absorption
What are the ventricles in the brain for and where are they located on the image?
cerebrospinal fluid made in the ventricles
- it contains nutrients and electrolytes to supply to brain
- continuously made and reabsorbed
What purpose does cerebrospinal fluid serve t maintain homeostasis?
Mechanical protection
-compression and shock absorption
Chemical protection
- ions and nutrients
- waste removal
Flows around cerebrum, cerebellum and between the two. Also flows down around brain stem through central canal
What is inolved in the cebrebrospinal fluid formation and removal?
Choroid Plexus
-located in the ventricle. where CSF is made
Arachnoid Villi
-located in dural sinuses. where CSF is reabsorbed
What structures make up the brainstem?
Medulla Oblongata, Pons Varolii, and Ventral/Dorsal Midbrain
What functions does the medulla oblongata serve? Where is it located?
Primitive functions ike brathing, blood pressure regulation, and swallowing reflex
Contains grey and white matter and many cranial nerves
What functions does the pons varolii serve? Where is it located?
Breathing pattern alterations
Contains greay and white matter
-also has tracts from spinal cord through medulla oblongata and pons
What makes up the ventral midbrain?
Cerebral peduncles
-descending tracts for motor output
Medial lemniscus
-ascending tracts for sensory input
Mostly white matter in ventral midbrain
What makes up the dorsal midbrain?
Corpora quadrigemina
- superior colliculi: mediates visual reflexes
- inferior colliculi: mediates auditory reflexes
Contains cranial nerves III and IV
What separates the dorsal and ventral midbrain?
4th ventricle
What is the reticular formation?
Web of gray matter running vertically through all levels of the brain
-contains association neurons that connects/filters infor to rest of the brain
What are the inputs/outputs to the reticular formation?
Inputs
-visual, auditory, general sensory like heat/cold
Outputs
-cerebral cotex via thalamus
What are the functions of the reticular formation?
- Somatic motor control
- Cardiovascular control
- Pain modulation
- Sleep and consciousness
- Habituation
- sensory adaptation
What is the thalamus?
Makes up 4/5 of the diencephalon
- all gray matter (association neurons)
- receives incoming sensory information, except smell, and then relays that information to the cerebral cortex
- 1st signs of crude perception: concsiousness/awareness
Contains
- paired nuclei: clusters of nuclei
- Intermediate mass: connects 2 halves of thalamus through 3rd ventricle
What is the hypothalamus?
Makes up 1/5 of the diencephalon
- all gray matter
- contains paired nuclei: clusters of nuclei
- controls homeostasis through pituitary gland
- hypothalamic nuclei contains centers that regulate biological needs
What is the epithalamus?
The pineal gland
- maintains biorhythms (circadian rhythm)
- secretes melatonin and serotonin along with 9 other hormones
Connected to visual cortex
-require light and darkness to release different hormones
What are the functions of the cerebellum?
Control of smooth, sequential, and coordinated skeletal muscle
- posture and muscle tone
- coordinated movement
- also time keeping and checking inappropriate behavior
What is the cerebellar white matter called?
arbor vitae or ‘‘tree of life’’
What are the features of the cerebrum pictured?
What is the cerebral cortex?
outer layer of cerebrum
- composed of grey matter only
- collection of cell bodies
What is the internal capsule?
the white matter in the cerebrum
What is the corpus callosum?
90% of tracts from right to left hemisphere contained in corpus callosum
-communication between hemispheres
What are the lobes of the cerebrum and what is their function?
- Frontal: creative, planning, executive function
- Parietal: general sensory info
- Temporal: speech, hearing, equilibrium
- Occipital: visual input
- Insula: learning, smell
What makes up the cerebral white matter?
- Association fibers: gyrus to gyrus on same hemisphere
- Commisural fibers: gyrus to gyrus on opposite hemispheres
- Projection fibers: leave cerebrum to transmit signals to skeletal muscle
What is the cerebral nuclei?
AKA Basal Ganglia
- control of semi-voluntary movements and muscle tone
- begins voluntary but cerebral nuclei takes over making it semi-voluntary
- learned movements like walking/riding bike = muscle memory
What is it called when gray matter singals other gray matter in a different hemisphere?
decussating
What structures make up the cerebrum?
Lobes of the cerebrum
Cerebral nuclei
Limbic system
- amygdala
- hippocampus
What is the limbic system?
Reptilian brain
-emotion, smell, memory
in the insula lobe
Contains
- amygdala: memory+emotion
- hippocampus: memory+learning
What are the primary sensory areas, primary motor areas and association areas of the cerebrum?
Primary sensory areas
- somatosensory area, visual area, auditory area
- sensory input from receptors
Primary motor areas
-motor output down through spinal cord to limbs
Association areas
-allow you to remember sensory stimuli
