Biopsychology Exam 1

within the skull and spinal column

Where is the central nervous system (CNS) located?

analyzing incoming information

What is the purpose of the CNS?

outside the skull and spinal column

Where is the peripheral nervous system (PNS) located?

messenger that allows info to travel to/from the CNS

What is the purpose of the PNS?

1. Somatic nervous system

2. Autonomic nervous system

What are the two subdivisions of the PNS?

involved with EXTERNAL sensations, takes info from the outside (sound, smell, etc) and sends to the brain. Also responsible for VOLUNTARY skeletal movements (blinking, grabbing)

What is the purpose of the somatic nervous system?

involved with INTERNAL sensations (stomach hurts). Also responsible for INVOLUNTARY/AUTOMATIC responses (blood vessels changing size, digestion, heart rate)

What is the purpose of the autonomic nervous system?

ACCEPTING signals to the CNS. SENSORY information from muscles/joints/etc

What is the purpose of afferent nerves?

EXITING the CNS. MOTOR signals from CNS to muscles

What is the purpose of efferent nerves?

activation of system (prepare for action)

ex: Dilates pupils, accelerates heartbeat, inhibits digestion

What is the purpose of the sympathetic division of the autonomic nervous system?

action of system (relax, recuperate)

ex: Constricts pupils, constricts airways, slows heartbeat, stimulates digestion

What is the purpose of the parasympathetic division of the autonomic nervous system?

Soma

cell body. contains majority of organelles; organelles involved in various functions

Nucleus

within the cell body. contains DNA which is used to influence neuronal function

Dendrites

branch-like extensions from cell body which have receptors that become stimulated from outside signals (receives messages)

Axon hillock

cone-shaped location which connects the cell body to the axon. This is where electrical signals sum together and where the action potential starts

Axon

cord-like extension from soma via axon hillock. conducting electrical impulses away from soma (sends messages)

Myelin sheath

fatty bilayer which covers axons and helps speed up neuronal transmissions

Nodes of ranvier

unmyelinated segment on the axon measuring about 1 micrometer in length. Involved in saltatory conduction/speeding up neuronal transmission

What is the axon terminal?

ends of axon which branch out into knobs, forming a synapse on another neuron or other cell target (often referred to as presynaptic terminal when signaling)

Multipolar neuron

MULTIple dendrites, 1 axon (typical image of neuron)

Bipolar neuron

1 dendrite, 1 axon (2 lines with bulbous looking soma in middle)

Pseudounipolar neuron

0 dendrites, 2 branching axons. Sends AND receives signals. (very weird one)

Sensory category of neuronal function

carries info from periphery to CNS. Pseudounipolar. AFFERANT. “A” for Accepted by the CNS

Motor category of neuronal function

carries info from CNS to muscles. Multipolar. EFFERANT. “E” for Exiting the CNS

Interneuron category of neuronal function

contained in CNS, don’t extend far. Communicates between sensory and motor neurons inside the CNS. Multipolar. Quick, automatic responses, like reflexes (stepping on lego)

Astrocyte (glial cell)

star-shaped, form the blood-brain barrier and clean up waste

Microglia (glial cell)

smallest, act as the CNS’ immune system. Target disease, break down damaged cells.

Promote growth

Oligodendrocyte (glial cell)

found in CNS, produces nodes of ranvier

Schwann Cell (glial cell)

found in PNS, produces bundles of myelin around axon

Sodium (Na+)

positive charge – Wants to move into the cell

Potassium (K+)

positive charge - Wants to move into the cell

Chloride (Cl-)

negative charge - Wants to move out of the cell

threshold for action potential

-55 mV

The sodium-potassium pump works to restore ion balance by trading 3 Na+ out for every 2 K+ ions in

How is ion balance restored?

resting potential of a neuron

-70 mV

Depolarization

when the cell becomes more positive

Hyperpolarization

when the cell becomes more negative

Absolute refractory period

At the peak, the axon cannot generate another AP because Na+ channels are closed and are in a short inactive state where they CANNOT reopen

Relative refractory period

On the downward turn, another AP can be generated, but a stronger stimulus is needed.

Presynaptic cell

The cell that is delivering a signal

Postsynaptic cell

The cell that is receiving a signal

Temporal summation

Repeated stimuli have a cumulative effect

- Continuously activating the same neuron within a short time frame (squeezing dog paw at random times in same spot)

Spatial summation

Stimuli at separate, but close locations have a cumulative effect and trigger a nerve impulse

- Sending multiple synaptic inputs to a neuron at the same time (squeezing dog paw in random spots but similar area)

Excitatory postsynaptic potential (EPSP)

temporary depolarization of a membrane

Inhibitory postsynaptic potential (IPSP)

temporary hyperpolarization of a membrane

Glutamate

major excitatory NT. EPSP (opens sodium channels)

GABA

major inhibitory NT. IPSP (opens potassium or chloride channels)

Acetylcholine

NT with role in movement/muscle contraction

Dopamine

NT important for initiation/smoothness of movement, reward, pleasure, decision-making

Serotonin

NT important for stable mood. Major target for antidepressant drugs

Transporter receptors

special membrane proteins that facilitate reuptake (PRESYNAPTIC)

Autoreceptors

receptors that detect the amount of transmitter released and inhibit further synthesis & release (PRESYNAPTIC)

Ionotropic receptors

receptor that uses ligand gated channel, occurs quickly (POSTSYNAPTIC)

Metabotropic receptors

receptor that uses signal proteins, slower (POSTSYNAPTIC)

Neurotransmitters

chemicals that travel across the synapse and allow communication between neurons

Neuropeptides

EPSPs who’s release requires repeated stimulation. Effects are long lasting. Important for long-lasting behaviors like hunger and thirst

Hormones

chemicals secreted by a gland (or other cells) to be transported to other organs by the blood, and then alters activity there. Made by chains of amino acids

Dorsal

toward the back; toward the top of the head (forehead up)

Ventral

toward the chest; toward the bottom of the head (forehead down)

Anterior

towards the front/nose

Posterior

towards the back/butt

Superior

towards the top of the brain; above another structure

Inferior

towards the bottom of the brain; below another structure

Medial

towards the midline of the body (spine/middle of brain)

Lateral

away from the midline of the body (moving to the sides)

Proximal

located closely to the point of attachment or origin

Distal

located more distant to the point of attachment or origin

Lamina

a row of cell bodies separated from other cell bodies by a layer of axons and dendrites

Column

a set of cells perpendicular to the surface of the cortex

Tract

a bundle of axons within the CNS

Nerve

a bundle of axons running from the PNS to the outskirts of the CNS

Nucleus

a cluster of neuron cell bodies within the CNS that are specialized in a certain function

Ganglion

a cluster of neuron cell bodies in the PNS that are specialized in a certain function

Gyri/Gyrus

a protuberance on the surface of the brain (thick fleshy bumps)

Sulci/Sulcus

a fold or groove that separates one gyri from another (the wrinkles)

Fissure

a long deep sulcus (grand canyon for brain)

Cerebral cortex

large outer portion of brain with 4 lobes

Divided into 2 hemispheres. Connected by 2 bundles of axons: Corpus callosum, Anterior commissure

Occipital lobe

important for vision. Contains the primary visual cortex. Damage can result in cortical blindness. (person is able to see but can’t process that they are seeing)

Parietal lobe

primary somatosensory cortex. important for somatic sensations (touch) and spatial awareness

Temporal lobe

primary auditory cortex. Essential for processing spoken language

Frontal lobe

prefrontal cortex, important for higher order functioning (planning, decision making, personality, etc.). Primary motor cortex, responsible for the control of fine motor movement

Thalamus

relay station from the sensory organs; main source of input to the cortex

Hypothalamus

Conveys messages to the pituitary gland to alter the release of hormones. “Four F’s” – fight, flight, feeding, fornication

Diencephalon

thalamus + hypothalamus

Pituitary gland

hormone-producing gland

Basal ganglia

Associated with the planning of motor movement. Critical for learned skills and habits.

Hippocampus

Critical for storing certain types of memory (new events). Episodic, Spatial navigation, Temporal. Seahorse shape

What is contained in the forebrain?

Cerebral cortex, thalamus, hypothalamus, pituitary gland, basal ganglia, hippocampus

What is contained in the midbrain?

Tectum, tegmentum, superior colliculus, inferior colliculus, substantia nigra

Tectum

“roof”/dorsal part of the midbrain

Superior colliculus

processes visual info and eye muscle movement

Inferior colliculus

processes auditory information

Tegmentum

”floor”/ventral part of the midbrain

Substantia nigra

gives rise to the dopamine-containing pathway facilitating readiness for movement

What is contained in the hindbrain?

Medulla, pons, cerebellum

Medulla

Responsible for vital functions needed for survival – breathing, heart rate, vomiting, salivation, coughing & sneezing. YOU WILL DIE IF IT IS DAMAGED!!!!!

Pons

relays sensory and motor info between the cerebellum and cerebrum

Cerebellum

helps regulate motor movement, balance, coordination

Ventricles

4 brain cavities filled with cerebrospinal fluid

Cerebrospinal fluid

Fluid found in brain and spinal cord. Cushions brain, reservoir for hormones and nutrition, removes chemical wastes