the ___ governs people's consciousness, their personalities, how they learn, and their ability to memorize
nervous system
Working with the endocrine system, the nervous system regulates and maintains
homeostasis.
The nervous system is anatomically divided into two parts:
Center and Peripheral
The ______ is comprised of the brain and spinal cord. It is where information processing and control occurs.
central nervous system
The _____ is comprised of the nerves associated with the CNS. It connects all nerves of the body to the CNS.
peripheral nervous system
There are two types of fibers in the PNS:
afferent and efferent
_____ transmit impulses from organs and tissues of the body to the CNS
afferent fibers
____ transmit impulses from the CNS to the organs and tissues of the body.
efferent fibers
The PNS is further divided into the
somatic and autonomic nervous systems
The ______ primarily controls voluntary activities such as walking and riding a bicycle. Thus, this system sends information to the CNS and motor nerve fibers that are attached to skeletal muscle.
somatic nervous system
The ____ is responsible for activities that are non-voluntary and under unconscious control.
autonomic nervous system
Because the autonomic nervous system controls glands and the smooth muscles of internal organs, it governs activities ranging from heart rate to ___ and ___
breathing and digestion.
the autonomic nervous system is further divided into the
Sympathetic nervous system and parasympathetic nervous system
The ___ nervous system focuses on emergency situations by preparing the body for fight or flight.
sympathetic
The ____ nervous system controls involuntarily processes unrelated to emergencies. This system deals with "rest or digest" activities.
parasympathetic
TEST TIP: The first letter in the parasympathetic and sympathetic nervous system can be used to tell them apart:
Sympathetic = stress Parasympathetic = peace
Sensory:
Information is gathered (both internally and externally) and carried to the CNS. The senses gather the information that the sensory nervous system transmits.
Integrative:
The integrative nervous system is where the CNS process and interprets information received from the sensory nerves.
Motor:
Motor nerves convey information that is processed by the CNS to muscles and glands.
The ____ is a mass of tissue that is made of billions of nerve cells called neurons. This complex organ controls a wide range of processes and integrates information received from the five senses.
brain
Protected by the skull, the brain consists of four cavities called
ventricles
the brain cavities (ventricles) are filled with _____, which surrounds the CNS. This fluid serves many purposes such as protecting the brain from physical shocks and removing wastes from the neural tissue in the brain.
cerebrospinal fluid (CSF)
*TEST TIPS* The lobes (of the brain) are named after the bones of the skull that protect each lobe. For example, the frontal bone protects the frontal lobe.
look at pic
the brain is divided into three regions
cerebellum, brainstem, cerebrum
This is found beneath the cerebrum and behind the brainstem. It helps coordinate body movements, posture, and balance.
Cerebellum
This is found between the thalamus and the spinal cord. It is the lowest part of the brain that connects the brain with the spinal cord.
Brainstem
Unconscious functions like breathing, heart rate, and blood pressure are controlled by the
brainstem
This part of the brain is the largest and part of the forebrain
Cerebrum
The ____ controls higher-order functions such as interpreting touch, speech and language, reasoning, emotions, and fine motor control.
cerebrum
The ___ is grey (or gray) matter that surrounds the entire cerebrum. It is divided into a left and right hemisphere
cerebral cortex
The ridges of the cerebral cortex are called
gyri
the grooves of the cerebral cortex are called
sulci
The very large grooves of the cerebral cortex are called
fissures
The cerebral cortex is divided into four lobes: the
frontal, parietal, temporal, and occipital lobe.
The ____ is the most complex part of the brain, and each lobe has specific functions
cerebral cortex
frontal lobe function
Processes high-level cognitive skills, reasoning, concentration, motor skills, language, and functions as a control center for emotions
parietal lobe function
Integration site for visual perception and sensory information such as touch, pain, and pressure
temporal lobe function
Organizes sounds and processes language that is heard. Helps form memories, speech perception, and language skills.
occipital lobe function
Interprets visual stimuli and information
Grey mater is a type of neural tissue that contains three types of neurons, which are nerve cells that make up the nervous system:
sensory neurons, motor neurons, and interneurons
Afferent nerve cells that send information toward the CNS. This information is what is sensed, using the five senses, from the external environment
sensory neurons
Efferent nerve cells that carry impulses away from the CNS to the effectors, which are typically tissues and muscles of the body.
motor neurons
Nerve cells that act as a bridge between motor and sensory neurons in the CNS. These neurons help form neural circuits, which helps neurons communicate with each other.
interneurons
_____ is found in the spinal cord and surrounds the grey matter. It contains bundles of interneurons.
White matter
Another part of the forebrain includes the ______, which controls emotions and memory. As shown in the image, this system is found right beneath the cerebral cortex and sits above the brainstem.
limbic system
Four major structures of the brain comprise the limbic system:
hypothalamus, amygdala, thalamus, hippocampus
Found below the thalamus, this structure plays a role in regulating the autonomic nervous system. It is primarily concerned with homeostasis and regulates various activities such as hunger, anger, and the response to pain.
Hypothalamus
The ____ works with the pituitary gland from the endocrine system. This gland uses hormones, or chemical messengers, to generate responses in the body.
hypothalamus
Recognized as the aggression center, areas of this region produces feelings such as anger, violence, fear, and anxiety
Amygdala
Different sensory inputs come through the nerves and end at the ____, which directs this information to various parts of the cerebral cortex.
Thalamus
The sense of ____ is the only sense that bypasses the thalamus.
smell
Information related to ___ is also processed by the thalamus.
movement
Helps convert short-term memory to long-term memory. If this structure is destroyed, new memories cannot be formed but old memories are retained.
Hippocampus
__________ is a condition that includes destruction of the amygdala. This means a person will present with erratic emotional behavior symptoms like hypersexuality, compulsive eating, and putting objects in the mouth.
Kluver-Bucy syndrome
the nervous system is comprised of specialized cells called
neurons
A large network of neurons work together to
quickly send and receive messages throughout the body
A neuron's structure is designed to transmit electric signals before they are transmitted as
chemical signals to a target cell
The following three basic parts make up a single nerve cell:
cell body, dendrites, and axons
This is the main part of the neuron that contains the nucleus of the nerve cell. Also called the soma, other organelles are also found in the cell body.
Cell body
These are appendages attached to the cell body that receive signals from other neurons
Dendrites
This is the long structure attached to the cell body. It conducts and transmits information to other cells.
Axon
Branches at the end of the axon form _____. These branches facilitate communication between neurons and target cells.
axon terminals
Neuroglial cells do not conduct nerve impulses like neurons. Rather, they provide support and ____
protect neurons
Astrocytes, oligodendrocytes, microglial cell, and ependymal cells are the four major types of _____ in the CNS. Schwann and satellite cells are in the PNS.
neuroglial cells
The _____ is a protein and lipid structure produced by a type of glial cell called a Schwann cell
myelin sheath
The myelin sheath functions like a blanket that provides a layer of insulation around the axon of a neuron, increasing the speed of
electrical signal transmission
Regularly spaced gaps called _____ are found between the myelinated sheaths. Electric signals jump from one node to the next, thereby increasing the speed of signal transmission.
nodes of Ranvier
Several diseases cause degeneration of the myelin sheath, or ___. One example is multiple sclerosis
demyelination
When demyelination occurs, it can lead to severe neurological problems like
motor and cognitive function.
Demyelination ____ the speed at which neural impulses are transmitted along the axon.
reduces
The electric signals neurons transmit are called
neural impulses
Neurons must be excited to create a ____. A stimulus triggers excitation
nerve impulse
At the resting state, the inside of the neuron is more negatively charged, while the outside of the neuron is more positively charged. This difference in electrical charge because of potassium and sodium ions establishes the
resting potential.
As a person ages, the rate of _____, or ability for the brain to form neural connections through synapses, decreases.
neuroplasticity
Neuroplasticity is important because it helps the brain adapt to new stimulation, damage, or
changes in the environment.
During the _____, a reverse in electrical charge occurs across the membrane of a neuron in its resting state. As shown in the following image, this happens when a neuron receives a neural impulse by way of a stimulus or a chemical signal from another neuron. The inside of the neuron becomes more positively charged, while the outside of the neuron becomes more negatively charged. This reverse in charge travels down the axon as an electric current.
action potential
Steps of an electrical synapse
1. Once the action potential reaches the terminal bulbs of the axon terminal, the synaptic transmission process begins. The sequential numbers in the image outline the steps of synaptic transmission. The details of each numbered step are outlined below:An action potential travels down the axon and reaches the terminal branches of the axon. Voltage gated sodium gates open, causing sodium to enter the axon terminal bulb.2. Voltage gated Ca2+ channels open at the same time.3. Calcium ions move into the axon terminal bulb of the presynaptic neuron.4. Calcium ions bind with proteins on synaptic vesicles that carry chemical messages called neurotransmitters.5. This binding causes the vesicles to contract and move to the presynaptic membrane.6. Neurotransmitters are released from the vesicles via exocytosis and diffuse across the synaptic cleft.7. Neurotransmitters bind with receptors on the postsynaptic membrane of a neuron, gland, or muscle.8. Depending on what the postsynaptic target cell is, the following responses will happen:- Axon to dendrite: Action potential travels to next neuron.- Axon and muscle cell: Muscle contraction.- Axon and gland: Hormones released from gland.