biological psychology ch 1

input zone and parts

where neurons collect and integrate information, either from the environment or from other cells; dendrites, cell body

integration zone

where the decision to produce a neural signal is made

conduction zone & parts

where information can be transmitted over great distances; axon

output zone & parts

where the neuron transfers ifnormation to other cells; axon terminals

Motoneurons (motor neurons)

stimulate muscles or glands

sensory neurons

respond to environmental stimuli, such as light, odor, or touch

interneurons

receive input from and send input to other neurons, tend to be multipolar neurons

What are the 3 components of a synapse?

presynaptic membrane, synaptic cleft, postsynaptic membrane

presynaptic membrane

on the exon terminal of the presynaptic neuron

synaptic cleft

a gap that separates the membranes

postsynaptic membrane

on the dendrite or cell body of the postsynaptic neuron

synaptic vesicles

small spheres in presynaptic axon terminals that contain a neurotransmitter

What determines the release of neurotransmitters?

Neurotransmitters release in response to electrical activity in the axon

receptors

in the postsynaptic membrane, specialized proteins that react to a neurotransmitter

dendritic spines

outgrowths that are studded across the dendrite which increase surface area

What determines the number and structure of dendritic spines?

they can be rapidly altered by experience, facilitating the continual remodeling of connections between neurons (neural plasticity)

At what point is neural plasticity at its height?

during childhood

axon hillock

a cone-shaped area of the cell body that gives rise to the axon

axonal transport

the movement of materials within an axon via motor proteins

Glial Cells

support and enhance neural activity, they can communicate with each other and neurons

What are the 4 different types of glial cells?

astrocytes, microglial cells, oligodendrocytes, schwann cells

Astrocytes

star shaped cells with many processes that receive neuronal input and monitor activity. Controls flow of resources

microglial cells (microglia)

small cells that remove debris from dead, damaged cells; debris from nervous system. If job is not being done correctly then brain debris buildup can occur. CLEAN UP CREW!

Oligodendrocytes

glial cells that form myelin sheath in the brain and spinal cord

schwann cells

provide myelin to cells outside brain and spinal cord

myelination

the process in which glial cells wrap axons with a fatty sheath, myelin, to insulate and speed conduction

Nodes of Ranvier

gaps between sections of myelin where the axon is exposed

What happens if too many glial cells divide?

tumors can form

How do glial cells respond to injury?

edema/swelling

Astrocytes influence brain chemistry and have been implicated in ____

epilepsy

Microglia have been implicated in…

degenerative diseases, such as Alzheimer’s. Can be due to microglia not doing an adequate job or not having enough.

multiple sclerosis

a demyelinating disease

Peripheral Nervous System (PNS)

all parts of the nervous system found outside the skull and spinal column. Consists of nerves.

Central Nervous System (CNS)

consists of brain and spinal cord. Some nerves, motor nerves, transmit information from here to the muscles, organs, and glands. Sensory nerves also convey information from the body to here.

The nerves of the body are divided into what 2 systems?

somatic and autonomic nervous system

Somatic nervous system

nerves that interconnect the brain and the major muscles and sensory systems

Autonomic nervous system

nerves that primarily control the viscera

cranial nerves

12 pairs; some of which are exclusively sensory nerves, some are exclusively motor nerves, while some have both functions

spinal nerves

or somatic nerves, 31 pairs

each spinal nerve is the fusion of two distinct branches, or roots which are?

dorsal (back) root & ventral (front) root

dorsal (back) root

carries sensory information from the body to the spinal cord

ventral (front) root

carries motor information from the spinal cord to the muscles

sympathetic nervous system

this activation prepares the body for action (fight or flight)

parasympathetic nervous system

this activation is often in opposition to sympathetic activity. Rest and digestion

cerebral cortex

the thick, outermost sheet of the cerebral hemispheres, comprised mostly of neuronal cell bodies, dendrites, and axons.

gyri (gyrus)

ridges or riased portions of the convoluted brain surface

sulci (sulcus)

furrows of the convoluted brain surface (sulking-low)

sagittal plane

bisects the body into right and left halves

coronal plane

divides the body into front (anterior) and back (posterior) regions

horizontal plane

divides the brain into an upper and lower part

medial

towards the middle

lateral

towards the side

Ipsilateral

same side

Contralateral

opposite side

anterior or rostral

head end

posterior or caudal

tail end

proximal

near the center

distal

toward the periphery

afferent

carrying information into a region of interest

efferent

carrying information away from a region of interest

frontal

most anterior region

parietal

region between the frontal and occipital lobe

occipital

posterior region, visual processing

temporal

lateral region, auditory processing

sylvian fissure (lateral sulcus)

boundary of the temporal lobe

central sulcus

divides the frontal lobe from the parietal lobe

postcentral gyrus

strip of cortex behind the central cortex that is important for touch

precentral gyrus

in the frontal lobe, important for motor control

corpus callosum

a bundle of axons that connects the two cerebral hemispheres, allows for brain hemispheres to share information

basal ganglia

important in motor control. includes caudate nucleus, putamen, and globus pallidus

limbic system

includes structures important for learning and memory: amygdala, mammillary bodies, hippocampus, fornix (memory) and septal nuclei (reward & reinforcement in learning)

what are the 2 main components of the diencephalon?

thalamus and hypothalamus

thalamus

cluster of nuclei that relays sensory information

hypothalamus

contains nuclei with many vital functions; also controls pituitary

cerebellum

elaborately convoluted; involved in motor coordination and learning; consists of three layers

pons

attached to the cerebellum and contains motor control and sensory nuclei and gives rise to cranial nerves

medulla

contains cranial nerve nuclei and marks the transition from brain to spinal cord. contains nuclei that regulate breathing and heart rate. all axons from the brain to the spinal cord pass through here.

The brain and spinal cord are surrounded by three protective membranes, the meninges which are:

dura meter, pia meter, arachnoid

dura mater

tough outermost sheet of protective membrane

pia mater

delicate innermost protective membrane layer

arachnoid

substance between the dura mater and pia mater that cushions the brain is cerebrospinal fluid.

ventricular system

a series of chambers filled with cerebrospinal fluid

what is the function of cerebrospinal fluid?

acts as a shock abosrer and provides an exchange medium between blood & brain

action potential

a rapid electrical signal that travels along the axon of a neuron, triggers the release of neurotransmitters

neurotransmitter

a chemical messenger between neurons that is released into synapses

resting membrane potentional

-50 to -80 mV that shows the negative polarity of the cell’s interior

The neuron shows selective permeability meaning..

it allows K+ to freely enter or leave the cell, but restricts the flow of other ions

diffusion

causes ions to flow from areas of high to low concentration, along their concentration gradient

electrostatic pressure

causes ions to flow towards oppositely charged areas

sodium-potassium pump

neurons use this mechanism to maintain resting potential. Pumping 3 Na+ ions out for every 2 K+ pumped in. (this is a pump therefore an active process)

At rest ___ channels are open, while ___ channels are closed.

Potassium; Sodium

action potentials are brief but large changes in the? Which originate in the?

membrane potential; axon hillock

Patterns of action potentials

carry information to postsynaptic targets

hyperpolarization

an increase in membrane potential- the interior of the membrane becomes even more negative , relative to the outside

depolarization

a decrease in membrane potential- the interior of the cell becomes less negative. (if depolarized enough, a cell will fire)

graded response

the change in potential; the greater the stimulus the greater the response

action potentials are produced by the movement of what ions?

Na+ ions

refractory period

time when only some stimuli can produce an action potential

absolute refractory phase

time when no action potentials are produced