The Brain I Flashcards
Name the three coverings of the brain
Dura Mater
Arachnoid Mater
Pia Mater
What is the singular of meninges?
meninx
Physically describe the dura mater
Thick as a rubber glove
Fibrous outer layer made from dense, irregular CT
What does dura mater mean?
“Tough Mother”
What are the two layers of the dura mater?
2 layers, usually fused
Meningeal layer: near the meninges
Periosteal layer: near the bone
What is a dural sinus?
In certain areas, gaps that form between the meningeal and periosteal layers
Physically describe the arachnoid mater
A transparent membrane over the surface of the brain
Provides a smooth surface that does not follow the brain’s underlying folds
What does arachnoid mater mean?
“Spider” mater
How does the arachnoid mater connect to the pia mater?
With delicate threads
What does pia mater mean?
Delicate mother
Physically describe the pia mater
A thin, transparent layer
It adheres to the surface of the brain
Not removable
How is the pia mater anchored to the brain?
By the processes of astrocytes
The brain weights _______ grams and is protected by _______.
1,200
The cranial bones
How does the brain grow in the first year of life and what is this process called?
Mainly due to the increase is size of cells already present, this is called hypertrophy
What are the 4 subunits of the brain?
Cerebrum
Diencephalon
Cerebellum
Brain stem
What three parts make up the diencephalon?
Thalamus
Hypothalamus
Epithalamus
What three parts make up the brain stem?
Midbrain
Pons
Medulla oblongata
If you touch a hot stove, the _______ _______ keep you safe while the brain is processing information.
Spinal reflexes
The cerebrum is made from 2 ________ ________ and composes the _______ of the brain
Cerebral hemispheres
Bulk
The cerebrum accounts for ____% of the weight of the brain.
60%
The surface of the cerebrum is made of _____ matter and forms the _______ ________.
Gray
Cerebral cortex
Gray matter is composed of ________ _______ _______.
Neuronal cell bodies
Gray matter is ______mm thick and contains billions of neurons and __________ fibers.
2-4 mm
unmyelinated
What part of the brain does intelligence, memory, creativity, and the ability to read, write, speak, calculate, compose music, etc come from?
Cerebrum
What is white matter and why is it white?
Lies underneath gray matter and is bundles of parallel axons and their sheaths- the white color comes from the myelin in the sheath
Physically what is white matter composed of
Consists of dendrites, myelinated axons and associated neural glia
What is gyrus?
Elevated fold of gray matter
What is sulci?
Shallow depressions between the gyri
What is a cerebral fissure? Where is one found in the brain?
Deep grooves
The two cerebral hemispheres are separated by a longitudinal fissure
How to gyri form?
During embryonic stages there is a rapid increase in brain size and the gray matter enlarges faster than the white matter, so the cortical area (cortex) rolls and folds over itself
What are the three folds of dura mater that extend into brain fissures?
Falx ceribri
Falx cerebelli
Tentorium cerebelli
What is the falx cerebri and what does it contain?
n the longitudinal fissure between the cerebral hemispheres
Contains the superior and inferior sagittal sinuses
What is the falx cerebelli?
Between the hemispheres of the cerebellum
Not very deep
What is the tentorium cerebelli and what does it contain?
Between the cerebrum and the cerebellum
Contains the transverse and straight sinuses
How are the falx like seat belts?
The falx are “seat belts” of dura mater that holds the brain in place.
What are the four lobes of the cerebrum and how are they named?
The lobes of the cerebrum are named for the bones covering them 1- Frontal 2- Parietal 3- Temporal 4- Occipital
The ______ _______separates the frontal lobe from the parietal lobe
Central sulcus
What is the motor cortext?
The precentral gyrus
What is the sensory cortex?
The postsentral gyrus (Think of the S in sensory and s in post)
The ______ _______separates the temporal lobe from the rest of the cerebral hemisphere
lateral sulcus
What is an association fiber?
Connect and transmit nerve impulses between gyri in the same hemisphere
What do long association fibers connect?
Connect different lobes
What do short association fibers connect?
Connect different gyri in the same lobe
What is a commissural fiber?
Connect 1 gyrus in a hemisphere to the corresponding gyrus in the opposite hemisphere
What is the corpus callosum? And spell.
Contains over 200 million axons, carrying 4 billion impulses/second
Made of commissural fibers
What is a projection fiber?
These form the descending and ascending tracts that transport impulses between the cerebellum and other parts of the brain and spinal cord and body
What are the basal nuclei?
Masses of gray matter (groups of nuclei) are located deep within each cerebral hemisphere
What do the basal nuclei control?
They control coordination of muscle groups that function together to perform voluntary motion, determining the onset and cessation of intentional movements and highly practiced, learned behaviors
eg walking, tying shoes, using scissors, typing
How does damage to the basal nuclei manifest in a patient? What is an example of a disease that does this?
If this area is damaged, pts will have a difficulty rising from a chair and starting to walk. Pt will have a slow, shuffling gait or will have exaggerated or unwanted movements such as flailing of the limbs.
You also have trouble with antagonistic muscles not being inhibited.
e.g. Parkinson’s
What is the limbic system?
A ring of structures on the inner border or cerebrum and the floor of diencephalon
The limbic system is a _________ grouping rather than an ________ grouping.
Functional
Anatomical
What are the functions of the limbic system?
Functions in emotions and behavior: pleasure, anger, rage, fear, sorrow, sexual feelings
The limbic system establishes ________ states and facilitates _________ storage and retrieval.
emotional
memory
What functions does the cerebrum perform?
Performs motor, sensory, and integrative functions.
Generally, the motor and sensory functions are controlled by centers in the cerebral hemisphere on the _______ side.
Opposite
The centers for control of the left leg are in the ______ brain.
Right
Sensory crosses over to the _______ thalamus and proceeds up.
contralateral
Speech is associated with the ______ lobe, while vision is associated with the _______.
Frontal
Occipital
Hearing and olfactory are both associated with the _______ lobe.
Temporal
The left hemisphere of the cerebrum is associated with:
categorical hemisphere, specialized for:
spoken and written language
sequential and analytical reasoning; science and math
The right hemisphere of the cerebrum is associated with:
Right hemisphere: representational hemisphere, specialized for:
perceiving information in a more integrated, holistic way
imagination, insight, musical and artistic skill
It helps identify familiar objects by touch, smell, sight, taste and feel
Memory is associated with the _________ system and is still being _______.
Limbic
Researched
Anterograde amnesia is:
Impaired ability to learn new info following onset of amnesia
Retrograde amnesia is:
Impaired ability to recall info from before onset of amnesia
