Unit 3: The Body's Systems Flashcards
Cell body
The part of a neuron that contains the nucleus; the cell’s life support center
Dendrites
Receive and integrate messages, conduct impulses toward the cell bodys
What happens when degeneration of the myelin sheath occurs?
Multiple sclerosis
Glial cells (glia)
THINK: Glidal = guiding
Cells in the nervous system that support, nourish, and protect neurons; also play a role in learning, thinking, and memory
Action potential
A neural impulse; a brief electrical charge that travels down an axon
Refractory period
A brief resting pause that occurs after a neuron has fired; A.P cannot occur until the axon returns
synapse
The junction between the axon tip of the sending neuron and the dendrite/cell body of the receiving neuron
Synaptic cleft
The gap at the junction between the axon tip and the dendrite/cell body of the receiving neuron
Neurotransmitters
Chemical messengers that cross synaptic clefts between neurons
Reuptake
When a neurotransmitter is reabsorbed by a sending neuron
Agonist molecule
A molecule that increases neurotransmitter action
Antagonist molecule
A molecule that decreases neurotransmitter action
Cerebral cortex
The fabric of connected neuron cells covering the cerebral hemispheres. The body’s ultimate control and information processing center.
Parietal lobe
THINK = parent
Top of the head and toward the rear; Sensory input for touch, pain, and body position
Frontal lobes
THINK = front of the wheel
Behind the forehead; speaking, muscle movements, memory, thinking, learning, judgments
Occipital lobes
THINK = oculus
Back of the head; receive information from visual fields
Temporal lobes
THINK = temp, there to step in for front (off to the side)
Above the ears; includes auditory areas, receives info from opposite ears
Motor cortex
Back of the frontal lobes; controls voluntary movements
Somatosensory cortex
Font of the parietal lobes; registers movement and touch
Association areas
THINK: association = power
Areas of the cerebral cortex not involved in primary motor or sensory functions.
–> Involved in higher mental functions such as learning, remembering, thinking, and speaking
Broca’s area
Left frontal lobe; affects speaking
Wernicke’s area
Left meeting place of lobes; affects understanding
Plasticity
The brain’s ability to change by reorganizing after damage based on experience
Neurogenesis
The formation of new neurons
Corpus callosum
The large band of neural fibers connecting the two hemispheres and carrying messages between them
Split brains
Results from surgery that isolates the two hemispheres by cutting the corpus callosum
Dual processing
Information is often simultaneously processed on separate conscious and unconscious tracks
Nervous system
Electrochemical network; takes in information from the world & the nerve cells
Central Nervous System
The brain and spinal cord; the decision maker
Peripheral Nervous System
Gathers information; transmits CNS decisions to other body systems or parts
Sensory (afferent) neurons
Carries messages from the tissues and sensory receptors inward to CNS
Motor (efferent) neurons
Carries instructions from CNS to muscles and glands outward
Interneurons
Between sensory and motor; processes information
Somatic nervous system
Part of the peripheral nervous system; voluntary control of skeletal muscles
Autonomic nervous system
Part of the peripheral nervous system, controls glands and internal organ muscles
Sympathetic nervous system
Arouses and expends energy
Parasympathetic nervous system
Calms down and undoes sympathetic nervous system
Neural networks
Clusters of neurons
Spinal reflex pathway
Sensory —-(interneuron)—- motor
Pain reflex pathway
Neural activity –> Sensory neurons –> Muscles
Endocrine system
Secondary chemical communication system; a set of glands that send hormones into the bloodstream
Hormones
Travel through the bloodstream into tissues
Adrenal glands
Above kidneys; secrete hormones (epinephrine and norepinephrine) that arouses body during stress
Pituitary gland
Most influential gland, located in the core of the brain and controlled by the hypothalamus
Oxytocin
Associated with birth, milk, flow, and orgasm; social bolding, pair bonding trust
Feedback system
Brain –> Pituitary –> Other glands –> Hormones –> Body and brain
Electroencephalogram (EEG)
THINK: electro
Electrode placed on scalp to measure electrical activity in neurons
Magnetoencephalography (MEG)
THINK: magnet
Coil records magnetic fields from the brain’s electrical currents
Computed Tomography (CT)
THINK: x-ray slices
Xrays of the head that may locate brain damage
Postron Emmission Tomography (PET)
THINK: radioactive drug
Tracks where a temporarily radioactive form of glucose goes while the brain performs a given task
Magnetic Resonance Imaging (MRI)
THINK: N, B, O, V
Uses magnetic fields and radio waves; tracks nerves, bones, organs, vessels
Functional Magnetic Resonance Imaging (fMRI)
THINK: MRI + what?
Measures blood flow to brain regions by comparing continuous MRI scans (MRI + bloodflow)
Brain connectivity
Helps further understand how different brain regions work together
Brainstem
Oldest and innermost region, responsible for automatic survival functions, on top of medulla
Medulla
Base of brainstem, controls heartbeat and breathing
Pons
Coordinates movements and sleep
Thalamus
THINK: router
On top of the brainstem; directs messages to the sensory receiving areas in the cortex and sends to cerebellum and medulla
Reticular formation
Between ears in brainstem; travels through brainstem to thalamus, controls arousal
Cerebellum
THINK: Ring the bell, you fall!
Rear of brainstem; balance, coordination, motor skills, enables nonverbal learning and memory
Limbic system
THINK: ex-boyfriend
Neural system below the cerebral hemispheres; associated with drives between old and new brain areas
Parts of the limbic system
1) Amygdala
2) Hypothalamus
3) Hippocampus
Hypothalamus
THINK 4 F’s:
Fighting, Fleeing, Feeding, F’ing…
Below thalamus; maintenance activities such as hunger, thirst, body temperature, sex, sleep
Hippocampus
THINK: hippo looks like?
Neural center in limbic system; conscious memories of facts and events
Heredity
The genetic transfer of characteristics from parents to offspring
Genome
Consists of all the genetic material in an organism’s chromosomes
Heritability
The extent to which variation among individuals in a group can be attributed to different genes
Epigenetics
Studies molecular mechanisms by which environments can trigger or block genetic expression
Pineal glands
Involved in producing melatonin
Thyroid glands
Regulates metabolism
Adrenal glands
Produces adrenaline to help with crisis
Pancreas
Produces insulin to help get energy from food
Ovary
Produces estrogen and progesterone
Testes
Produces testosterone
Adrenaline
Involved in fight or flight, beneficial in short bursts
Leptin
Turns off hunger
Ghrelin
Turns on hunger
Genetic mutation
A random error in a gene replication that leads to change
Sexual overperception bias
Men perceive people to be more into them than they actually are
