Nervous and Endocrine System

Question 1

Central Nervous System

Answer 1

includes spinal cord and brain. In the “center” of the body

Question 2

Peripheral Nervous System:

Answer 2

includes autonomic and somatic nervous systems

Question 3

Somatic Nervous System

Answer 3

connects to skeletal muscle

Question 4

Autonomic Nervous System

Answer 4

connects to
smooth (involuntary) muscles

Question 5

Autonomic Nervous System is further divided into the…

Answer 5

Sympathetic
Nervous System (usually causes effects associated with emergency situations) and the Parasympathetic
Nervous System (promotes activities associated with a normal state).

Question 6

SENSORY NEURON:

Answer 6

afferent neuron - takes a message from a sense organ to CNS. has long
dendrite and short axon

Question 7

MOTOR NEURON:

Answer 7

efferent neuron- takes
message away from CNS to a muscle fiber or gland. Short dendrites, long axon.

Question 8

INTERNEURON:

Answer 8

association neuron or
connector neuron): completely contained within CNS. Conveys messages between parts of the system. Dendrites, and axons, may be long or short.

Question 9

Nerve Conduction is…

Answer 9

an ELECTROCHEMICAL CHANGE that moves in one direction along the length of a nerve fiber. It is electrochemical because it involves changes in voltage as well as in the concentrations of certain ions.

Question 10

Resting Potential

Answer 10

When not conducting impulses, there is a voltage difference across the
membrane of the axon of about -60 mV. The negative charge on the
inside of the axon is due to the presence of large negative ions. There are more sodium ions on the outside of the axon compared to the inside of the axon, and more potassium ions on the inside compared to the outside.

Question 11

ACTION POTENTIAL:

Answer 11

POTENTIAL: if a nerve is stimulated by electric shock, pH change, or mechanical stimulation, a nerve impulse is generated, and a change in potential can be seen.

Question 12

RECOVERY PHASE:

Answer 12

between transmissions, K+ ions are returned to the inside of the axon, Na+ to the outside. This is done actively

Question 13

The speed of nerve impulses is?

Answer 13

quite rapid. due to the structure of the nerves. Specifically, the MYELIN SHEATH of most nerve fibers (this sheath is formed by tightly packed spirals of the cell membrane of Schwann cells) and the interruptions or gaps of the sheath called the NODES OF RANVIER.

Question 14

Myelinated or non-myelinated neurons transmit info faster?

Answer 14

Myelinated because impulse can “skip” over the sheath where as non-myelinated has to go step by step each time

Question 15

Synapse:

Answer 15

the region between end of an axon and the cell body or dendrite to which it is attached.

Question 16

Synaptic Endings:

Answer 16

swollen terminal knobs on the ends of axon terminal branches.

Question 17

Presynaptic Membrane:

Answer 17

the membrane of the axon synaptic
ending.

Question 18

Postsynaptic Membrane:

Answer 18

the membrane of the next neuron just beyond the axon’s synaptic membrane.

Question 19

Synaptic Cleft:

Answer 19

the space between the presynaptic and the postsynaptic membranes

Question 20

Neurotransmitter Substances (neurotransmitters):

Answer 20

chemicals that transmit the nerve impulses across a synaptic cleft.

Question 21

Synaptic Vesicles:

Answer 21

contain the neurotransmitters. Contained near the surface of synaptic endings.

Question 22

Transmission across a synapse is — because only the – have synaptic vesicles that
are able to release – to affect the potential of the next neurons.

Answer 22

one-way, ends of axons, neurotransmitters

Question 23

Sequence of events for synapes

Answer 23

• neurotransmitters take nerve impulses across synapses.
  Neurotransmiters are small molecules. They can be single amino
  acids, short chains of amino acids, or derivatives of protein.
• proper brain and nervous system function depends on the proper
  balance of excitatory and inhibitory synaptic transmitters.
  Excitatory transmitters: include ACETYLCHOLINE (ACh),
  ADRENALIN (epinephrine), NORADRENALIN (norepinephrine),
  SEROTONIN (derived from the amino acid tryptophan), and
  DOPAMINE.
• A single neuron may receive
  information from thousands of
  neighbouring neuron through
  thousands of synapse. Some of the
  messages are excitatory (i.e. they tell
  the neuron to “fire”) while others may
  be inhibitory (i.e. they tell the neuron
  not to fire).
• Whether or not a neuron “fires” off an action potential at any particular
  instant depends on its ability to
  integrate these multiple positive and
  negative inputs.

Question 24

Reflexes

Answer 24

automatic, involuntary responses to changes occurring inside or outside the body. Can
involve the brain (e.g. blinking) or not involve brain (e.g. withdraw hand from hot stove).

Question 25

Reflex arc

Answer 25

main functional unit of the nervous system. It allows us to react to internal and external stimuli.

Question 26

Path of a simple Reflex Arc:

Answer 26

Receptor (e.g. in skin) - generates a nerve impulse 2. Sensory Neuron - takes message to CNS. Impulses move along dendrite, proceed to cell body (in dorsal root ganglia) and then go from cell body to axon in gray matter of cord. 3. Interneuron - passes message to motor neuron 4. Motor neuron - takes message away from CNS to axon of spinal nerve 5. Effector - receives nerve impulses and reacts: glands secrete and muscles contract

Question 27

AUTONOMIC NERVOUS SYSTEM

Answer 27

made of motor neurons that control the internal organs AUTOMATICALLY (usually unconsciously).

Question 28

SYMPATHETIC NERVOUS SYSTEM:

Answer 28

is especially important during EMERGENCY SITUATIONS and is associated with "FIGHT OR FLIGHT" reaction.

Question 29

PARASYMPATHETIC NERVOUS SYSTEM

Answer 29

The parasympathetic System promotes all the internal responses associated with a RELAXED state. For example: * causes the pupils to contract * energy diverted for digestion of food * heart rate slows

Question 30

CENTRAL NERVOUS SYSTEM

Answer 30

consists of the BRAIN and SPINAL CORD. The CNS lies in the mid-line of the body and is the place where sensory information is received and motor control is initiated.

Question 31

Spinal Cord:

Answer 31

contains central canal filled with cerebrospinal fluid and the highway of neurons

Question 32

GRAY MATTER

Answer 32

(inner layer) containing cell bodies of neurons and short fibers. Looks kind of like the a butterfly with open wings. * in grey matter, dorsal cell bodies function primarily in receiving sensory information, and ventral cell bodies send along primarily motor information.

Question 33

WHITE MATTER

Answer 33

(outer layer) containing long fibers of interneurons that run together in bundles called tracts that connect the cord to the brain. * within white matter, ascending tracts take information to the brain, descending tracts in the ventral part carry information down from the brain.

Question 34

MEDULLA OBLONGATA

Answer 34

Lies closest to spinal cord. Controls heart rate, breathing, blood pressure, reflex reactions like coughing, sneezing, vomiting, hiccoughing, swallowing. An "ancient" part of brain. The Pons also participates in some of these activities, having ganglia that regulate the breathing centers in the medulla, for example.

Question 35

THALAMUS

Answer 35

receives sensory information from all parts of the body and channels them to the cerebrum. It is the last portion of the brain for sensory input before the cerebrum. Serves as a CENTRAL RELAY STATION for sensory impulses coming up spinal cord and other parts of brain to the cerebrum. Receives all sensory impulses (except for smell) and sends them to appropriate regions of the cortex for interpretation.

Question 36

CEREBELLUM

Answer 36

controls balance and complex muscular movement. It is the second largest portion of the brain. Butterfly-shaped. Functions in muscle coordination and makes sure skeletal muscles work together smoothly. Responsible for maintaining normal muscle tone, posture, balance. It receives sensory information from the inner ear (which senses balance).

Question 37

HYPOTHALAMUS

Answer 37

one of the most important sites for the regulation of homeostasis. It maintains internal environment, contains centers for hunger, sleep, thirst, body temperature, water balance, blood pressure.

Question 38

PITUITARY GLAND

Answer 38

(serves as a link between the nervous system and the endocrine systems).

Question 39

CORPUS CALLOSUM

Answer 39

(Y)- horizontal connecting piece between the two hemispheres of the brain. Transmits information between the two cerebral hemispheres. It has been noted that severing the corpus callosum can control severe epilepsy (which is thought to be caused by a disturbance of the normal communication between the RAS and the cortex), but also means the two halves of brain don't communicate with each other normally and will function separately. Each half has its own memories and “style” of thinking. Sometimes you’ll hear this discussed as “right brain” versus “left brain” thinking.

Question 40

CEREBRUM

Answer 40

largest, most prominent, most highly developed portion of the brain. * Consciousness resides only in this part of the brain.

Question 41

FRONTAL

Answer 41

movement, higher intellectual processes (e.g. problem solving, concentration, planning, judging the consequences of behavior, moving your tongue and mouth to speak (left side only).

Question 42

PARIETAL

Answer 42

sensations e.g. touch, temperature, pressure, pain. Understanding speech, using words

Question 43

TEMPORAL

Answer 43

hearing, smelling, interpretation of experiences, memory of visual scenes, music, and complex sensory patterns.

Question 44

OCCIPITAL

Answer 44

vision, combining visual experiences with other sensory experiences.

Question 45

5 ways a drug can act with synapses

Answer 45

1. drug stimulates release of neurotransmitter. 2. drug blocks release of neurotransmitter 3. drug combines with neurotransmitter preventing its breakdown 4. drug mimics neurotransmitter 5. drug blocks receptor so neurotransmitter can't be received * These drugs can be as common as the caffeine found in coffee, theophylline in tea (both block the action of adenosine, a chemical that inhibits the release of neurotransmitters). * Nicotine enhances the action of acetylcholine. Some drugs (e.g. Thorazine) also affect cognitive or thinking processes. Mood-altering drugs particularly affect the RAS. * Drugs either promote or decrease the action of neurotransmitters, either stimulating or inhibiting the action of excitatory transmitters or inhibitory transmitters. Stimulants either enhance excitatory transmitters or block the action of inhibitory transmitters. Depressants either enhance the action of an inhibitory transmitter or block the action of an excitatory transmitter.