Nervous System

Major function of the nervous system

Thinking, movement, Internal process of physiology

Somatic Nervous System

Controls voluntary skeletal muscle

Autonomic Nervous System

Controls involuntary effectors (smooth, cardiac muscles, and glands.

Central Nervous System

Made of the brain and spinal cord, responsible for integration of info and decision making

Peripheral Nervous System

Made of cranial and spinal nerves that connect to the CNS to the rest of the body

Peripheral Nervous (PNS)

nervous system that contain Sensory (Afferent) and Motor (Efferent) divisions

Multipolar neuron

Multi processes coming off soma, many dendrites, and one axon from their cell bodies in CNS (interneurons and motor neurons)

Bipolar neurons

Have two processes extending from the cell body (soma), a dendrite and an axon: found in some of the special senses, such as the eyes, nose, and ears

Unipolar neurons

Has only one process extending from the soma, and it soon splits into parts that function as one axon; the peripheral process has dendrites near a peripheral body part, & the central process runs into the CNS

Where can unipolar neurons be found

The cell bodies are found in ganglia outside the CNS; these are sensory neurons

Neuroglia

Glia cells “nerve cells” are cells that support neurons

Neuroglia functions

Fill space, structurally support, protect, and insulate neurons

Four types of CNS glia cells

Microglia, Oligodendrocytes, Ependymal cells, and Astrocytes

Microglia

Small cells that function as phagocytes for bacterial cells, and cellular debris, and produce scar tissue in sites of injury

Oligodendrocytes

For the myelin sheath around axons in the brain and spinal cord

Ependymal cells

Produce cerebrospinal fluid in central nervous system

Astrocytes

Provides structural support, regulation of nutrient and ion concentrations, and formation of blood-brain barrier, which protects brain tissue from chemical fluctuation and prevents entry of many substances

Schwann cells

The myelin producing neuroglia of the peripheral nervous system.

Satellite cells

Provide protective covering around cell bodies of neurons in PNS

Nerve

A _______ is a bundle of nerve fibers (axons) in the peripheral nervous system

Presynaptic

The neuron sending the impulse is the __________ neuron

Postsynaptic

The neuron receiving the impulses is the _______________ neuron

Neurotransmitter

Communication is accomplished by a chemical called a ___________________

Synaptic transmission

____________________ it the process by which the impulse in the presynaptic neuron is transmitted   across the synaptic cleft to the postsynaptic neuron.

Neuron, Neurotransmitter, cleft

When an impulse reaches the synaptic knob of an axon, synaptic ______________   release chemicals called ______________ into the synaptic _____________.

Step One of release of Neurotransmitter

Action potential passes along an axon and over the surface of it’s synaptic knob

Step two of release of Neurotransmitter

Then, the synaptic knob membrane become more permeable to calcium ions

Step three of release of Neurotransmitter

Then, In the presence of calcium ions, synaptic vesicles fuse to the synaptic knob membrane

Step four of release of Neurotransmitter

synaptic vesicles release thier neurotransmitter effects must be stopped

Neurotransmitter, Receptor

Action of ___________ depends on type of ______ in a specific synapse

**Sensory (afferent) neurons:**

conduct impulses from peripheral receptors to the CNS; usually unipolar, although some are bipolar.

**Interneurons (association or internuncial neurons):**

multipolar neurons lying within the CNS that form links between other neurons; the cell bodies of some interneurons aggregate in specialized masses called nuclei.

**Motor (efferent) neurons**

multipolar neurons that conduct impulses from the CNS to peripheral effectors (muscles or glands).

Cell body (soma)

The **_______________** contains mitochondria, lysosomes, a Golgi apparatus, chromatophilic substance

Dendites

_________ conduct impulses toward the cell body; they are short and branching, and they provide the receptive surface for communication with other neurons.

Axon

The **_____** conducts impulses away from the cell body; it arises from a thickening extending from the cell body, called the **axon** **hillock**

**Saltatory**

________ conduction occurs in myelinated axons. The myelin sheath insulates axons from ion movement across the cell membrane.

**Continuous**

__________ conduction occurs in unmyelinated axons. Conduct impulses sequentially over the entire length of their membrane.

Impulse conduction

An action potential at the trigger zone causes an electrical current to flow to adjacent regions of the axon’s membrane. spreads by a local current flowing down the fiber that stimulates the next region, and continues down the axon to the axon terminal.

thick, myelinated, motor

**Speed of impulse conduction ____**__**,**__ **_________**__**(un)myelinated**__ **____ axon conduct at 120 m/s**

thin, myelinated, sensory

**Speed of impulse conduction ____**__**,**__ **_________**__**(un)myelinated**__ **____ axon conduct at 0.5 m/s**

Excitatory

_________ neurotransmitters increase entry of Na+ ions into postsynaptic neuron, brings membrane closer to threshold, making action potential more likely

Inhibitory

____________ neurotransmitters increase flow of CL- ions to neuron or flow of K+ ions out of neuron, making charge inside neuron more negative, making action potential less likely

**Neurotransmitters**

**_______________** are the chemical messengers in a synapse, that convey an electrical impulse from a neuron to another cell

**preganglionic**

A **____________ neuron**, that leaves the CNS, and synapses with one or more neurons, which have cell bodies in an autonomic ganglion in the PNS.

**postganglionic**

•A **__________ neuron**, whose fiber (axon) leaves an autonomic ganglion, and innervates a visceral effector.

pain receptors (nociceptors)

**_________**_ communicates with other pain pathway sensory neurons using two main neurotransmitters: substance P and glutamate. These carry messages through the spinal cord and to the brain.

**Sympathetic division**

active in conditions of stress or emergency (fight or flight).

**Parasympathetic division**

active under normal, restful conditions (rest and digest).

temperature receptors

___________ sensation depends on two types of free nerve endings in the skin. those that respond to warmer temps are called warm receptors and those that respond to colder temps are cold receptors

proprioception

We need a continual “sense” of where we are in space and time. Known as ____________, are associated with skeletal muscle and provide information about body position

Baroreceptors

The blood vessels close to the heart contain stretch receptors called __________ that monitor blood pressure

Chemoreceptor

___________: receptor stimulated by the binding of certain chemicals

Photoreceptor

_____________: sensory receptor sensitive to light, rods and cones in the eyes

Cerebrum

Largest portion: is associated with higher mental function, and sensory and motor functions, stores info for memory, intelligence, and personality, and integrates info for reasoning

Diencephalon

Processes sensory input and controls many homeostatic processes, lies between the cerebra; hemispheres and above the midbrain

Cerebellum

Coordinates muscular activity, integrates sensory info about the position of body parts, coordinates skeletal muscle activity, maintains posture, and ensures that movement occurs in the desired manner

Brainstem

coordinates and regulates visceral activities, and connects different parts of the nervous system, consist of midbrain, pons, and medulla oblongata

Cutaneous

____________ senses: anterior parietal lobe

Visual Area

__________: posterior occipital lobe

Auditory area

posterior temporal lobe

Taste area

base of central sulcus and insula

smell area

Deep in temporal lobe

Frontal

Association areas of the ________ lobe control a number of higher intellectual processes (planning, problem solving)

Parietal

Association area of the ________ lobe function in understanding speech and choosing the proper words

Occipital

Association areas in _______ lobe help analyze visual patterns and combine visual images with other sensory info

Left

For most people, the ____ hemisphere is dominant for the language related activities of speech, writing, and reading, as well as complex intellectual function

Right

In some individuals, the _____ hemisphere as dominant, and others show equal dominance in both hemispheres/

Nondominant

The _____________ hemisphere specializes in nonverbal functions, such as body orientation in space, and controls emotions and intuitive thinking.

Corpus callosum

The nerve fibers of the ____________ connect two hemispheres; this allows the dominant hemispheres to control the motor cortex of the nondominant side.

Limbic system

The _______ system, in the area of the diencephalon, controls emotional experience and expressions such as feelings of fear anger, pleasure, and sorrow. Include cerebral cortex parts, deep masses of gray matter

Reticular formation or reticular activating system

A network of nerve fibers connecting small masses of gray matter throughout the brainstem, connect parts of the hypothalamus, basal nuclei, cerebellum, and cerebrum, filters incoming sensory impulses, decreases activity in this area results in sleep

Meninges

The brain and spinal cord are surrounded by 3 membranes called _________ that lie between the skull bones and vertebrae and the soft CNS tissue

Cerebrospinal Fluid (CSF)

_____________ circulates through ventricles and connecting passageways into the subarachnoid space, where it’s reabsorbed back into the blood, completely surrounds brain and spinal cord

Cerebrospinal

The central nervous system neuroglia has ependymal cells that produce ________ fluid.

Blood-brain- barrier

The formation of the _____________ occurs in astrocytes, and it protects brain tissue from chemical fluctuation and prevents entry of many substances

Olfactory

First cranial nerve, sensory type, Functions: sensory fibers conduct impulses associated with the sense of smell

Optic

2nd cranial nerve, sensory type, Function: sensory fibers conduct impulses with the sense of vision

Oculomotor

3rd cranial nerve, primarily motor type, Function: motor fibers conduct impulses to muscles that raise eyelids, move eyes, adjust the amount of light entering the eyes, and focus lenses

Trochlear

4th cranial nerve, primarily motor, Function: motor fibers conduct impulses to muscles that move eyes, some sensory fibers conduct impulses associated with the condition of muscles

Trigeminal

5th cranial nerve that consist of 3 different types of division

Ophthalmic division

Apart of 5th cranial nerve (trigeminal), Function: sensory fibers conduct impulses from the surface of the eyes, tear glands, scalp, forehead, and upper eyelids

Maxillary division

Apart of 5th cranial nerve (trigeminal), Function: sensory fibers conduct impulses from the upper teeth, upper gum, upper lip, lining of palate, and skin on face

Mandibular division

Apart of 5th cranial nerve (trigeminal), Function: sensory fibers conduct impulses from the skin of jaw, lower teeth, lower gum, and lower lip. Motor fibers conduct impulses to muscles of mastication

Abducens

6th cranial nerve, primarily motor. Function: motor fibers conduct impulses to muscles that move the eyes. Some sensory fibers conduct impulses associated with the condition of muscles

Facial

7th cranial nerve, mixed type. Function: sensory fibers conduct impulses associated with taste receptors of the anterior tongue. Motor fiber conduct impulses to muscles of facial expression, tear glands, and salivary gland

Vestibulocochlear (vestibular branch)

8th cranial nerves, sensory type. Function: sensory fibers conduct impulses associated with the sense of equilibrium

Vestibulocochlear (Cochlear branch)

8th cranial nerves, sensory type. Function: sensory fibers conduct impulses associated with the sense of hearing

Glossopharyngeal

9th cranial nerve, mixed type. Function: sensory fibers conduct impulses from the pharynx, tonsils, posterior tongue, and carotid arteries

Vagus

10th cranial nerve, mixed type. Function: somatic motor fibers conduct impulses to muscles associated with speech and swallowing: autonomic motor fibers conduct impulses to heart, smooth muscle, and glands in thorax and abdomen, sensory fibers conduct impulses from pharynx, larynx, esophagus, & viscera of thorax and abdomen

Accessory (cranial branch)

11th cranial nerve, primarily motor. Function: motor fibers conduct impulses from pharynx, larynx, esophagus, and viscera of the thorax

Accessory (spinal branch)

11th cranial nerve, primarily motor, Function: motor fibers conduct impulses to muscles of the neck and back

Hypoglossal

12th cranial nerve, primarily motor, Function: motor fibers conduct impulses to muscles that move the tongue

Dorsal root ganglion

Each dorsal root contains a ____________________, which houses the cell bodies of sensory neurons entering the spinal cord

Ventral root, Dorsal root

_____ root and a _______ root unite to form a spinal nerve, which extends out of the vertebral canal through the intervertebral foramen

What are the parts of reflex arc

Receptor, sensory neuron, interneuron, motor neuron, and effector

Receptor

_________ end of a dendrite or a specialized receptor cell in a sensory organ. Function: senses specific type of internal or external change

Sensory neuron

______________: Dendrite, cell body, and axon of a sensory neuron. Function: Carries info from receptor into brain or spinal cord

Interneuron

__________: Dendrite, cell body, and axon of a neuron within the brain or spinal cord. Function: carries info from sensory neuron to motor neuron