Nervous System - 11.2 Flashcards
What is the central nervous system?
Structural and functional Centre of the entire nervous system
Site of neural integration and processing - receives information from senses - evaluates information - initiates outgoing response
What can damage to the nervous system affect?
Temperament, motor control, and homeostasis
What is Bovine Spongiform encephalopathy (BSE)?
Disease that causes sponge like holes in the brain - often called “mad cow disease”
Initially causes nervousness and over sensitivity to touch
What causes BSE?
an infectious protein
What are the two main types of tissue that the nervous system is composed of?
Grey matter and white matter
Describe grey matter.
Grey matter is grey - contains mostly cell bodies, dendrites, and short, unmyelinated axons (nerve fibers)
Contains many spinal neurons
Where is grey matter found?
Found around the outside areas of the brain - Forms H shape core of spinal cord
Describe white matter?
White matter is white - contains myelinated axons that run together in tracts
Where is white matter found?
Forms in the inner region of some areas of the brain - outer area of the spinal cord
What is the spinal cord?
The spinal cord is a nerve tissue - extends out of the skull from the brain - and downward through a canal within the backbone
Why is the spinal cord important?
It is the vital communication center between the brain and PNS
Within spinal cord - sensory neurons carry messages to the brain for interpretation
- Motor neurons relay messages from the brain to effectors
Primary reflex center - coordinating rapid incoming and outgoing neural information
What are the delicate tissues of the spinal cord protected by?
Cerebrospinal fluid
Soft tissue layers
Spinal column ( a series of backbone - vertebrae)
What happens if you injure the spinal column?
You can damage the spinal cord - resulting in paralysis
Greek philosopher Aristotle knew that directly touching the brain did not cause any sensations to owner, what did he conclude?
He concluded that the heart must be in control of human intelligence - sensations - and body functions
What is the Centre for intelligence, consciousness, and emotion?
The Brain!
What are the three regions of the brain?
The hindbrain, mid brain, and forebrain
Describe the brain.
Brain is fragile - has gelatin like consistency
skulls form bony, protective layer around brain
Meninges
What are meninges?
Three layers of tough, elastic tissue within spinal cord and brain - directly encloses the brain and spinal cord
What is the cerebellum and describe it.
It is a walnut shaped structure
Located below and largely behind cerebrum
Involved in unconscious coordination ( reflexes and body movements)
- Voluntary motor skills (hitting tennis ball, playing piano)
Receives information from specialized sensors (proprioceptors - located within skeletal muscles and joints)
What is the medulla oblongata and describe it.
Sits at base of the brain stem - connects brain with spinal cord
Contains centers that control autonomic, involuntary movements (heart rate, breathing, dilation and constriction of blood vessels)
What is the pons and describe it?
It is found above and in front of the medulla oblongata
Serves as a relay center between - neurons of the right and left halves of the cerebrum, cerebellum, and rest of brain
What is the Midbrain and describe it?
It is found above the pons
Relays visual and auditory information - between areas of the forebrain and hindbrain
Plays important role in eye movement - control of skeletal muscles
What is the Thalamus and what does it do?
It sits at the base of the forebrain
Consists of neurons that provide connections between various parts of the brain
- between forebrain and hindbrain
- sensory system (not smell) and cerebellum
Often referred to as “the great relay station of the brain”
What is the Hypothalamus and what does it do?
It helps regulate the bodies internal environment and behavior
Contains neurons that control blood pressure, heart rate, body temperature, basic drives (thirst, hunger), emotions (fear, rage)
Damage to it - person can display unusual, violent behavior
Major link between nervous and endocrine systems
Coordinates the actions of the pituitary gland - regulating and producing the release of certain hormones
What is the cerebrum and what does it do?
Largest part of the brain
Divided into right and left cerebral hemispheres (contains the intellect, memory, conscious, and language centres)
It interprets and controls the response to sensory information
What are the meninges and what are its three layers?
Meninges are a three layer, elastic protective tissue that protects the central nervous system
Dura mater, arachnoid layer, and pia mater
What causes meningitis and how can it be diagnosed?
Meningitis is caused by a bacterial or viral infection - it can be diagnosed by testing cerebrospinal fluid
How do the meninges protect the CNS?
Act as shock absorbers - prevent the direct circulation of blood through the cells of the brain and spinal cord
What is the separation of blood and the CNS called?
The blood brain barrier.
What happens if oxygen supply to the brain is disrupted?
stroke - when arteries that supply the brain with blood are blocked
What are the blood capillaries that lead to the brain made of?
Tighly fused Epilethial cells
What is the total amount of cerebrospinal fluid in an adult and how much is produced per day?
150 ml - in adult
500ml - produced per day
Where is the cerebrospinal fluid found and what does it transport?
In the ventricles within the brain
They transport: hormones, nutrients, and white blood cells
What two layers of the meninges is cerebrospinal fluid found?
Between arachnoid layer and pia mater.
What does each half of the cerebrum consist of?
Internal mass of white matter
Thin outer layer made of grey matter - cerebral cortex
What is the cerebral cortex responsible for?
language, memory, personality, vision, conscious thought - any other activities involved with thinking or feeling.
Describe the structure of the cerebral cortex?
About 5mm thick - highly convoluted (allows to fit high concentration of grey matter)
Convolution and fissures - increase surface area
What are the left and right halves of the cerebrum called and what links them?
Left and right Hemispheres
Linked by white matter - corpus collosum (sends messages from one hemisphere to other - telling other what the other is doing)
What is the right brain or right cerebral hemisphere associated with?
holistic and intuitive thinking, visual spatial skills, and artistic abilities
What is the left brain or left cerebral hemisphere associated with?
segmental, sequential, and logical ways of thinking - mathematical and linguistic skills
Four pairs of lobes that each pair of the cerebral cortex is divided into?
Frontal Lobe, Parietal Lobe, Occipital Lobe, and Temporal Lobe
Describe the occipital lobe.
Receives and analyzes visual information - needed for recognition of what is being seen
Damage to occipital lobes - person can see object but not recognize them
Describe the temporal lobe.
Share in the process of visual information - main function is auditory reception
Linked to understanding speech - retrieving visual and verbal memories
Describe the parietal lobe.
Receive and processes sensory information from the skin
Portion of parietal lobe in a particular area of the body - related to the importance of sensory information for this part of the body
Helps process information about bodies position and orientation
Describe the frontal lobe.
Integrates information from other parts of the brain - controls reasoning, critical thinking, memory and personality
Broca’s area - involved with language use
Contains motor areas that control voluntary motor movements
Proportion of frontal lobe is dedicated to particular part of body - correlates with degree of complexity movement that body structure can make
How is it possible that each side of the brain controls muscles on the opposite side of the body.
The nerves leading from right to left in the frontal lobe cross over in the brainstem
What are two important areas on the left side of the cerebral cortex involved with speech?
Broca’s area - coordinates muscles for speaking - makes thoughts words (damage to it can affect ability to speak - can still understand words though)
Wernicke’s area - stores information involved in language comprehension (if damaged you can utter words - words will make little sense though)
Who is Phineas George?
Explosion drove metal bar through frontal lobe - he experienced a personality change
What did Wilder Penfield do?
Canadian Nobel Prize recipient - He operated on people with epilepsy - applied electrical currents to surface of brain to find the problem areas
What is PET and what does it do?
Positron Emission Tomography
Person receives injection of radioactively labelled glucose - scanner monitors glucose consumption in the brain
Can be used to diagnose Alzheimer’s (detoriation of brain that leads to memory loss, confusion, lack of conscious movements).
What is MRI and how does it work?
Magnetic renosance imaging
Magnet is put on persons head - changes in direction of the magnetic field - induce hydrogen atoms in the brain to emit radio signals
These images signals can be detected, translated, and displayed as structural and functional images.
