An Introduction to the brain and cranial nerves. Flashcards
The adult human brain contains almost 97% of the body’s ______ tissue.
neural
The brains of males are 10% ____ than females.
largest
Name the 6 regions of the brain.
cerebrum, cerebellum, diencephalon, midbrain, pons and medulla oblongata.
What is the largest part of the brain?
Cerebrum
What does the cerebrum control?
It controls higher mental functions
What is the cerebrum divided into?
Its divided into left and right cerebral hemispheres.
The brain has an extensive area of neural cortex called the ______ _______.
cerebral cortex
What covers the cerebral/neural cortex?
Grey matter
The cerebral cortex forms a series of elevated ridges called ________.
gyri
What is the function of gyri?
To increase the surface area
What are gyri separated by?
Shallow depressions called sulci.
Gyri can also be separated by deep grooves known as _____.
fissures
Name the second largest part of the brain.
The cerebellum
What is the function of the cerebellum?
To coordinate repetitive body movements
The cerebellum can coordinate _____ body movements by adjusting ongoing movements by comparing ____ _______ with _____ ______ sensations, allowing you to perform the same movements over and over.
repetitive, arriving sensations, previously experienced
The cerebellum exists in ____ hemispheres.
2
The cerebellum has hemispheres that are covered by a layer of gray matter. What is this called?
The cerebellar cortex.
Where is the diencephalon located?
Its located under the cerebrum and cerebellum
What is the function of the diencephalon?
it links the cerebrum with the brain stem
The ______ has 3 divisions.
diencephalon
Name the 3 divisions of the diencephalon.
Left thalamus, Right thalamus and the hypothalamus.
What does the thalamus do?
It contains relay and processing centres for sensory information.
Where is the hypothalamus?
It is at the floor of the diencephalon.
What contains centres involved with emotions, autonomic function and hormone production?
The Hypothalamus.
What is the pituitary gland?
it is a major endocrine gland.
Where is the pituitary gland connected to?
It’s connected to the hypothalamus via infundibulum (narrow stalk).
What are responsible for the integration of the nervous and endocrine systems?
The hypothalamus and the pituitary gland.
The _____ is a structural and functional link between the cerebral hemispheres and the components of the brain stem.
diencephalon.
What does the brain stem do?
It processes information between the spinal cord and cerebrum/cerebellum.
Name the parts of the brain stem.
Mid Brain
Pons
Medulla Oblongta
What does the mid brain process?
It processes sight, sound and associated reflexes.
The mid brain contains nuclei that process ____ and ______ information and control ____ triggered by these stimuli.
visual, auditory, reflexes
What does the mid brain maintain?
It maintains consciousness.
What is the function of pons?
To connect the cerebellum to the brain stem.
The pons contains nuclei involved in ___ and _____ ____ control.
somatic and visceral motor
The _____ _______ connects the brain to the spinal cord.
Medulla Oblongata
What is the function of the medulla oblongata?
It relays sensory information to the thalamus and to centres in other portions of the brain stem.
The medulla oblongata regulates ____ functions.
Autonomic functions
The medulla regulates autonomic functions, name 3.
heart rate, blood pressure and digestion.
The brain is a large, delicate mass of ______ tissue.
neural
Each of the brains ____ major regions has specific functions.
6
Ascending from the medulla oblongata to the cerebrum, brain functions become more _____ and ______.
complex, variable
Conscious thought and intelligence are produced in the neural cortex of the ______ hemispheres.
cerebral
Name three ways that the brain is physically protected.
bones of the cranium, cranial meninges and cerebrospinal fluid.
Name the biochemical isolation of the brain.
the blood-brain barrier
How many layers do the cranial meninges have?
3
Name the 3 layers of the cranial meninges.
Dura Mater
Arachnoid Mater
Pia Mater
The cranial meninges are continuous with what?
the spinal meninges.
What do the cranial meninges do?
They protect the brain from cranial trauma.
The dura mater is the _____ mater.
outer
Dura mater is made up of an _____ ______ _______ and an ____ _____ ______ (which is fused to the ______.)
Inner fibrous layer, outer fibrous layer, periosteum.
What is between the 2 layers of the dura mater?
Venous sinuses.
The arachnoid mater is the ____ mater.
middle
What does the arachnoid mater do?
It covers the brain, providing a smooth surface that doesn’t follow the brain’s underlying folds.
The arachnoid mater contacts the epithelial layer of ____ mater.
dura
What is between the arachnoid mater and pia mater?
subarachnoid space
What is attached to brain surfaces by astrocytes?
Pia Mater
What is the most inner mater of the cranial meninges?
Pia Mater
The folded inner layer of dura mater are known as _____ folds.
Dural
Dural folds extend into _____ activity.
cranial
What is the role of dural folds?
To stabilise and support the brain.
Dural folds contain collecting veins known as dural _____.
sinuses
Falx cerebelli, tentorium cerebelli and falx cerebri are all examples of what?
The largest dural folds.
What surrounds all exposed surfaces of the CNS?
Cerebrospinal fluid.
Name the functions of cerebrospinal fluid.
Cushions delicate neural structures
Supports the brain
Transports nutrients, chemical messengers and waste products
In essence the brain is _____ inside the ____ and floats in the __________.
suspended, cranium, cerebrospinal fluid (CSF).
A human brain ways about 3 lbs in ____ but only about 1.8 lbs when supported by the _________.
air, cerebrospinal fluid.
What are disorders that interfere with blood circulation to the brain known as?
Cerebrovascular Disease.
What are common cause of cerebrovascular disease?
Stroke- also known as cerebrovascular accident (CVA)
When does stroke occur?
When the blood supply to a portion of the brain is shut off.
What happens even in a matter of minutes if you have s stroke?
The affected neurons begin to die.
What does BBB stand for?
Blood-Brain Barrier
What does the blood brain barrier do?
It isolates CNS neural tissue from general circulation.
What is formed by a network of tight junctions between endothelial cells of CNS capillaries?
The Blood-Brain Barrier.
What sort of compounds can diffuse into interstitial fluid of the brain and spinal cord?
Lipid-soluble compounds
What are astrocytes?
cells that are in close contact with CNS capillaries and control the blood-brain barrier.
How do astrocytes control the blood brain barrier?
They release chemicals that control the permeability of the endothelium
What happens if astrocytes are damaged or stop stimulating the endothelial cells?
The blood brain barrier disappears.
What barrier is formed by special ependymal cells?
blood-CSF barrier.
The blood-CSF barrier limits movement of __________ transferred.
compounds
What does the blood-CSF barrier allow?
It allows the chemical composition of blood and CSF to differ.
What stabilises the position of the brain within the cranial cavity?
The cranial meninges
What provides protection against sudden jolts and shocks?
Cerebrospinal Fluid
The cerebrospinal fluid (CSF) provides ______ and removes ______.
nutrients, waste
What do the Blood–brain barrier and blood–CSF barrier both do?
They selectively isolate the brain from chemicals in the blood that might disrupt neural function.
Name the six major regions of the brain.
Cerebrum Cerebellum Diencephalon Midbrain Pons Medulla Oblongata
What brain regions make up the brain stem?
The Midbrain, Pons and Medulla Oblongata.
From superficial to deep, name the layers that make up the cranial meninges.
Dura mater (outer/superficial) Arachnoid mater (middle) Pia mater (deep/inner)
Many water-soluble molecules that are abundant in the blood occur in small amounts or not at all in the extracellular fluid of the brain. Why?
because the blood–brain barrier regulates the movement of such molecules from the blood to the ECF (extracellular fluid) of the brain. aka the barrier doesn’t let much in :)
