what is the overall functions of the Nervous system?
Is the master controling communicating system.
Its signaling device with body cellsis electrical impulseswhich are rapid and cause immediate repsonses
Which system control rapid electrical nerve impules?
A. Endocrine system
B. Nervouse system
B. Nervouse system - you got it.
The endocrine system organs produce hormones that are released into the blood
What are the 3 Functions of the Nervous System:
1. Sensory Input
3. Motor Output
What does the Sensory Input function do?
Monitors changes occuring both inside & outside the body.
* These changes are called stimuli
The info gathered is called sensory input
Integration function does?
Processes and interprets the sensory input.
then decides what should be done
Motor output function is?
the effect or causes actioned by the muscles is the motor output.
(ie. foot pressing the break pedal when you see a red light.)
What is the body parts of the central nervous system (CNS)
2. Spinal cord
What is the body of the Peripheral Nervous System?
2. Spinal Nerves
What is another name for Sensory division?
What does afferentmean?
To go towards
Afferent (or sensory) divison:
consists of nerve that send impulses tothe central nervous system from various parts of the body.
What is somatic?
(Remeber soma = body)
Are sensory fibers delivering impluses from the skin, skeletal musles and joints.
Efferent (motor) division does?
carries impulses FROMthe CNS to the effector organs, muscles and glands.
(These muscles bring about a motor response)
The Motor division has two subdivision called:
1. Somatic (body) Nervous system
2. Autonomic Nervous system
What does the Somatic (body) Nervous system do?
allows us to consciously, or voluntarily control our skeletal muscles
What does the autonomic nervous systemdo?
Regulates events that are automatic or involuntary.
(ie. smooth and cardiac muscles and glands)
What is another name for Autonomic Nervous system?
Involuntary nervous system
Which two subdivision fall under the Involuntary Nervous System (Autonomic Nervous system)
Sympathetic Nervous System does?
Is part of the autonomic nervous system
Speeding up the heartbeat and causes contraction of the blood vessels.
Regulates the function of the sweat glands and stimulates the secretion of glucose in the liver.
Sympathetic nervous system is activated especially under conditions of stress.
what does the Parasympathetic Nervous System do?
Sometimes called the rest and digest system Parasympathetic system conservesenergy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.
What are two classifications of cells located within the Nervous System
1. Supporting cells aka Neuroglia
What is Supporting cells aka Neuroglia?
this the the nerve glue
generally support, insulate and protect the delicate neurons
What is the fuction of the astrocytes cells?
they have swallen ends that cling to neurons, bracing them and anchoring them to their nutrient cappilary blood line
they protect neurons from harmful substances
help control the chemical environment in the brain by "mopping up" leaked potassium ions
What is the function of Microglia cells?
Phagocytes that monitor the health of neurons
dispose of debris, dead brain cells and bacteria
What is the function of Ependymal cells?
1. These cells line the central cavities of the brain and spinal cord
2. The beating of their cilia helps circulate cerebrospinal fluid
3. Forms protective cushion around CNS
What is the function of Oligodendrocytes cells?
1. Wrap their flat extensions (proceses) around the nerve fibers, producing fatty insulating coverings called myelin shealths
Form the myelin sheaths around nerve fibers that are found in PNS
What do Neurons do?
Are highly specialized cells that transmit messages from one part of the body to another
is the centre of the neuron
Picture of a motor neuron
convey incoming messages toward the cell body are called dendrites
Conduct nerve impulese away from the cell body
Protects and inculates the fibers
Increases transmission rate of nerve impulese
is a tight coil of wrapped membranes that encloses the axon.
Is the outter of the Schwan cells
Nodes of Ranvier are
The gaps formed between myelin sheath cells along the axons.
What is an interneuron?
Interneuron is a nerve cell that links motor and sensory neurons, and it transmits impulses between them.
What is a nerve?
one or more bundles of fibers forming part of a system that conveys impulses of sensation, motion, etc., between the brain or spinal cord and other parts of the body.
what is white matter?
consists of dense (thick) collections of myelinated fibers (tracts)
What is gray matter?
contains mostly UNmyelinated fibers and cell bodies
What is the tracts of the nerve?
bundle of nerve fibers running through the CNS
What are fasicles of the nerve?
a cluster or bundle of nerve fibers
what is the epineurium of the nerve?
the outer layer of the peripheral nerves contained in the human body.
what is the perineurium of the nerves?
It is a protective layer of tissue located around the nerves and internal organs
Picture of the Epineurium, Perineurium Endoneurium layers
What is the endoneurium layer of the nerve?
innermost layer of the perineurium
Define the term "reflex".
rapid, predictable, and involuntary responses to stimuli
Reflex Arcs: sensory receptors
Reacts to stimuli
REfelx Arcs: sensory neurons
to connect the sensory receptor and effector organ (the muscle or gland that has been stimulated)
Dorsal root ganglion
Is a nodule (knot) on a dorsal root that contains cell bodies of sensory neurons.
Is found in the afferent spinal nerves.
Has axon, which relays information into the CNS
Spinal cord cross section picture
Information from one neuron flows to another neuron across a synapse. The synapse contains a small gap separating neurons.
The synapse consists of:
1. A Presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles
2. A postsynaptic ending that contains receptor sites for neurotransmitters.
3. A synaptic cleft or space between the presynaptic and postsynaptic endings.
What is an interneuron?
A nerve cell that acts as a link between sensory neurons and motor neurons
what is a motor neuron?
Is a cell that directly or indirectly controls the contraction or relaxation of muscles
single synapse in the spinal cord that links the transfer of information from a sensory neuron to the proper motor neuron
What is a three neuron arc?
A three neuron reflex arc has to do with a crossed extensor reflex arc
(IE. When you step on a nail, your other leg extends to support your weight when you lift your other leg up off the nail) and a three neuron arc also has to do with the reflex that lifted your leg that stepped on the nail.
What are the four main regions of the brain?
1. Cerebral Hemisphere
4. Brain Stem
The cerebral hemisphere is one half of the cerebrum, the part of the brain that controls muscle functions and also controls speech, thought, emotions, reading, writing, and learning.
White matter, like the corpus callosum, allows different parts of the brain to communicate with each other.
The brain is divided into a right and left hemisphere, and the two halves are connected by the corpus callosum
Picture of the Corpus callosum
Four Lobes of the Brain
1. Frontal Lobe
2. Occipital lobe
3. Parietal Lobe
4. Temperal lobe
Concerned with reasoning, planning, parts of speech and movement (motor cortex), emotions, and problem-solving
PARIETAL LOBE Located behind the central sulcus.
Concerned with perception of stimuli such as touch, pressure, temperature and pain.
TEMPORAL LOBE (Located below the lateral fissure.)
Concerned with perception and recognition of auditory stimuli (hearing) and memory (hippocampus).
Deals with many aspects of vision.
seperate large regions of the brain
The cerebral hemisphere are seperated by single deep fissure called L______ F______?
Are elevated ridges of tissue on the cerebral hemisphere
are shallow groves on the cerebral hemisphere
seperates the frontal lobe and from the parietal lobe
Picture of brain
separates the parietal lobes and the occipital lobes in both hemispheres
Marks the separation of the temporal lobe from the frontal and parietal lobes
Speech, memory, logical, emotional, interpretations of sensation and voluntary movement are all functions of the cerebral cortext
which lobes of the brain are the locations of the sensory cortex
Where is the motor cortex in the brain?
Where is vision located in the brain?
Vision is located in the posterior (back part of brain) part of the occipital lobe
Which lobe is speech located in?
Frontal Lobe (BROCA is located in this lobe as well)
Where is skeletal mucsle movement located? (lobe wise)
Which lobe is taste located in?
Which lobe is muscle coordination located in?
which lobe is conscious thought in?
Location - Buried deep within the white matter of the cerebral hemisphere
Function - Body movement and coordination
Pic of Basal ganglia
Location - encloses the shallow third ventricalof the brain
function - is a relay station for sensory implulses UPWARD to sensory cortex
Location: under the Thalamus
Function: regulates body temperature, water balance and metabolism. alont with thirst, appetite sex, etc
Location - behind the third cerebral ventricle in the midline of the brain.
Secretion of the Hormone
Conversion of Nervous System Signals to Endocrine Signals
Causes Feeling of Sleepiness
Influences Sexual Development
Midbrain - small part of the brainstem
The midbrain controls visual and auditory systems as well as eye movement.
Location: Round structure that protudes below the mid brain.
Function: pons literally means bridge
serves as a communications and coordination center between the two hemispheres of the brain.
* Location: Most inferior (bottom) part of brain stem
* Function: controls heart rate
* Blood pressure
Location: Under the occiptal lobe of the cerebrum
function: controls skeletal muscle activity and controls our balance and equilibrium
When we drink alcohol our balance is effecte b/c it affects our cerebellum
lengths: 17 inches long (42cm)
where it starts: Foramen
Where is ENDS: Just below the ribs
Cauda equina is?
The collection of spinal nerves at the inferior end of the vertebral canal
where is the Cauda equina located?
in the lumbar region of the spine
What is the function of the spinal cord?
*Provides a TWO-WAY conduction path to and from the brain
* controls numerous reflexes
LO. # 28 - Cross section of spinal cord PICTURE:
anterior median fissure
posterior median sulcus
dorsal root ganglion
* Primarily sever head and neck
* There are 12 pairs of nerves that can be seen on the ventral (bottom) surface of the brain
Picture of Cranial nerve
There are 31 pairs of spinal nerves
Formed by ventral and dorsal roots of the spinal cord
Are located in/on the spine
What are MENINGES?
It is 3 connective tissue membranse covering and protecting the CNS
Is the outter most layer (leathery)
a fluid-filled space or potential space between the dura mater and the arachnoid
* middle meningeal layer
* Weblike (looks like cobwebs)
attached to the inner most membrane
Clings to the surface of the brain & spinal cord
Cerebrospinal fluid (CSF)
Is a watert broth similar to the make up of blood plasma.
The CSF is formed by blood
CSF around the brain and spinal cord forms a watery cushion the protects the nervous system from blows and trauma
are venous channels which drain the blood from the brain
are clusters of capillaries hanging from the roof in each of the brian ventricles
Absorption of the CSF into the blood streamtakes place in the superior sagittal sinus through structures called arachnoid villi
Blood- brain barrier
*Are composed of the least permeable capillaries in the body.
* Meaning very little passes through the blood brain barrier
what does permeable mean
allowing liquids or gas to pass through it
what does Blood- brain barrierlet pass through?
water and essential amino acids pass through these barriers
Blood- brain barrier block things like:
* urea, toxins, proteins, and most drugs
Blood- brain barrier is useless?
against fats, respiratory gases and fat soluable molecules.
This is why blood borne alcohol, nicotine, and anesthetics can affect the brain