(BRIEFER VERSION) Intermediate Human Physiology: Homeostasis, Cell Biology, Membrane Transport, Nervous System & Synapses

DR. MENG WANG

The study of biological function and how the body works is called __________.

physiology

Research studying the effects of a chemical on cells in a culture dish is conducted __________.

in vitro

Studies conducted in living creatures, such as rats and mice, are performed __________.

in vivo

Drug clinical trials that test side effects, dosage, and rates of passage on healthy human volunteers are classified as __________ clinical trials.

Phase I

Drug clinical trials conducted on a large number of people of both sexes, varied age groups, and multiple health conditions prior to FDA approval are __________ clinical trials.

Phase III

The type of muscle tissue that is voluntary and under conscious control is __________.

skeletal muscle

The muscle tissue found in the walls of hollow organs such as the digestive tract and blood vessels is __________.

smooth muscle

Epithelial membranes that consist of a single layer of cells specialized for the transport of substances are classified as __________ epithelium.

simple

The largest organ in the human body is the __________.

skin

The human body contains a total of __________ interrelated organ systems.

$$11$$

Extracellular fluid consists of $20\%$ blood plasma and $80\%$ __________.

interstitial fluid

Most controlled variables in the body, such as blood pressure and blood glucose, are regulated by __________ feedback systems.

negative

Sensory receptors located in carotid sinuses and the aortic arch that detect blood pressure changes are called __________.

baroreceptors

A homeostatic control mechanism that strengthens or reinforces a change in a controlled variable until an external event stops it is a __________ feedback system.

positive

The constant lateral movement of proteins and phospholipids within the plasma membrane is described by the __________ model.

fluid mosaic

An integral membrane protein that recognizes a specific ligand, such as antidiuretic hormone, is a __________.

receptor

Cell identity markers that distinguish your cells from anyone else's belong to a class of proteins called __________ proteins.

major histocompatibility

The process by which cells like neutrophils and macrophages extend pseudopods to engulf bacteria or dead cells is called __________.

phagocytosis

The non-specific cellular uptake of extracellular fluid droplets through inward pouching of the plasma membrane is __________.

pinocytosis

The process by which the Golgi apparatus packages proteins into vesicles that fuse with the plasma membrane to release contents outside the cell is __________.

exocytosis

The thinnest elements of the cytoskeleton, composed of actin and located mostly at the edge of the cell, are __________.

microfilaments

Folds in the plasma membrane that increase surface area for rapid diffusion and chemical reactions are called __________.

microvilli

Motile cilia and flagella both exhibit a characteristic __________ arrangement of microtubules.

$$9+2$$

The only cell type in the human body that possesses a flagellum is the __________.

sperm

The inner membrane of a mitochondrion is folded into structures called __________ to increase surface area for metabolic reactions.

cristae

Mitochondrial DNA is inherited exclusively from the __________.

mother

The granular endoplasmic reticulum that functions in protein synthesis and secretion is also known as __________ ER.

rough

Structures in the cytosol responsible for degrading unwanted or damaged proteins are called __________.

proteasomes

In the human body, approximately __________ of total body water is located inside cells within the intracellular compartment.

$$67\%$$

The extracellular compartment contains approximately __________ of total body water.

$$33\%$$

Movement of molecules against their concentration gradient requiring ATP and specific carrier pumps is termed __________.

active transport

The simple diffusion of water across a selectively permeable membrane is known as __________.

osmosis

Water channels in the plasma membrane that facilitate osmosis are called __________.

aquaporins

Pure water has an osmotic pressure of __________.

$$0$$

A $1\,\text{M}$ solution of $\text{NaCl}$ dissociates in water to yield a concentration of __________ Osm.

$$2$$

Normal blood plasma has an osmolarity of approximately __________ mOsm.

$$300$$

When a red blood cell is placed in a hypertonic solution, water leaves the cell causing it to shrivel up and __________.

crenate

The glucose carrier isoform found in adipose tissue and skeletal muscle that is inserted into the plasma membrane upon stimulation is __________.

GLUT4

The primary active transport pump $\text{Na}^+/\text{K}^+$ ATPase pumps __________ $\text{Na}^+$ ions out of the cell for every 2 $\text{K}^+$ ions pumped in.

$$3$$

The $\text{Na}^+/\text{K}^+$ ATPase pump moves __________ $\text{K}^+$ ions into the cell for every 3 $\text{Na}^+$ ions moved out.

$$2$$

Transport that relies on the sodium concentration gradient established by primary active pumps to move another molecule uphill is called __________.

secondary active transport

Secondary active transport in which the transported substance moves in the same direction as sodium is called cotransport or __________.

symport

The brain and spinal cord together comprise the __________ nervous system.

central

A grouping of neuron cell bodies located outside the central nervous system is called a __________.

ganglion

A bundle of axons located within the central nervous system is called a __________.

tract

Sensory neurons that feature a single short process branching like a T into two longer processes are classified structurally as __________.

pseudounipolar

The most common structural classification of neurons, possessing several dendrites and one axon, is __________.

multipolar

Efferent neurons responsible for reflex and voluntary control of skeletal muscles are __________ motor neurons.

somatic

In the peripheral nervous system, myelin sheaths around axons are formed by __________.

Schwann cells

In the central nervous system, myelin sheaths around central axons are formed by __________.

oligodendrocytes

Glial cells in the central nervous system that cover capillaries and induce the blood-brain barrier are __________.

astrocytes

The epithelial lining of brain ventricles and the central canal of the spinal cord is formed by __________.

ependymal cells

At rest, neurons maintain a resting membrane potential of __________ mV.

$$-70$$

Voltage-gated $\text{Na}^+$ channels open when the axon membrane potential depolarizes to a threshold of __________ mV.

$$-55$$

During an action potential, voltage-gated $\text{Na}^+$ channels become inactivated when the membrane potential reaches __________ mV.

$$+30$$

The period during an action potential when $\text{Na}^+$ channels are inactive and no stimulus can excite the neuron is the __________ refractory period.

absolute

The most common structural type of synapse between two neurons is an __________ synapse.

axodendritic

When an action potential arrives at the terminal bouton, it opens voltage-gated __________ channels to trigger neurotransmitter release.

$$\text{Ca}^{2+}$$

The protein complex that docks synaptic vesicles to the presynaptic terminal membrane is the __________ complex.

SNARE

When $\text{Ca}^{2+}$ enters the presynaptic terminal, it binds to the sensor protein __________ to stimulate vesicle fusion.

synaptotagmin

A graded depolarization of the postsynaptic membrane caused by opening $\text{Na}^+$ or $\text{Ca}^{2+}$ channels is an __________.

excitatory postsynaptic potential

A graded hyperpolarization of the postsynaptic membrane caused by opening $\text{K}^+$ or $\text{Cl}^-$ channels is an __________.

inhibitory postsynaptic potential

Acetylcholine receptors that are ligand-gated ion channels found at the neuromuscular junction are __________ ACh receptors.

nicotinic

Acetylcholine receptors that are G-protein coupled channels found on smooth and cardiac muscle are __________ ACh receptors.

muscarinic

Opening a nicotinic acetylcholine receptor channel requires the binding of __________ acetylcholine molecules.

$$2$$

Effects of acetylcholine on nicotinic receptors are inhibited by the drug __________, but not by tetrodotoxin.

curare

The enzyme present in the synaptic cleft that inactivates acetylcholine by hydrolyzing it into acetate and choline is __________.

acetylcholinesterase

In heart pacemaker cells, binding of acetylcholine to muscarinic receptors releases the __________ G-protein subunit complex to open $\text{K}^+$ channels.

beta-gamma

The primary excitatory neurotransmitter in the brain, utilized in $80\%$ of cerebral cortex synapses, is __________.

glutamate

The primary inhibitory neurotransmitter in the brain, which acts by opening $\text{Cl}^-$ channels, is __________.

GABA