Nervous System Anatomy and Physiology

hypothalamus

lower portion of diencephalon which acts as an autonomic center regulating metabolism, heart rate, blood pressure, thirst, hunger, energy level, and body temperature

epithalamus

upper portion of diencephalon that regulates hormones secreted by the pineal gland. The pineal gland produces melatonin, a serotonin derived hormone which modulates sleep patterns

cerebellum

a major feature of the hindbrain responsible for body movements and balance

cerebrum

the principal and most anterior part of the brain in vertebrates, located in the front area of the skull and consisting of two hemispheres, left and right, separated by a fissure

midbrain

relays sensory and motor impulses; serves important functions in motor movement, particularly movements of the eye, and in auditory and visual processing.

pons

part of the brain stem, assists with regulation of breathing

medulla oblongata

part of brain stem, regulates heart rate, blood pressure, and breathing, and controls the reflexes of coughing, sneezing, and vomiting

pituitary gland

a pea-sized structure located at the base of the brain, just below the hypothalamus, to which it is attached via nerve fibers. It is part of the endocrine system and produces critical hormones, which are chemical substances that control various bodily functions

thalamus

middle portion of diencephalon which relays sensory impulses up to the sensory cortex (aka the cerebrum); regulates sleep and consciousness

spinal cord

a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column

striatum

structure lying at the base of the forebrain which is a critical component of the motor and reward systems. Coordinates decision-making, motivation, and reinforcement.

corpus callosum

a thick band of nerve fibers that divides the cerebral cortex lobes into left and right hemispheres and acts as the connection between the two.

meninges

three layers of protective tissue between the brain and skull

frontal lobe

cerebrum lobe responsible for memory, intelligence, behavior, emotions, motor function, and smell

occipital lobe

cerebrum lobe responsible for vision and speech

parietal lobe

lobe responsible for somatic sensations (pain, touch, temperature perception), and speech

temporal lobe

lobe responsible for hearing, smell, memory, speech, and emotion

brain stem

Portion of brain that contains the pons, medulla oblongata, and the beginning of the spinal cord, controls the flow of messages between the brain and the rest of the body, and it also controls basic body functions

Broca's area

area on left frontal lobe responsible for tongue and lip movements

primary motor cortex

area in frontal lobe responsible for sending impulses to muscles

primary somatic sensory cortex

area in parietal lobe responsible for interpreting sensory impulses from the body

dura mater

outermost meninges layer

arachnoid mater

middle meninges layer

pia mater

inner meninges layer

sensory input

also known as the afferent pathway; the gathering information about changes in the environment

integration

process of interpreting sensory input and deciding motor output

motor output

also known as the efferent pathway; the response sent from the CNS to the rest of the body

CNS

composed of brain and spinal cord

PNS

composed of all other nerves and sensory receptors

autonomic NS

involuntary control of cardiac adn smooth muscles

Somatic NS

voluntary control of skeletal muscles

parasympathetic

part of autonomic N.S. responsible for involuntary daily functions

sympathetic NS

part of the autonomic N.S. responsible for response to potential danger

Schwann cells

neuroglia that produce myelin sheaths around nerve fibers in the PNS

dendrites

conduct impulses toward the cell body of a neuron

axons

conduct impulses away from the cell body of a neuron

myelin sheath

insulating material on axon fibers that increase the rate of impulse transmission

neurotransmitter

a chemical messanger that sends a message from the axon terminals to a muscle or nearby neuron

synaptic cleft

a gap between axon terminals and nearby muscles or neurons

action potential

another name for a nerve impulse

depolarization

the inflow of sodium ions resulting in a more positive environment inside the neuron and the propagation of an action potential.

repolarization

the outflow of potassium ions resulting in the return of a more positive environment outside the neuron.

refractory period

time between the start of an action potential and repolarization

fissure

a deep grove in the brain

Meningitis

inflammation of the meninges causing pin-point rashes, fever, photophobia, etc.

Streptococcus pneumonia

The cause of meningitis

Leprosy

Disease characterized by skin lesions and sensory loss

Polio

A flu-like disease that can result in paralysis, inflicts children younger than 6

Botox

The use of toxins to block nerve signals from the brain to targeted muscle area

Cerebral palsy

the inability to control muscles due to brain damage or brain malformation

Multiple sclerosis

an autoimmune disease that results from break down to myelin sheaths, results in various symptoms that make it difficult to diagnosis

Epilepsy

disease characterized by seizures and cause unknown

seizure

disorganized and sudden electrical activity in the brain

Parkinson's disease

issue with dopamine producing neurons in the midbrain resulting in tremors and slow muscle movement, cause unknown

Alzheimer's

build up of plaques and tangles in the brain that block communication and delivery of nutrients, a progressive disease with an unknown cause and cure.

shingles

a reactivation of the chickenpox virus in the body, causing a painful rash. The spinal cord is affected

describe the major functions of the brain stem...

the brain stem regulated vital basic functions like regulation of heart rate, breathing, sleeping, and eating

describe the major functions of the medulla...

carries out and regulates life sustaining that are done involuntarily (without thinking).

describe the major functions of the pons...

connects the upper and lower parts of the brain

temporal lobe

responsible for processing auditory information from the ears

parietal lobe

processes sensory things that have to do with temperature, touch, and taste

frontal lobe

carries out higher mental processes such as thinking, decision making, and planning. (This is where our personality is formed

occipital lobe

responsible for processing visual information from the eyes. It helps you correctly understand what you are seeing

how does nicotine affect the nervous system?

Nicotine acts on the CNS and PNS. The rapid affects of nicotine include faster respiration, construction of arteries, and it stimulates the central nervous system

describe the major functions of the cerebral cortex

the cerebral cortex is where the four lobes are located

pituitary gland

it is referred to as the body's "master gland" because it controls the activity of most other hormone-secreting glands

hypothalamus gland

the section of the brain responsible for the production of many of the body's essential hormones. It's chemical substances help control different cells and organs

what is a gland?

a gland is an organ that synthesizes a substance

what hormones do the Hypothalamus Gland produce?

it produces dopamine and somatostaton

how does caffeine affect the nervous system?

caffeine is an odorless, but bitter, white powder that has the ability to stimulate the CNS

how does alcohol affect the nervous system?

alcohol can contract brain tissues, destroys brain cells, as well as depresses the CNS

how does marijuana affect the nervous system?

tetrehydrocannabinol (THC) acts on the cannabinoid receptors which are found on neurons in many places in the brain. It affects the hippocampus, cerebral cortex, and cerebellum

what is the job of the spinal cord?

the spinal cord functions primarily in the transmission of the neural signals between the brain and the rest of the body

the cerebrum cortex is...

associated with higher brain function such as thought and action

what hormones come from the pituitary gland?

the adrenocorticotrophic hormone (ACTH) stimulates the production and release of cortisol from the cortex and the andrenal gland.

the growth hormone (GH) participates in regulating the body's metabolism

what hormones do the thalamus produce?

anti-diuretic hormone

ADH travels in the blood stream to you kindneys so more water is reabsorbed into your blood

oxytocin

stimulates the uterine muscles to contract

what is a thalamus gland?

the thalamus serves as a relay station for impulses traveling to and from the spinal cord, brain stem, cerebellum, and cerebrum

describe the major functions of the cerebellum...

responsible for balance and coordination of muscles and the body. It is extremely important for being able to preform everyday voluntary things

what is a hormone?

hormones are chemical substances that act like messenger molecules in the body

describe the function of each sense organ...

touch-skin

smell-nose

taste-tongue

hearing-ear

sight-eyes

cerebral palsy

A congenital disorder of movement, muscle tone or posture due to abnormal brain development...the cerebral cortex is affected

glaucoma

a group of eye conditions that can cause blindness. The visual cortex is affected

epilepsy

Also known as seizure disorder, it is a disorder in which nerve cell activity in the brain is disturbed, causing seizures

multiple sclerosis

a disease in which the immune system eats away at the protective covering of the nerves. The brain and spinal cord are affected

Alzheimer's disease

a progressive disease that that destroys memory and other important mental functions. The condition affects the cerebral cortex and hippocampus

Parkinson's disease

a disorder of the CNS that affects movement, often including tremors

Nervous system

Major communication system in the body. Functions in sensing, processing, communicating between the cells throughout the entire body

Central Nervous system

Consists of the brain and spinal cord

Peripheral nervous system

Extends from the spinal cord out to the entire body. Touch and feeling travels through neurons in the peripheral nerves through the afferent pathway to the spinal cord/brain

Somatic response

Signals travel from the brain down efferent pathway to muscles/neruons

Neurons

Interconnect and communicate with each other. From the brain to spinal, to peripheral nerves, to the effector organs to allow us to react to our surroundings. Use electrical and chemical signals

Action potential

Sending of message leads to chemical release (neurotransmitter)

Brain and spinal cord

Delicate/semisolid structures that require support and protection. Bone (skull, vertabrae), meninges (membranes), fluid (CSF)

Ventricles

Cavities filled with CSF, lined with ependymal cells

Schwann cells

Myelinate peripheral nerves a single nerve at a time

Myelin

Protect axon from outside ions. Act like electrical tape. Made from schwann cells in the periphery and oligodendrocytes in the CNS

Subdural hematoma

Brain injury resulting in leakage of blood beneath/within dura layer

Cerebrum

Most of the brain function. Higher level cognitive functions. Sensory integration, movement initiation, memory, emotion, consciousness

Brain stem

Autonomic funtions. Cardiovascular, respiratory control

Soma

Houses most organelles in a neuron. Main part of the neuron