BIOL 322 Neuroscience

Module 1 Problem Set

Neuroscience is the study of

the nervous system

What is the main function of neurons (basic units of the brain)

• to send and receive information throughout the body

• They use electrical and chemical signals to help the brain communicate with the body

Dendrites

• processes that branch out in a tree-like fashion from the cell body

• the main target for incoming signals received from other cells

Cell Body

• contains the nucleus and cellular organelles, including the endoplasmic reticulum, Golgi apparatus, mitochondria, ribosomes, and secretory vesicles

• Information arrives through the dendrites of a neuron and filters to the cell body

The axon is the

main output extension of the neuron

myelin sheath

• axons are covered in them

• fatty substance that wraps around portions of the axon and increases signal conduction

Unipolar neurons

have one extension off the cell body that acts as both the receiving and sending end

bipolar neurons

have one dendrite and one axon

multipolar neurons

• contains on the axon and numerous dendrites

• the most common among all neurons in the human nervous system

Motor (efferent) neurons

carry information from the central nervous system to the body

Sensory (afferent) neurons

obtain information from the outside world or the internal environment and send it to the central nervous system

% major types of glial cells

1. Schwann cells

2. oligodendrocytes

3. astrocytes

4. microglia

5. ependymal cells

Schwann cells

Provide a section of the myelin sheath for the peripheral nervous system neurons

oligodendrocytes

add a layer of myelin around the axons of nearby neurons, but in the central nervous system

astrocytes

• In the brain, help maintain the blood-brain barrier

• closely associated with the synapses, the junctions between neurons

• synthesize and produce a variety of trophic factors

Microglia

• more immune cells than neural

• act as cellular scavengers that travel throughout the brain and spinal cord

• As immune cells, they identify and destroy clumps of proteins, dead/dying cells, or foreign pathogens that enter the brain

ependymal cells

• lining of glia inside the ventricles

• columnar with small fingerlike extensions called cilia that extend into the ventricles and into the central canal that runs down the inside of the spinal cord

• produce (CSF) cerebrospinal fluid

What are the two main branches of the nervous system

1. central nervous system (CNS)

2. peripheral nervous system (PNS)

the central nervous system (CNS) is the

brain and spinal cord

peripheral nervous system (PNS) is

all the other nerve cells in the body in the periphery

Anterior

in front of; toward the face

posterior

behind; toward the back

superior

above; toward the head

inferior

below; toward the feet

medial

toward the middle

lateral

toward the edge

dorsal

toward the top of the brain or the back of spinal cord

ventral

toward the bottom of the brain or front of the spinal cord

Rostral

toward the front the brain or top of the spinal cord

caudal

toward the back of the brain or bottom of the spinal cord

gyrus

the bumps or raised ridges on the outer surface

sulcus

the grooved indentations between the gyri

What are the four main lobes of the brain

1. frontal lobes

2. parietal lobe

3. temporal lobe

4. occipital lobe

Frontal lobe

• responsible for higher-level executive functions like attention, critical thinking, and impulse control

parietal lobe

• contains the primary somatosensory cortex

• responsible for the perception of touch and pain

• perform higher-level visual processing

temporal lobe

• plays a role in sensory processing, specifically with hearing, smell, taste, and higher-level visual processing

occipital lobe

responsible for the processing of visual stimuli

what is the function of the hypothalamus

• An autonomic control center to alter visceral function and a communication route to the body’s endocrine system through control of anterior pituitary hormones and production of posterior pituitary hormones.

• Neural signals originating in the hypothalamus have the capability to influence the chemistry and function of the entire body

• also has nuclei that function in emotional responses and regulate body temperature, food intake, water balance, and sleep

what is the function f the cerebellum?

regulation and control of movement, but is also involved in cognitive functions like emotions

what are the four regions of the spinal cord

1. cervical region (C1 through C7)

2. thoracic region (T1 through T12)

3. lumbar region (L1 through L5)

4. sacral region (S1 through S5)

The dorsal root is an example of a

sensory (afferent) nerve that is responsible for carrying information toward the central nervous system

The ventral root is an example of a

motor (efferent) nerve that is resposible for carrying information away from the central nervous systemn

White Matter

• represents pathways of communication

• composed of axons

• appears white due to the myelin sheath on the axons

gray matter

• dense with cell bodies and dendrites

• location of most synapses

What are the three main branches of the peripheral nervous system

1. Sensory

2. somatic

3. autonomic

Somatic nervous system

• represents all the parts of the PNS that are involved with the outside environment, either in sensing the environment or acting on it

• the branch that sends signals to skeletal muscles

Autonomic nervous system

encompasses all the branches of the peripheral nervous system that deal with the internal environment

enteric nervous system

• consists of the network of neurons that causes the digestive tract to increase or decrease the rate of these processes depending on the body’s demands.

• The enteric nervous system receives signals from both the sympathetic and parasympathetic nervous systems and functions without our conscious knowledge. 

Sympathetic nervous system

prepares your body for stress or emergencies (fight or flight)

parasympathetic nervous system

Responsible for the physiological response known as the rest-and-digest response.

Identify the difference between the two-neuron pathway in the sympathetic and parasympathetic divisions.

The sympathetic division has a short preganglionic neuron and a long postganglionic neuron. While the parasympathetic division has a long preganglionic neuron and a short postganglionic neuron.

how many cranial nerves are there and what re they

1. olfactory

2. optic

3. oculomotor

4. trochlear

5. trigeminal

6. abducens

7. facial

8. vestibulocochlear

9. glossopharyngeal

10. vagus

11. accessory

12. hypoglossal

olfactory

smell

optic

vision

oculomotor

moves the eyes and controls pupil size

trochlear

moves the eye

trigeminal

feeling in the face and chewing

abducens

moves the eye sideways

facial

facial expressions and taste

vestibulocochlear

hearing and balance

glossopharyngeal

taste and swallowing

vagus

controls organs like the heart, lungs, and digestive system

accessory

moves the neck and shoulders

hypiglossal

moves the tongue

what is a dermatome

a specific area of the skin that carries information to the spinal cord and ultimately to the brain through a particular pair of spinal nerves.

The left and right vertebral arteries merge into a single basilar artery, and along with the left and right internal carotid arteries, feed into a loop-like circular blood vessel called

circle of willis

what is the function of the blood-brain barrier

an anatomical adaptation that selectively transports substances necessary for normal biological function, while simultaneously excluding potentially harmful invaders from the brain.

what is the function of the meninges

A series of protective membranes that minimize damage to the CNS

what are the three layers of the meninges

1. dura mater

2. arachnoid mater

3. pia mater

dura mater

made of thick, fibrous material and can get to be 0.8 mm thick in the adult body. The dura mater is physically attached to the inside of the skull with highly resilient connections found at the sutures between the plates of the cranium. 

arachnoid mater

is the middle layer of the meninges. The fibers are very delicate and resemble a spider web, which is where the name comes from. Within this space, there are protrusions that allow for CSF to drain into sinuses, which allow for recycling of soluble substances. Most of the CSF in the brain exists underneath this layer in the subarachnoid space.

pia mater

the third layer of the meninges. It is very fragile, is in direct contact with the surface of the brain, and closely follows the sulci and gyri. 

What is the purpose of cerebrospinal fluid (CSF)

allows the brain to remain “floating” inside the skull. This liquid serves as a form of “cushioning” that protects the brain from rapid head movements. CSF can also function as a way to wash impurities out of the brain.