Nervous System Overview Quiz

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Questions and Answers

Which component is NOT part of the reflex arc?

Synaptic cleft (correct)

Stimulus

Efferent neuron

Receptor

What is the primary function of the myelin sheath?

Receive impulses from dendrites

Transmit sensory signals

Increase conduction speed of impulses (correct)

Facilitate chemical transmission

Which type of reflex is characterized by having two or more synapses?

Polysynaptic reflex (correct)

Monosynaptic reflex

Somatic reflex

Autonomic reflex

The autonomic nervous system is primarily responsible for controlling what?

Involuntary functions Signup and view all the answers

In terms of neuron structure, what role do dendrites play?

Receive impulses towards the cell body Signup and view all the answers

Which of the following accurately describes the function of sensory nervous system?

Relay information from peripheral receptors to CNS Signup and view all the answers

What distinguishes the central nervous system from the peripheral nervous system?

Contains the brain and spinal cord Signup and view all the answers

Which chemical transmitter is predominately involved in autonomic responses?

Acetylcholine Signup and view all the answers

Which nerve primarily stimulates glycogenolysis in the liver?

Greater splanchnic nerve Signup and view all the answers

What role does the lesser splanchnic nerve play in relation to the adrenal medulla?

Facilitates secretion of hormones into blood Signup and view all the answers

Which nerve is responsible for the retention of feces through relaxation of muscles in the distal large intestine?

Lumbar splanchnic nerve Signup and view all the answers

What effect does the sympathetic nervous system have on skeletal muscles during stress responses?

Stimulates glycogenolysis and improves contraction strength Signup and view all the answers

What is one of the effects of the sympathetic nervous system on blood during stress responses?

Enhances clotting ability Signup and view all the answers

Which ganglia do the less splanchnic nerves relay in to control the urinary bladder?

Inferior mesenteric ganglia Signup and view all the answers

In females, the sympathetic nervous system has what kind of effect on the uterine muscles?

Variable effects depending on the menstrual cycle Signup and view all the answers

What is the primary composition of catecholamines secreted by the adrenal medulla?

80% adrenaline & 20% noradrenaline Signup and view all the answers

Which of the following is NOT a function of catecholamines released from the adrenal medulla?

They increase digestion and metabolism. Signup and view all the answers

What is the pathway for preganglionic sympathetic fibers in the sympathetic nervous system?

They leave the spinal cord via the ventral roots. Signup and view all the answers

Which cranial structure is primarily affected by sympathetic innervation from preganglionic neurons of T1 and T2?

Eye Signup and view all the answers

Which of the following best describes the axons of postganglionic neurons in the adrenal medulla?

They have lost their axons. Signup and view all the answers

What effect does sympathetic activation have on the pupils?

Contraction of the dilator pupillae muscle (mydriasis) Signup and view all the answers

Which statement about the transport of catecholamines is true?

They are removed slowly from the blood. Signup and view all the answers

In the sympathetic nervous system, where do preganglionic fibers synapse if they pass through the sympathetic chain without relay?

In collateral ganglia Signup and view all the answers

What is a characteristic role of the sympathetic nervous system in relation to the skin?

Contraction of piloerector muscles Signup and view all the answers

What condition is characterized by miosis, ptosis, anhidrosis, and warm, red skin on the same side as a lesion in the cervical sympathetic chain?

Horner's Syndrome Signup and view all the answers

Which of the following effects is associated with increased cardiac properties due to sympathetic stimulation?

Increased excitability Signup and view all the answers

Which of the following spinal segments are involved in the origin of autonomic nerves to the heart?

T1 to T4 Signup and view all the answers

What is the primary consequence of vagal stimulation of the lungs?

Bronchoconstriction Signup and view all the answers

Which symptom would NOT be expected in Horner's Syndrome?

Increased sweating on the affected side Signup and view all the answers

In terms of the gastrointestinal tract, sympathetic stimulation has what primary effect?

Relaxes smooth muscle of the intestinal wall Signup and view all the answers

Which factor does NOT directly affect cerebral blood flow?

Respiratory rate Signup and view all the answers

What type of effect does sympathetic stimulation have on the coronary vessels?

Mild vasodilation through indirect mechanisms Signup and view all the answers

What component of the autonomic nervous system primarily innervates organs in the abdomen?

Thoracic splanchnic nerves Signup and view all the answers

Which manifestation is associated with increased blood flow to the brain?

Increased mental alertness Signup and view all the answers

What type of fibers are preganglionic fibers described as?

Myelinated Signup and view all the answers

Where are the cell bodies of postganglionic fibers located?

In the autonomic ganglion outside the CNS Signup and view all the answers

What is the ratio of postganglionic fibers to preganglionic fibers?

1:8-9 Signup and view all the answers

Which type of ganglia is NOT associated with the sympathetic chain?

Terminal ganglia Signup and view all the answers

What is a key feature of paravertebral ganglia?

Paired for each segment of the spine Signup and view all the answers

Which of the following statements accurately describes collateral ganglia?

Located midway between the spinal cord and target organs Signup and view all the answers

The function of autonomic ganglia includes which of the following?

To act as distribution centers for signals Signup and view all the answers

Which ganglia are named according to the vessels they are near?

Collateral ganglia Signup and view all the answers

What characterizes the fibers connecting ganglia to organs?

Highly variable in length ranging from 1mm to several cm Signup and view all the answers

What is a characteristic of the fibers in the sympathetic chain?

Postganglionic fibers are unmyelinated Signup and view all the answers

Study Notes

Nervous System

The nervous system receives information from internal and external environments.
It integrates this information (processes it).
Levels of integration include spinal cord reflexes, lower brain (subcortical), and higher brain (cortical) levels (thinking and reasoning).
The system responds rapidly and precisely.

Anatomical Divisions

Central Nervous System (CNS): Brain and spinal cord are the main processing centers.
Peripheral Nervous System: Peripheral nerves and ganglia transmit signals between the CNS and the body.

Neuron

A neuron is the basic structural unit of the nervous system.
It has a cell body containing the nucleus and organelles.
Dendrites receive impulses to the cell body.
The axon (nerve fiber) carries impulses from the cell body.
- Myelinated axons have a myelin sheath for faster conduction.
- Non-myelinated axons do not have a myelin sheath.
A nerve is made up of many nerve fibers (neurons).

Synapse

Synapses are sites where axons of one neuron terminate on dendrites, soma, or axon of another neuron.
The synaptic cleft is the space where chemical transmitters are released at the synaptic site.
Synapses transmit impulses (signals or electrical activity) from one nerve cell to another.

Physiological Divisions

Sensory Nervous System: Transmits information from peripheral receptors to the CNS (through sensory fibers). Enters the spinal cord via the posterior root.
Motor Nervous System: Transmits information from the CNS to the periphery (muscles, glands, others) through motor fibers. Leaves the spinal cord via the anterior root.
Receptors: Receive external information (light, sound, temperature, pressure). Also receive internal information (muscle tension, visceral distention).
- Somatic sensory division receives information from the body surface (skin, muscles, joints), special senses.
- Visceral sensory division receives information from internal organs (viscera).
Somatic Nervous System: Controls skeletal muscles (reflexes or voluntary).
Autonomic Nervous System: Controls involuntary functions including smooth muscle, cardiac muscle, and glands.

Reflex Arc

Components include: Stimulus, Receptor, Afferent neuron (carries signal to CNS), Center (synapse in CNS), Efferent neuron (carries response from CNS to effector), Effector (muscle or gland).
Reflexes, such as the knee-jerk reflex, can be monosynaptic (one synapse) or polysynaptic (more than one synapse).

Autonomic Ganglia

Collections of neurons outside the CNS.
Preganglionic fibers are myelinated.
Postganglionic fibers are unmyelinated. Function as distribution centers for relaying nerve impulses to target organs.
Types: Paravertebral, Collateral, Terminal.

Adrenal Medulla

Modified sympathetic ganglion, supplied by preganglionic fibers.
Secretes catecholamines (adrenaline and noradrenaline) directly into the blood.
Effects last longer than sympathetic stimulation.

Head and Neck Functions

The head and neck have many functions, including pupil constriction, elevation of eyelids, widening of visual field, and contraction of muscles in the skin.

Thorax

Functions include heart rate regulation and lung function, through sympathetic and parasympathetic function.

Abdomen

Functions include regulation of gastrointestinal tract motility and secretion. Also includes liver, spleen, and other organ regulation.

Pelvic Viscera

Functions related to the pelvic organs, including gut function (feces), the urinary bladder (urine), genitalia in males and females. Also includes metabolic processes.

Autonomic Reflexes

Simple reflexes are integrated in the spinal cord (e.g., bladder control).
More complex reflexes integrate at higher CNS levels (e.g., respiration).
Pupillary reflexes are important autonomic functions.

Chemical Transmission

Acetylcholine is used in cholinergic systems.
Noradrenaline/Norepinephrine is used in adrenergic systems.
Both have different receptors and methods of removal from the synapse.

Autonomic Drugs

Drugs can either stimulate or depress (block) parasympathetic or sympathetic activity.
Different types of drugs affect different receptors in the autonomic nervous system.

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Description

Test your knowledge on the structures and functions of the nervous system. This quiz covers the central and peripheral nervous systems, neurons, and the process of information integration. Perfect for students learning about human biology and anatomy.