Chapter 14 The Brain Flashcards
Sections of the Brain:
1) Cerebrum
2)Cerebellum
3)Diencephalon
4) Brain Stem
4) Brain Stem
A. Mesencephalon –Meso middle or mid brain.
-Processes visual and auditory information (stimuli); reflexive responses to a loud noise which causes eye/head to turn are directed by this area
B. Pons -(metencephalon)- Bridge
-Connects cerebellum to the brain stem; involved with somatic
and visceral motor control.
C. Medulla Oblongata -(myelencephalon) -Relays sensory information to the
thalamus; regulates heart rate, blood pressure, and digestion.
-Continuation of the superior part of spinal cord
brain weighs
3 pounds
male’s being about 10% larger than females
Cerebrum
Conscious thought, Memory Stoage and Processing,
Conscious and unconscious process of skeletal muscles
-Largest section of the brain.
-Divided into (a) right cerebral hemisphere and (b) left cerebral hemisphere.
-Covered by “neural cortex”, which is a superficial layer of gray matter
Cerebellum
Coords complex Somatic Motor Commands
Adjusts output of Somatic Motor In the Brain and Spinal Cord
-Second largest section of the brain.
-Coordinates skilled movements (dancing, running) and regulates posture and balance.
Diencephalon
Thalamus : Relays and processes sensory signals
Hypothalamus: Controls Emotions, Autonomic sys, Hormone Production
Composed of:
(a)Thalamus
(b)Hypothalamus – located on floor of diencephalons; responsible for emotions and hormone production.
(c) Pituitary gland
Mesencephalon
Visual and Audio, Somatic Motor Reflex, Maint of Consciouness
Pons
Relays Sensory, Subconscious Somatic and Viseral Motor
Medulla Oblongata
senory to Thalamus and brain stem, Autonomic for regulation of Visceral sys (cardio, resp and digestive)
Ventricles are “compartments” lined with ependymal cells.
-Lateral ventricles (ventricles 1 and 2) communicate through “interventricular foramen” or “foramen of monro”.
-Third ventricle is located in the diencephalon. 3rd Ventricle is attached to 4th ventricle by “mesencephalic aquaduct”.
-Fourth ventricle attaches to the central canal of spinal cord.
-Ventricles are filled with CSF
CEREBROSPINAL FLUID:
CSF Functions:
-cushions delicate neural structures & balances pressure.
-supports the brain keeping it floating inside of skull.
-transports nutrients, chemical messengers and removes waste products.
-primarily made up of saline solution
CSF Formation:
Choroid plexus
- Consists of ependymal cells and permeable capillaries for production of CSF.
- Ependymal cells:
surround the capillaries of the choroid plexus.
secrete CSF into the ventricles of brain.
remove waste from CSF.
150 mL of CSF in adult brain and is replaced about every 8 hours.
CSF circulates from the choroid plexus through ventricles and central canal of spinal cord.
CSF is absorbed by arachnoid villi and sent to the venous circulation as waste
CSF Formation (cont.):
Choroid plexus
The blood-brain barrier (BBB) – CSF is isolated from blood in the brain to prevent materials from getting into CSF.
Closely packed cells prevent large molecules (RBCs) from passing but allows things that can pass through the cell membranes to pass (O2).
CO2, O2, NH3, lipids, steroids, and alcohol can pass from blood, through cells and into CSF.
Na+, H+, K+, Cl-, norepinepherine, dopamine, and serotonin can pass but are highly regulated.
CSF is found in the brain between the arachnoid and pia meninges and throughout the ventricles
Cranial meninges:
This provides protection to the brain.
Consists of:
Cranial dura mater - consists of outer (endoseal layer) and inner fibrous (Meningeal layer) layers. Outer layer is fused to the cranial bone while inner layer is attached to subdural space. Dura mater also contains dural folds which act like seat belts that keep brain attached inside of skull.
Dural Folds - this provides additional support and stabilization of the brain.
a. Falx cerebri - located between the cerebral hemispheres in the longitudinal fissure.
b. Tentorium cerebelli - separates and protects the cerebellar hemispheres from those in cerebrum.
c. Falx cerebelli - divides two cerebellar hemispheres along the midsagittal line
Cranial meninges:
Cranial arachnoid layer - covers the brain creating a smooth surface.
- Pia mater - innermost layer that attaches to the brain and extends into every fold
Cerebral Cortex –
has 2 hemispheres (left and right) separated by longitudinal fissure but connected by “corpus callosum”.
Lobes are divisions of the cerebral hemispheres that are named after overlying skull bones. All lobes integrate and process sensory information and initiate motor commands.
4 Lobes:
1) Frontal Lobe – primary motor cortex; voluntary control of skeletal muscles.
2) Parietal Lobe – primary sensory cortex; perceives touch, pressure, pain, taste, and temperature.
3) Temporal Lobe – auditory and olfactory cortex; perceives hearing and smell.
4) Occipital Lobe – visual cortex; perceives visual stimuli
Hemispheres:
-Each hemisphere receives sensory and sends motor commands to opposite side of the body (no one knows why the crossover exists).
Cerebrum is divided into two hemispheres by the longitudinal fissures.
1)Left Cerebral Hemisphere – reading, writing, math, logic, and speaking are dependent on processing done in this region.
2) Right Cerebral Hemisphere – emotions and recognizing faces are dependent on processing done is this region. These people are creative and are good at art
Motor and Sensory Areas of the Cortex:
1)Pre Central Gyrus – (part of frontal lobe) contains the “primary motor cortex”.
2)Post Central Gyrus – (part of parietal lobe) contains the “primary sensory cortex”
CRANIAL NERVES- are PNS components that connect directly to the brain.
Nerve Primary Function 1) Olfactory Smell 2) Optic Vision 3) Oculomotor Eye movements 4) Trochlear Eye movement 5) Trigeminal Mixed sensory and motor to face 6) Abducens Eye movement 7) Facial Mixed sensory and motor to face 8) Vestibulocochlear (Auditory) Hearing and balance 9) Glossopharyngeal Mixed to head and neck 10) Vagus Mixed to thorax and abdomen 11) Spinal Accessory Motor to neck and upper back 12) Hypoglossal Motor tongue movements
CRANIAL NERVES-
On 1 S
Old 2 S
Olympus 3 M
Towering 4 M
Tops 5 B
A 6 M
Finn 7 B
And 8 S
German 9 B
Viewed 10 B
Some 11 M
Hops 12 M
