Physiology Quiz 1

Afferent neuron

Brings signals from sensory organs to the brain

Efferent neuron

Brings signals from the brain to effector organs

Nerve net

Present in organisms with radial symmetry, lacks cephalization

Cephalization

Nerve tissues localized in the anterior body, forming a command center for the nervous system

Ganglion

Cluster of neuronal cell bodies

Central nervous system

Consists of the brain and the spinal cord

Peripheral nervous system

Cranial and spinal nerves, axons of efferent motor neurons, connects CNS to muscles, glands, and sensory receptors

Gyri

Bumps/ridges of the brain

Sulci

Grooves/valleys of the brain

Gray matter

Neuronal cell bodies

White matter

Myelinated axons

Dorsal root ganglion

Carries sensory information from the peripheral nervous system to the central nervous system

Ventral root

Carries motor information from the central nervous system to the peripheral nervous system

Forebrain

The cerebrum, which contains the cerebral cortex, basal ganglia, hippocampus, amygdala, thalamus, hypothalamus, and olfactory bulbs

Midbrain

Contains the superior and inferior colliculi

Hindbrain

Contains the medulla oblongata, pons, and cerebellum

Frontal lobe

Lobe of the cerebral cortex responsible for reasoning, planned action and movements, and decision making

Parietal lobe

Lobe of the cerebral cortex responsible for mechanosensory processing

Occipital lobe

Lobe of the cerebral cortex responsible for visual processing

Temporal lobe

Lobe of the cerebral cortex responsible for auditory processing

Broca’s area

Leftside area of the frontal lobe responsible for speech production

Wernicke’s area

Leftside area responsible for speech comprehension

Central sulcus

Separates the frontal lobe from the parietal lobe

Sylvian fissure

Separates the temporal lobe from the parietal lobe

Somatosensory cortex

Area of the parietal lobe responsible for receiving information about tactile stimuli

Corpus callosum

Band of white matter that connects the left and right hemispheres

Limbic system

Contains the thalamus, hypothalamus, amygdala, and hippocampus

Thalamus

Conveys sensory information to the cerebral cortex

Hypothalamus

Maintains homeostasis (body temperature, hydration, eating, blood pressure, breathing)

Amygdala

Produces fight or flight response, emotions of aggression, rage, fear, and anxiety

Hippocampus

Responsible for memory and long-term learning

Superior and inferior colliculi

Relay visual and auditory information, produce reflexive action

Medulla oblongata

Regulates respiration, blood pressure, and heart rate

Pons

Relays information between the spinal cord, cerebellum, and cerebral cortex, controls breathing and blood pressure

Cerebellum

Integrates sensory information, movement coordination, balance, fine motor skills, and motor memory

Olfactory Nerve

Cranial nerve I, sensory, nose

Optic nerve

Cranial nerve II, sensory, eyes

Oculomotor nerve

Cranial nerve III, motor, eyes

Trochlear nerve

Cranial nerve IV, motor, superior oblique eye muscle

Trigeminal nerve

Cranial nerve V, both, senses of face, teeth, and sinuses and movement of mastication muscles

Abducent nerve

Cranial nerve VI, motor, external rectus eye muscle

Facial and intermediate nerve

Cranial nerve VII, both, facial moves face muscles and intermediate responsible for senses of anterior tongue and soft palate and movement of the submaxillary and sublingual glands

Vestibulocochlear nerve

Cranial nerve VIII, sensory, inner ear

Glossopharyngeal nerve

Cranial nerve IX, both, senses of posterior tongue, tonsils, pharynx and movement of pharynx

Vagus nerve

Cranial nerve X, both, senses of heart, lungs, bronchi, GI tract, trachea, larynx, pharynx, and external ear and movement of heart, lungs, bronchi, and GI tract

Accessory nerve

Cranial nerve XI, motor, sternocleidomastoid and trapezius muscles of the neck

Hypoglossal nerve

Cranial nerve XII, motor, muscles of the tongue

Meninges

Protective layer around the brain containing the dura mater, arachnoid mater, and dura mater, with cerebrospinal fluid in between

Dura mater

Tough outer layer of the meninges

Arachnoid mater

Web-like middle layer of the meninges

Pia mater

Thin inner layer of the meninges

Ventricular system

Pockets within the brain filled with cerebrospinal fluid that help to protect the brain

Cerebrospinal fluid

Liquid produced by choroid plexus cells, used for nutrition, waste removal, and protection of the brain

Blood brain barrier

Tight connections within blood vessels that prevent the movement of molecules out of the vessels

Astrocytes

Cells that wrap around cranial blood vessels and further seal vessels

Autonomic nervous system

Maintains homeostasis and mediates responses to changes in the environment

Parasympathetic nervous system

Rest and digest system, slows heart rate, increases intestinal activity, and relaxes muscles, controlled by top and base of spine

Sympathetic nervous system

Fight or flight system, decreases digestion, increases heart rate, and dilates airways, controlled by mid spine

Neurons

Electrically excitable nerve cells that can receive and transmit signals

Glia

Nerve cells that provide mechanical and metabolic support to neurons

Ependymal cells

Cells that line the spinal cord and ventricles, produce cerebrospinal fluid

Oligodendrocytes

Form myelin sheathes around multiple cells in the central nervous system

Microglia

Immune cells in the brain, remove debris and pathogens and cause inflammation

Satellite cells

Surround neuron cell bodies in the peripheral nervous system

Schwann cells

Form myelin sheaths in the peripheral nervous system, regenerate neurons after injury

Dendrites

Multiple outputs of the neuronal cell body that receive information, have spines and a tapering diameter

Axon initial segment/axon hillock

Shapes and generates information before it is conducted down the axon

Axon

Long, constant diameter outputs of neuron cell body that conduct information

Axon terminal

Site of neurotransmitter release, neurotransmitters generate signals in other cells

Graded potentials

Small changes in membrane potential in the dendrites and cell body, produce localized current across the membrane

Action potentials

Rapid depolarization and repolarization of the membrane potential in the axon

Voltage-gated sodium channels

Contain 4 highly homologous protein domains

Voltage-gaited potassium channels

Contain 4 distinct, homologous subunits

Pore loops

Make up the narrow neck of voltage-gated ion channels and determine ion selectivity

S4 region

Region of voltage-gated ion channels with positively charged amino acids that twist outwards during membrane depolarization, opening the ion channel

Inactivation loop

Loop of amino acids that blocks and inactivated sodium channels

Ball and chain

Protein region that blocks and inactivated potassium channels

Myelin

A lipid rich layer that coats the axons of some neurons, formed by glial cells

Saltatory conduction

Action potentials are only generated at the nodes of Ranvier, resulting in higher conduction velocities

Electrical synapses

Connections between neurons with gap junctions that allow ions to flow directly from one neuron to another, allow for rapid signal transduction

Chemical synapses

Use vesicles, neurotransmitters, and receptors to move action potentials from one neuron to another, resulting in a slight delay in postsynaptic action potential

Ionotropic receptors

Ligand-gated ion channels that open when neurotransmitters bind, allowing ions to flow into or out of the cell

Metabotropic receptors

G-protein coupled receptors that trigger downstream reactions upon the binding of a neurotransmitter, such as the opening of ion channels by second messengers

GABA

Most common inhibitory neurotransmitter in the brain, regulates anxiety, irritability, concentration, sleep, depression, etc.

Glycine

Most common inhibitory neurotransmitter in the spinal cord, controls hearing processing, pain transmission, and metabolism

Glutamate

Most common excitatory neurotransmitter and most abundant neurotransmitter in the brain, regulates cognitive functions, learning, and memory

Acetylcholine

Excitatory neurotransmitter released by neurons in the autonomic nervous system, regulates motor functions, muscle contractions, sleep, learning, memory

Serotonin

Excitatory neurotransmitter that regulates mood, sleep patterns, anxiety, appetite, and pain

Nicotinic receptor

Ionotropic acetylcholine receptor

Muscarinic receptor

Metabotropic acetylcholine receptor

Parasympathetic pathway

Postganglionic neuron releases acetylcholine, which acts on muscarinic cholinergic receptors at the effector organ

Sympathetic pathway

Postganglionic neuron releases norepinephrine, which acts on adrenergic receptors at the effector organ

EPSP

Excitatory post-synaptic potential

IPSP

Inhibitory post-synaptic potential

Synaptic plasticity

The functional processes of individual synapses can be modified by a variety of factors, including elevated electrical activity (experience)

Long term potentiation

The persistent strengthening of synapses based on recent patterns of activity