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action potential
a momentary change in the electrical potential of a neuron (or muscle) membrane
adrenal gland
the endocrine gland associated with the kidneys
(plural: alveoli) (also, air sacs) the terminal structure of the lung passage where gas exchange occurs
a structure within the limbic system that processes fear
an enzyme found in saliva and secreted by the pancreas that converts carbohydrates to maltose
the exit point of the digestive system for waste material
the major artery that takes blood away from the heart to the systemic circulatory system
appendicular skeleton
the skeleton composed of the bones of the upper limbs, which function to grasp and manipulate objects, and the lower limbs, which permit locomotion
a blood vessel that takes blood away from the heart
(plural: atria) a chamber of the heart that receives blood from the veins
auditory ossicles
(also, middle ear bones) the bones that transduce sounds from the air into vibrations in the fluid-filled cochlea
autonomic nervous system
the part of the peripheral nervous system that controls bodily functions
axial skeleton
skeleton that forms the central axis of the body and includes the bones of the skull, the ossicles of the middle ear, the hyoid bone of the throat, the vertebral column, and the thoracic cage (ribcage)
a tube-like structure that propagates a signal from a neuron’s cell body to axon terminals
basal ganglia
an interconnected collections of cells in the brain that are involved in movement and motivation
bicuspid valve
a one-way opening between the atrium and the ventricle in the left side of the heart
a digestive juice produced by the liver; important for digestion of lipids
a mass of food resulting from chewing action and wetting by saliva
a portion of brain that connects with the spinal cord; controls basic nervous system functions like breathing and swallowing
(singular: bronchus) smaller branches of cartilaginous tissue that stem off of the trachea; air is funneled through the bronchi to the region where gas exchange occurs in the alveoli
an airway that extends from the main bronchus to the alveolar sac
the smallest blood vessel that allows the passage of individual blood cells and the site of diffusion of oxygen and nutrient exchange
cardiac cycle
the filling and emptying the heart of blood caused by electrical signals that cause the heart muscles to contract and relax
cardiac muscle tissue
the muscle tissue found only in the heart; cardiac contractions pump blood throughout the body and maintain blood pressure
cartilaginous joint
a joint in which the bones are connected by cartilage
central nervous system (CNS)
the nervous system made up of the brain and spinal cord; covered with three layers of protective meninges
the brain structure involved in posture, motor coordination, and learning new motor actions
cerebral cortex
the outermost sheet of brain tissue; involved in many higher-order functions
cerebrospinal fluid (CSF)
a clear liquid that surrounds the brain and fills its ventricles and acts as a shock absorber
a mixture of partially digested food and stomach juices
closed circulatory system
a system that has the blood separated from the bodily interstitial fluid and contained in blood vessels
the largest portion of the large intestine consisting of the ascending colon, transverse colon, and descending colon
corpus callosum
a thick nerve bundle that connects the cerebral hemispheres
a structure that extends away from the cell body to receive messages from other neurons
a change in the membrane potential to a less negative value
a skeletal muscle located under lungs that encloses the lungs in the thorax
the relaxation phase of the cardiac cycle when the heart is relaxed and the ventricles are filling with blood
a decrease in the number of hormone receptors in response to increased hormone levels
an organism that relies primarily on environmental heat sources to maintain its body temperature
electrocardiogram (ECG)
a recording of the electrical impulses of the cardiac muscle
endocrine gland
the gland that secretes hormones into the surrounding interstitial fluid, which then diffuse into blood and are carried to various organs and tissues within the body
an organism that relies primarily on internal heat sources to maintain its body temperature
a tubular organ that connects the mouth to the stomach
essential nutrient
a nutrient that cannot be synthesized by the body; it must be obtained from food
exocrine gland
the gland that secretes chemicals through ducts that lead to skin surfaces, body cavities, and organ cavities.
fibrous joint
a joint held together by fibrous connective tissue
frontal lobe
the part of the cerebral cortex that contains the motor cortex and areas involved in planning, attention, and language
the organ that stores and concentrates bile
(also, glial cells) the cells that provide support functions for neurons
the brain structure in the temporal lobe involved in processing memories
a chemical released by cells in one area of the body that affects cells in other parts of the body
hyoid bone
the bone that lies below the mandible in the front of the neck
the brain structure that controls hormone release and body homeostasis
inferior vena cava
the major vein of the body returning blood from the lower parts of the body to the right atrium
interstitial fluid
the fluid found between cells in the body, similar in constitution to the fluid component of blood, but without the high concentrations of proteins
intracellular hormone receptor
a hormone receptor in the cytoplasm or nucleus of a cell
the point at which two or more bones meet
the organ that performs excretory and osmoregulatory functions
large intestine
a digestive system organ that reabsorbs water from undigested material and processes waste matter
the voice box, located within the throat
limbic system
a connected brain area that processes emotion and motivation
an organ that produces bile for digestion and processes vitamins and lipids
membrane potential
a difference in electrical potential between the inside and outside of a cell
(singular: meninx) the membranes that cover and protect the central nervous system
an inorganic, elemental molecule that carries out important roles in the body
myelin sheath
a cellular extension containing a fatty substance produced by glia that surrounds and insulates axons
the long cylindrical structures that lie parallel to the muscle fiber
the small structures that make up myofibrils
nasal cavity
an opening of the respiratory system to the outside environment
the functional unit of the kidney
a specialized cell that can receive and transmit electrical and chemical signals
occipital lobe
the part of the cerebral cortex that contains visual cortex and processes visual stimuli
open circulatory system
a circulatory system that has the blood mixed with interstitial fluid in the body cavity and directly bathes the organs
oral cavity
the point of entry of food into the digestive system
the mechanism by which water and solute concentrations are maintained at desired levels
osmotic balance
the appropriate values of water and solute concentrations for a healthy organism
a gland that secretes digestive juices
the organ located between the stomach and the small intestine that contains exocrine and endocrine cells
parasympathetic nervous system
the division of autonomic nervous system that regulates visceral functions during relaxation
parathyroid gland
the gland located on the surface of the thyroid that produces parathyroid hormone
parietal lobe
the part of the cerebral cortex involved in processing touch and the sense of the body in space
pectoral girdle
the bones that transmit the force generated by the upper limbs to the axial skeleton
pelvic girdle
the bones that transmit the force generated by the lower limbs to the axial skeleton
an enzyme found in the stomach whose main role is protein digestion
peripheral nervous system (PNS)
the nervous system that serves as the connection between the central nervous system and the rest of the body; consists of the autonomic nervous system and the sensory-somatic nervous system
wave-like movements of muscle tissue
the throat
pituitary gland
the endocrine gland located at the base of the brain composed of an anterior and posterior region; also called hypophysis
primary bronchus
(also, main bronchus) a region of the airway within the lung that attaches to the trachea and bifurcates to form the bronchioles
pulmonary circulation
the flow of blood away from the heart through the lungs where oxygenation occurs and then back to the heart
the area of the body where feces is stored until elimination
renal artery
the artery that delivers blood to the kidney
renal vein
the vein that drains blood from the kidney
salivary gland
one of three pairs of exocrine glands in the mammalian mouth that secretes saliva, a mix of watery mucus and enzymes
the plasma membrane of a skeletal muscle fiber
the functional unit of skeletal muscle
sensory-somatic nervous system
the system of sensory and motor nerves
set point
the target value of a physiological state in homeostasis
skeletal muscle tissue
forms skeletal muscles, which attach to bones and control locomotion and any movement that can be consciously controlled
the bone that supports the structures of the face and protects the brain
small intestine
the organ where digestion of protein, fats, and carbohydrates is completed
smooth muscle tissue
the muscle that occurs in the walls of hollow organs such as the intestines, stomach, and urinary bladder, and around passages such as the respiratory tract and blood vessels
spinal cord
a thick fiber bundle that connects the brain with peripheral nerves; transmits sensory and motor information; contains neurons that control motor reflexes
a saclike organ containing acidic digestive juices
superior vena cava
the major vein of the body returning blood from the upper part of the body to the right atrium
sympathetic nervous system
the division of autonomic nervous system activated during stressful "fight-or-flight” situations
a junction between two neurons where neuronal signals are communicated
synaptic cleft
a space between the presynaptic and postsynaptic membranes
synovial joints
the only joints that have a space between the adjoining bones
systemic circulation
the flow of blood away from the heart to the brain, liver, kidneys, stomach, and other organs, the limbs, and the muscles of the body, and then back to the heart
the contraction phase of cardiac cycle when the ventricles are pumping blood into the arteries
temporal lobe
the part of the cerebral cortex that processes auditory input; parts of the temporal lobe are involved in speech, memory, and emotion processing
the brain area that relays sensory information to the cortex
thoracic cage
(also, ribcage) the skeleton of the chest, which consists of the ribs, thoracic vertebrae, sternum, and costal cartilages
threshold of excitation
the level of depolarization needed for an action potential to fire
the gland located behind the sternum that produces thymosin hormones that contribute to the development of the immune system
thyroid gland
an endocrine gland located in the neck that produces thyroid hormones thyroxine and triiodothyronine
the cartilaginous tube that transports air from the throat to the lungs
tricuspid valve
a one-way opening between the atrium and the ventricle in the right side of the heart
an increase in the number of hormone receptors in response to increased hormone levels
the urine-bearing tubes coming out of the kidney
the tube that conducts urine from the urinary bladder to the external environment
urinary bladder
the structure that the ureters empty the urine into
a blood vessel that brings blood back to the heart
(of the heart) a large chamber of the heart that pumps blood into arteries
vertebral column
(also, spine) the column that surrounds and protects the spinal cord, supports the head, and acts as an attachment point for ribs and muscles of the back and neck
an organic substance necessary in small amounts to sustain life
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