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Front Back
toward the head end of the animal
structures located toward the tail end of the animal
Structures located toward the belly side of an animal
Structures located to the backside of an animal
an imaginary line that runs the length of the spinal cord through the brain.
Imaginary line that cuts a human body roughly in half
Structures located on the same side of the midline
Structures located on opposite sides of the midline
Structures close to the midline
Structures located away from the midline
Close to the center
Far away from the center
3 major planes of section
Coronal, Sagittal, horizontal.  These planes take 3D structures and put them on a page.
Coronal Sections
Also known as frontal sections, divide the nervous system from front to back.  You are looking at the brain in the face.
Sagittal Sections
Parallel to the midline, allowing a side view of brain structures.
Midsagittal section
The special section that divides the brain into two elatively equal halves.  Obviously part of the sagittal section.
Horizontal or axial section
Divides the brain from top to bottom.
A layer of membranes that surround the nervous system. (All three layers cover the brain and spinal cord.)
Dura Mater
Literally means "hard mother" in Latin.  The outermost layer of of meninges.  Leather-like and follows the curve of the skull. (under it)
Arachnoid Layer
Below the dura mater layer.  More delicate.  Looks like a spider web with it's cross-sections.
Pia Mater
Innermost layer (below arachnoid layer) Nearly transparent layer that sticks to the outside of the brain.
Subarachnoid Space
Between arachnoid layer and pia mater.
Cerebrospinal fluid (CSF)
Secreted within hollow spaces in the brain known as ventricals.  Essentially helps the brain float and cushions it against impact.  It hides the brain from pressure which can cause neurons to fire wrong signals and harm the brain and body.
Choroid Plexus
Within the lining of the ventricals, this converts material from nearby blood supply into CSF
Central Canal
Small midline channel in the spinal chord that contains CSF
Four: 2 lateral ventricles, 3rd and 4th.  Cerebral aqueduct connects 3rd and 4th ventricle
Where is CSF produced?
Choroid Plexus
How does CSF flow?
From 2 lateral ventricles, to the third ventricle, to the fourth ventricle, to the central canal of the spinal cord.  Also flows in the subarachnoid space.
Where does CSF go when it's replaced?
From the top of the skull to be reabsorbed into the blood stream
What is Hydrocephalus?
"Water on the brain".  Caused by obstuction or abnormality that impedes the normal flow of CSF.  It causes increased pressure withint ventricles.  Can be treated by surgically inserting a shunt that acts as a valve to drain off the extra csf.
What % of blood does the brain use?
20% of blood is used by the brain which is 2% of our body mass. (energy requirements)
How does the brain recieve blood?
Through the carotid and vertebral arteries.  They bring it to the skull and branch off into other arteries to supply blood to the brain.
What causes a stroke?
Blockage or break in a cerebral artery.
What is the Circle of Willis?
A circle where the 3 cerebral arteries (anterior cerebral artery, middle cerebral artery, posterior cerebral artery) join.  It provides an alternative route for blood to flow if any of the other arteries become blocked or break.  Compensatory mechanism.
What are the two divisions of the nervous system?
The Centeral Nervous System and the Peripheral Nervous System
What is the CNS
brain and spinal cord
What is the PNS?
nerves from the brain and spinal cord
Differences between the CNS and PNS
Look at day 3 slides. One of the most important: cns damage is permanent, pns damage has the potential for recovery
What is the terminology difference between CNS and PNS for a bundle of nerves?
PNS: nerve CNS: tract
What is the terminology difference between CNS and PNS for a group of cell bodies?
PNS: ganglon CNS: nucleus
Afferent (sensory) nerves (and what system it is in)
In the PNS.  Go toward and into the CNS from sensory receptors.
Efferent (motor) nerves (and what system it is in)
From CNS to muscles and organs. Provokes movement from brain to neurons controlling muscles.
What is the role of the PNS?
To carry sensory information from the body to the CNS and bring back to the body motor commands.
2 divisions of the PNS
Somatic Nervous System and the Autonomic nervous system.
Somatic Nervous system
-interacts with external environment
-transmits somatosensory info to the CNS
-motor signals from the cns to skeletal muscles to control movement
Autonomic Nervous system
-regulates the body's internal environment
-transists sensory signals from glands/organs/smooth muscles to the cns
motor signals from cns to the glands/organs/smooth muscles
2 Nerves in the somatic nervous system
-Cranial nerves: connected directly to the brain
-Spinal Nerves: connected to the spinal cord
Cranial Nerves (pairs and function)
-12 pairs
-exit/enter directly from brain
-sensory, motor, or mixed (motor and sensory functions)
Spinal Nerves (pairs and function)
-31 left/right pairs
-mixed nerves
3 Cranial Nerves that only carry sensory information to the brain
1. Olfactory nerve (smell)
2. Optic nerve (sight)
3. Auditory (sound)
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