Weekly Year 1: Physiology Exam - August 7, 2026 (Section...

Question 1

Which of the following is NOT a function of the nervous system?

Accepted Answer

Digesting food — While the nervous system influences digestion through the autonomic nervous system, the primary function of digestion lies within the gastrointestinal system. The nervous system's core functions involve sensory input, motor output, integration, and cognitive processes.

Question 2

What is the primary barrier between the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The vertebral column — The CNS and PNS are functionally and anatomically distinct divisions of the nervous system. While protective layers like meninges and the blood-brain barrier are crucial for CNS protection, there isn't a single 'barrier' separating the CNS from the PNS in the way the question implies. Instead, it's a matter of organizational and anatomical demarcation.

Question 3

The network of neurons and supporting cells found within the gastrointestinal tract is known as the:

Accepted Answer

Enteric nervous system — The enteric nervous system (ENS) is an intrinsic component of the gastrointestinal tract, often referred to as the 'second brain' due to its extensive network of neurons and ability to regulate gut functions independently.

Question 4

How many major divisions does the nervous system have?

Accepted Answer

Two — The nervous system is broadly divided into two main divisions: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

Question 5

The output signal of a nerve cell (neuron) is transmitted through the:

Accepted Answer

Axon — The axon hillock is where the action potential is generated, and the signal then travels down the axon to the synaptic terminals, which are the output sites. The question asks for the output of the nerve cell, which is ultimately transmitted via the axon and released at the synaptic terminal.

Question 6

The primary input zone of a nerve cell (neuron) is typically the:

Accepted Answer

Dendrites — Dendrites are the branched extensions of a neuron that receive signals from other neurons. The cell body also receives input, but dendrites are the primary specialized structures for input.

Question 7

Which of the following is NOT a function of glial cells in the nervous system?

Accepted Answer

Directly transmitting electrical signals — Glial cells provide essential support and protection, but they do not directly transmit electrical signals (action potentials) in the way neurons do. Their roles are primarily supportive, metabolic, and immune-related.

Question 8

For the sense of taste, the primary sensory receptors are located in the:

Accepted Answer

Taste buds — Taste buds, located primarily on the tongue, house the gustatory receptor cells responsible for detecting tastes.

Question 9

Which of the following is NOT a characteristic of life?

Accepted Answer

Randomness — While biological processes can exhibit variation, 'randomness' is not a fundamental defining characteristic of life in the same way that metabolism, reproduction, growth, and responsiveness are.

Question 10

What is the most essential characteristic for an entity to be termed 'living'?

Accepted Answer

Metabolism — While metabolism is crucial, the ability to maintain an organized structure and internal processes that are distinct from the environment is a foundational aspect of life, encompassing aspects of metabolism and response.

Question 11

The maintenance of a stable internal environment within physiological limits is termed:

Accepted Answer

Homeostasis — Homeostasis is the biological term for the ability of an organism to maintain a stable internal environment despite external changes.

Question 12

Which statement best describes the 'internal environment'?

Accepted Answer

The fluid environment outside of cells, but within the organism — The internal environment, in a physiological context, refers to the extracellular fluid (ECF) that surrounds the cells of the body, including plasma and interstitial fluid. It's the immediate milieu in which cells function.

Question 13

Which of the following causes indirect inhibition at synapses?

Accepted Answer

Increased release of excitatory neurotransmitters — Activation of G protein-coupled receptors that lead to the opening of potassium channels (an efflux of positive charge) or the closing of sodium channels (preventing influx of positive charge) can hyperpolarize the postsynaptic membrane, leading to indirect inhibition.

Question 14

Which statement is TRUE about the development of immune cells?

Accepted Answer

All immune cells develop from a single type of stem cell in the bone marrow. — All hematopoietic cells, including immune cells, originate from pluripotent hematopoietic stem cells (HSCs) in the bone marrow. While maturation sites vary (T cells in thymus, B cells in bone marrow), their origin is common.

Question 15

Which of the following is an immune privileged site?

Accepted Answer

Brain — The brain, eyes, and testes are considered immune privileged sites because they have mechanisms to limit immune responses, preventing damage to these vital organs from inflammation and immune cell infiltration.

Question 16

Which of the following is NOT an integrative function of neuronal synapses?

Accepted Answer

Direct transmission of electrical current — Chemical synapses, the most common type, involve the release of neurotransmitters and are not direct electrical conductors like electrical synapses. Signal amplification, filtering, plasticity, and summation are all integrative functions.

Question 17

Which type of sensation is MOST affected in lesions of the sensory cortex?

Accepted Answer

Touch (discriminative) — The sensory cortex is primarily responsible for the conscious perception and discrimination of tactile information, including fine touch, pressure, and texture. Lesions here significantly impair these abilities.

Question 18

The figure showing the weight distribution of 21 subjects suggests:

Accepted Answer

The presence of outliers. — A box plot visually represents data distribution, quartiles, and potential outliers. The whiskers and the isolated points at the extremes (around 45 and 143) indicate the presence of data points that are significantly different from the majority.

Question 19

Intrafusal fibers are:

Accepted Answer

Specialized muscle fibers within muscle spindles. — Intrafusal fibers are specialized muscle fibers that are located within the muscle spindle, a sensory receptor organ that detects changes in muscle length.

Question 20

Sensory receptors are classified functionally based on:

Accepted Answer

The type of stimulus they detect. — Sensory receptors are primarily classified by the type of stimulus they are sensitive to (e.g., photoreceptors, mechanoreceptors, chemoreceptors, thermoreceptors, nociceptors).

Question 21

Which channel membrane protein is specifically important in the process of neurotransmitter release?

Accepted Answer

Voltage-gated Ca2+ channels — The influx of calcium ions (Ca2+) into the presynaptic terminal, mediated by voltage-gated Ca2+ channels, is the critical trigger for the fusion of synaptic vesicles with the presynaptic membrane and the subsequent release of neurotransmitters.

Question 22

The Golgi tendon organ:

Accepted Answer

Detects muscle tension. — The Golgi tendon organ is a sensory receptor located in the tendons of muscles, which is sensitive to muscle tension. It plays a role in regulating muscle force.

Question 23

Nitric oxide produces many of its physiologic effects by stimulating the synthesis of:

Accepted Answer

Cyclic GMP (cGMP) — Nitric oxide (NO) is a signaling molecule that activates guanylate cyclase, an enzyme that catalyzes the production of cyclic guanosine monophosphate (cGMP) from GTP. cGMP then acts as a second messenger.

Question 24

Parasympathetic tone is primarily responsible for:

Accepted Answer

Stimulating digestion — Parasympathetic stimulation promotes 'rest and digest' functions, including increased activity of the gastrointestinal tract, slowing of the heart rate, and constriction of pupils.

Question 25

Skeletal muscle is described by all of the following EXCEPT:

Accepted Answer

Involuntary control — Skeletal muscle is characterized by voluntary control, striated appearance, multinucleation, and attachment to bones. Involuntary control is characteristic of smooth and cardiac muscle.

Question 26

Sympathetic tone serves the following autonomic functions:

Accepted Answer

Increasing alertness, preparing for 'fight or flight' — Sympathetic tone is associated with the 'fight or flight' response, increasing alertness, heart rate, blood pressure, and preparing the body for exertion. The other options describe parasympathetic functions.

Question 27

All of the following ascending sensory pathways are located in the dorsal column EXCEPT:

Accepted Answer

Spinothalamic tract (lateral and anterior) — The spinothalamic tract (both lateral and anterior) is located in the anterolateral part of the spinal cord, carrying pain, temperature, and crude touch sensations. The dorsal columns carry fine touch, vibration, and proprioception.

Question 28

It is correct to say:

Accepted Answer

A reflex arc can involve the spinal cord. — A reflex arc is the neural pathway that mediates a reflex action. It can be as simple as a monosynaptic reflex arc involving a sensory neuron synapsing directly with a motor neuron (e.g., stretch reflex), or it can involve interneurons and higher CNS centers.

Question 29

Integration of autonomic functions involves the following higher centers EXCEPT:

Accepted Answer

Cerebellum — The cerebellum is primarily involved in motor coordination, balance, and fine-tuning of movement. The hypothalamus, brainstem, cerebral cortex, and limbic system all play significant roles in regulating and integrating autonomic functions.

Question 30

When comparing contractile responses in smooth and skeletal muscle, which of the following is MOST different?

Accepted Answer

Speed of contraction and relaxation — Skeletal muscle contracts and relaxes much more rapidly than smooth muscle. While both use actin and myosin, require ATP, can generate action potentials (though smooth muscle can do so differently), and respond to nervous stimulation, their contraction kinetics are vastly different.

Question 31

The cerebellum receives input from the following sites EXCEPT:

Accepted Answer

Vestibular apparatus — The cerebellum receives extensive sensory and motor information from the cerebral cortex, spinal cord, and brainstem nuclei (e.g., vestibular nuclei). The olfactory bulb's primary connections are with other olfactory processing areas, not directly with the cerebellum for motor control.

Question 32

Which of the following structures is a component of a reflex arc?

Accepted Answer

Sensory receptor — A reflex arc typically includes a sensory receptor, an afferent (sensory) neuron, one or more interneurons (association neurons) in the CNS, an efferent (motor) neuron, and an effector (muscle or gland). While not all reflexes involve all these components explicitly (e.g., monosynaptic reflexes omit interneurons, and the brain might not be directly involved in simple reflexes), these are the typical components.

Question 33

Sensory systems code for the following attributes of a stimulus EXCEPT:

Accepted Answer

Location — Sensory systems code for the basic physical attributes of a stimulus: its type (modality), how strong it is (intensity), how long it lasts (duration), and where it is located (location). Emotional valence, while influenced by sensory input, is a higher-level cognitive and emotional interpretation, not a direct coding attribute of the initial stimulus.

Question 34

About acetylcholine, all the following statements are true EXCEPT:

Accepted Answer

It is always excitatory. — Acetylcholine can be excitatory (e.g., at the neuromuscular junction) or inhibitory (e.g., at certain cardiac synapses), depending on the type of receptor it binds to.

Question 35

Sensory receptors are classified functionally according to the following criteria, except:

Accepted Answer

The location in the body. — Sensory receptors are primarily classified by the type of stimulus they respond to (e.g., photoreceptors, mechanoreceptors, chemoreceptors) and their functional properties (e.g., adaptation rate). Their exact location or tissue type is descriptive but not the primary functional classification criterion. Connection to the cerebral cortex relates to processing, not receptor function itself.

Question 36

A specific stimulus produces a receptor potential by:

Accepted Answer

Enhancing Na+ influx into the receptor. — Stimulation of most sensory receptors leads to a change in their membrane potential (receptor potential), often by opening ion channels (like Na+ channels) that increase the influx of positive ions, causing depolarization.

Question 37

The following is FALSE: Detection of the stimulus modality depends upon:

Accepted Answer

The intensity of the stimulus. — The modality of a stimulus (e.g., light, sound, touch) is primarily determined by the type of receptor that is activated and the specific neural pathway and cortical area it projects to. Intensity and duration affect the magnitude and frequency of the signal, not its fundamental modality.

Question 38

The brain interprets signals from the eye as light even if the eye is actually being stimulated by something else, such as pressure. This best describes:

Accepted Answer

Law of Specific Nerve Energies — The Law of Specific Nerve Energies states that the quality of sensation (e.g., light, sound, pain) is determined by the specific nerve pathway stimulated, not by the nature of the stimulus itself. If pressure stimulates the optic nerve, the brain interprets it as light.

Question 39

The two-point touch threshold test serves as a demonstration of:

Accepted Answer

Receptive field size and density of touch receptors — The two-point touch threshold is the minimum distance at which two points of touch can be felt as separate. It varies across the body and reflects the size of the receptive fields of touch receptors and the density of their innervation. Smaller thresholds indicate smaller receptive fields and higher receptor density.

Question 40

The following statements are true of synaptic transmission EXCEPT:

Accepted Answer

It is always excitatory. — Synaptic transmission can be excitatory or inhibitory, depending on the neurotransmitter and the type of receptor on the postsynaptic neuron.

Question 41

With regards to a chemical synapse, the following is true EXCEPT:

Accepted Answer

It involves direct electrical coupling between neurons. — Chemical synapses involve the release and binding of chemical messengers (neurotransmitters), not direct electrical coupling, which is characteristic of electrical synapses. Synaptic delay is inherent to the chemical transmission process.

Question 42

In the synthesis of neurotransmitters, the following is true EXCEPT:

Accepted Answer

Neuropeptides are synthesized as propeptides in the cell body. — Small molecule neurotransmitters are synthesized in the axon terminal. Neuropeptides are synthesized in the cell body and processed through the Golgi apparatus and endoplasmic reticulum before being transported to the axon terminal.

Question 43

The following statement are true of packaging and release of neurotransmitter EXCEPT:

Accepted Answer

Vesicle fusion with the presynaptic membrane is an active process requiring ATP. — While vesicle fusion is an active process, the primary trigger and mediator of neurotransmitter release is the influx of calcium ions. ATP is involved in vesicular transport and recycling, but calcium influx is the immediate cause of exocytosis.

Question 44

With regard to receptors in chemical synaptic transmission, the following is true EXCEPT:

Accepted Answer

Receptor binding always causes depolarization of the postsynaptic membrane. — Receptor binding can lead to either depolarization (excitatory postsynaptic potential, EPSP) or hyperpolarization (inhibitory postsynaptic potential, IPSP), depending on the type of ion channel opened or the signaling cascade initiated.

Question 45

Which of the following statements correctly refers to parasympathetic neurons:

Accepted Answer

They originate from cranial nerves and the sacral region of the spinal cord. — Parasympathetic neurons originate from cranial nerves (III, VII, IX, X) and the sacral spinal cord (S2-S4). Their preganglionic fibers are long, and postganglionic fibers are short. They release acetylcholine at the effector organ.

Question 46

Which list of neurons below are NOT cholinergic?

Accepted Answer

Postganglionic sympathetic neurons innervating sweat glands — Somatic motor neurons, preganglionic sympathetic neurons, and postganglionic parasympathetic neurons all release acetylcholine (cholinergic). Postganglionic sympathetic neurons primarily release norepinephrine (adrenergic), except for those innervating sweat glands, which are cholinergic.

Question 47

In adaptive control, what is NOT true?

Accepted Answer

The controlled system may proliferate. — While adaptive control involves adjustments to external influences and can lead to changes like 'effects of disuse', the controlled system itself doesn't typically 'proliferate' as a direct outcome of adaptive control. Proliferation is a biological growth process, not a control system parameter.

Question 48

Body fluid compartments include:

Accepted Answer

Intracellular fluid, plasma, and interstitial fluid. — The body's water is distributed into two main compartments: intracellular fluid (ICF) within cells, and extracellular fluid (ECF) outside cells. The ECF is further divided into plasma (within blood vessels) and interstitial fluid (surrounding cells).

Question 49

The following single-cell forms are able to carry out de novo synthesis of nutrients from raw materials:

Accepted Answer

Most bacteria and archaea — Many bacteria and archaea are autotrophs, meaning they can synthesize their own organic compounds from inorganic sources through processes like photosynthesis or chemosynthesis. Human cells are heterotrophs and require pre-formed nutrients from their environment.

Question 50

What is NOT true about nucleoli?

Accepted Answer

They are membrane-bound organelles. — Nucleoli are dense structures within the nucleus that are responsible for ribosome biogenesis, including the synthesis of ribosomal RNA (rRNA) and the assembly of ribosomal subunits. However, they are not membrane-bound organelles.

Weekly Year 1: Physiology Exam - August 7, 2026 (Section...

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