Nervous System Flashcards
(20 cards)
Refers to the nerve cell.
A) Cell membrane
B) Nucleus
C) Nuclear envelope
D) Neuron
Neuron
The plasma or cell membrane is the outer covering of the cell through which it interacts with the outside environment. It is a lipid bilayer that is composed of cholesterol, phospholipids, and some protein. It functions to control the passage of substances into and out of the cell, enclose the cell and provides a support and barrier to the cell contents, and also plays a role in cell to cell communication.
The nucleus is a large, usually centrally located organelle that serves to have very important functions. It is composed of the nuclear envelope, the chromatin, and the nucleolus. The nucleoli are dense bodies that consist of proteins and ribosomal RNAs. They act as the assembly site for both small and large ribosomal subunits. On the other hand, Chromatin are dispersed, thin strands of DNA, histones, and other proteins that function by regulating protein synthesis and the overall chemical reaction of the cell. DNA is the genetic material of a person. Chromatins condense during cell division to form chromosomes. They are contained in the nucleus of the cell. Lastly, the nuclear envelope is a double membrane that encloses the nucleus and separates it from the cytoplasm. It allows movement of materials in and out of the nucleus.
Neuron refers to the nerve cell and all its processes. They are specialized, excitable cells meaning to say, they have the ability to receive stimuli and conduct nerve impulses. Each neuron is made up of a cell body and its neurites/nerve fibers- the dendrites and axons. Dendrites are those responsible for conducting information toward the cell body while the axon conduct impulses away.
All of the following muscles are innervated by the dorsal scapular nerve, except: A) Rhomboid minor B) Rhomboid major C) Latissimus dorsi D) Levator scapulae
Latissimus dorsi
The Latissimus dorsi is innervated by the thoracodorsal nerve (C6, C7 and C8), and not by the dorsal scapular nerve.
All the other muscles, the levator scapulae, and rhomboids minor and major are innervated by the dorsal scapular nerve (C4, C5).
Which of the following muscles is innervated by both the obturator nerve and the sciatic nerve (tibial portion)?
A) Gracilis
B) Adductor longus
C) Adductor brevis
D) Adductor magnus
Adductor magnus
The muscles of the medial compartment of the thigh include the gracilis, adductor longus, adductor brevis, adductor magnus, and the obturator externus. All of which are innervated by the Obturator nerve which arises from the nerve roots L2, L3 and L4.
However, the adductor magnus receives dual innervation from two nerves. Its adductor portion is innervated by the obturator nerve while its hamstring portion is innervated by the sciatic nerve (tibial portion).
Increased _________ stimulation increases heart rate.
A) Parasympathetic
B) Sympathetic
C) Sensory Efferent Fibers
D) Motor Afferent Fibers
Sympathetic
The sympathetic nervous system is associated with the mobilizations of the “fight-or-flight” response. In general, these situations mean an increase in the body’s heart rate. The parasympathetic nervous system is associated with the “rest and digest”, or “feed and breed” response.
A network of nerves.
A) Nerve plexus
B) Brachial plexus
C) Lumbar plexus
D) Sacral plexus
Nerve plexus
A nerve plexus is a network of intersecting peripheral nerves. This allows redistribution of nerve fibers within the different peripheral nerves. The nerve plexuses of the human body are the cervical and brachial plexus located at the root of the upper limbs and the lumbosacral (lumbar plexus and sacral plexus) plexus located at the root of the lower limb.
Which nerve winds around the structure labeled as #3? A) Sciatic nerve B) Common peroneal nerve C) Tibial nerve D) Femoral nerve
IMAGE
Common peroneal nerve
The common peroneal nerve or common fibular nerve winds around the head of fibula, labeled as #3 in the photo. Originally, the common peroneal nerve and the tibial nerve originate from the large sciatic nerve. Traversing at the back of the thigh, the sciatic nerve divides above the popliteal fossa and give rise to the tibial and common peroneal nerves. The former continues to descend down the posterior thigh and leg then finally divides into the medial and lateral plantar nerves of the foot. The latter however, passes laterally and innervates the short head of the biceps femoris. It continues to pass lateral to the muscle’s tendon, winding to the fibular head and then passing to the tunnel between the fibula and fibularis longus tendon. This anatomical location makes the common peroneal nerve susceptible to crush injuries as it lies just beneath the skin and is very superficial.
The other choices- sciatic nerve, tiibal nerve and femoral nerve do not wind around the head of the fibula.
Contains the brain and spinal cord
A) Endocrine System
B) Peripheral Nervous System
C) Pituitary Gland
D) Central Nervous System
Central Nervous System
The CNS consists of the brain and spinal cord. The PNS does not include the brain and spinal cord.
The longest nerve in the body is the \_\_\_\_\_\_\_\_\_\_\_\_\_ nerve. A) Brachial B) Saphenous C) Sciatic D) Femoral
Sciatic
The sciatic nerve is the longest nerve in humans. It begins in the lower back and runs through the buttock and down the lower limb. It innervates some of the muscles and skin of the thighs, lower legs, and feet. The Great Saphenous is the longest vein and sartorius is the longest muscle.
The brachialis is innervated by which of the following nerves?
A) Ulnar nerve
B) Median nerve
C) Musculocutaneous nerve
D) Radial nerve
Musculocutaneous nerve
The brachialis muscle, an elbow flexor, is innervated by the musculocutaneous nerve (C5, C6).
Choice A. The ulnar nerve arises from the medial cord of the brachial plexus and from the nerve roots C8 and T1. It innervates the medial compartment of the forearm, wrist and hand, as well as the intrinsic muscles. It does not influence the brachialis.
Choice B. The median nerve arises from both the lateral and medial cord of the brachial plexus (C5, C6, C7, C8 and T1). It innervates the lateral compartment of the forearm, wrist and hand which is responsible in flexion and pronation. It does not influence the brachialis.
Choice D. The radial nerve arises from the posterior cord of the brachial plexus and from the nerve roots C5, C6, C7, C8 and T1. It basically innervates the extensor muscles and can be found at the posterior compartment of the arm and forearm. It does not influence the brachialis.
Which of the following is a column of nervous tissue extending from the medulla oblongata to the second lumbar vertebra?
A) brain stem
B) nerve root
C) spinal cord
D) cauda equina
spinal cord
The spinal cord is a bundle of nerve fibers enclosed in the spine. It begins at the medulla oblongata and continues down the spine until the 1st or 2nd lumbar vertebrae. The spinal cord connects parts of the body to the brain. Together, the spinal cord and brain make up the CNS.
Dermatome pertaining to the ulnar side of the ring finger.
A) C5
B) C6
C) C7
D) C8
C8
C5 dermatome refers to the deltoid area, anterior aspect of the entire arm to the base of the thumb.
C6 dermatome refers to the anterior arm, radial side of the hand to the thumb and index finger.
C7 dermatome refers to the lateral arm and forearm to the index, long and ring fingers.
C8 dermatome refers to the medial arm and forearm to the long, ring, and little fingers.
The somatic nervous system consists of nerve fibers that connect the CNS to the ______, Whereas the autonomic nervous system consists of fibers that connect the ______.
A) skin and skeletal muscles; brain to the spinal cord
B) visceral organs; CNS to the skin and skeletal muscles
C) heart and intestines; CNS to the cardiac and smooth muscles
D) skin and skeletal muscles; CNS to the visceral organs
skin and skeletal muscles; CNS to the visceral organs
The somatic nervous system consists of nerve fibers that connect the CNS to the skin and skeletal muscles; whereas the autonomic nervous system consists of fibers that connect the CNS to the cardiac and smooth muscles.
After eating a huge amount of dinner, this would provoke the following reactions, except:
A) Dilation of the eyes
B) Vasodilation of the blood vessels
C) Increased motility of the GI tract
D) Constriction of the lungs
Dilation of the eyes
The parasympathetic system is responsible for the body’s “rest and digest” function hence, after ingestion of a huge amount of meal, it would stimulate the parasympathetic division. This results in constriction of the eyes, stimulation of the salivary glands, decreased heart rate and myocardial contraction, constriction of the lungs, vasodilation of the blood vessels, increased motility of the GI tract, contraction of the detrusor muscle, relaxation of the sphincter, and erection of the genitals.
The question, however, asks for the exemption of function of the parasympathetic division. Meaning to say, it should rule out the sympathetic function which is choice A, the dilation of pupils.
What nerve innervates the PRIMARY hip flexors?
A) Obturator nerve
B) Sciatic Nerve
C) Lateral Femoral cutaneous nerve
D) Femoral nerve
Femoral nerve
The iliopsoas is considered the primary hip flexor(s). The iliopsoas is innervated by the Femoral nerve.
Which of the following innervates the popliteus?
A) 1st and 2nd sacral nerves
B) Tibial nerve
C) Obturator nerve
D) Inferior gluteal nerve
Tibial nerve
The popliteus muscle is considered as a deep muscle of the posterior leg. It is innervated by Tibial nerve (L4, L5, S1). It is known to “unlock” the knee and flexes the leg at the knee joint.
Choice A. The 1st and 2nd sacral nerves innervate the piriformis muscle. The muscle functions to laterally rotate the hip joint.
Choice C. The obturator nerve innervates the muscles of the medial compartment of the thigh, which includes the hip adductors and one lateral rotator, the obturator externus. Among the adductors include the gracilis, adductor longus, adductor brevis, and the adductor magnus wherein its hamstring portion is innervated by the sciatic nerve.
Choice D. The inferior gluteal nerve arises from the nerve roots L5, S1, and S2. It innervates the gluteus maximus.
Forms the myelin sheath of neurites in the central nervous system.
A) Oligodendrocytes
B) Schwann cells
C) Microglia
D) Astrocytes
Oligodendrocytes
Oligodendrocytes are a type of neuroglial cells that form the myelin in the central nervous system CNS. They also influence the biochemistry of neurons. Oligodendrocytes have small bodies, have few delicate processes and no cytoplasmic filaments.
Schwann cells are actually the counterpart of the oligodendrocytes. They are responsible for the production of myelin in the peripheral nervous system (PNS).
Microglia are a type of neuroglial cells that are scattered throughout the CNS. They are basically inactive but when diseases and phagocytosis are present, they proliferate in the CNS and are joined by blood monocytes. Microglia are considered as the smallest neuroglial cells and have wavy branches with spines.
Astrocytes are a kind of neuroglial cells and are of 2 types: the fibrous and protoplasmic. The fibrous astrocytes in particular, have long slender processes yet have small cell bodies. They act as a supporting framework for the neurons and are electrical insulators. The protoplasmic astrocytes on the other hand, still have small cell bodies but have short thick processes. They act as conduit for metabolites or raw materials, participate in glycogen storage, and have phagocytic functions as well.
The femoral nerve arises from L2, L3, and L4 nerve roots. Which of the following muscles is not supplied by the femoral nerve?
A) rectus femoris
B) tensor fascia latae
C) sartorius
D) vastus medialis
tensor fascia latae
The femoral nerve (L2, L3, L4) innervates the Iliacus muscle, Sartorius, Rectus Femoris, and the Pectineus.
The tensor fascia latae, however, is innervated by the superior gluteal nerve which arises from the nerve roots L4, L5, and S1. It acts as a hip abductor, hip flexor, and a weak internal rotator in any position of the hip.
Sympathetic stimulation of the iris causes:
A) corneal constriction
B) pupillary constriction
C) pupillary dilation
D) corneal edema
pupillary dilation
Sympathetic stimulation of the iris causes pupillary dialation.
Parasympathetic stimulation of the iris causes pupillary constriction.
Injury to this nerve will result in an inability to dorsiflex the foot and a mild sensory disturbance between the first and second toes.
A) tibial nerve
B) lateral plantar nerve
C) medial plantar nerve
D) deep peroneal nerve
deep peroneal nerve
Injury to the deep peroneal nerve will result in an inability to dorsiflex the foot and a mild sensory disturbance between the first and second toes. The nerve innervates the tibialis anterior, extensor hallucis longus and brevis, lumbricals, interossei, extensor digitorum brevis, and the peroneus tertius.
The tibial nerve innervates the tibialis posterior, abductor and adductor hallucis, flexor hallucis longus and brevis, flexor digitorum longus and brevis, quadratus plantae, soleus, gastrocnemius, popliteus, and plantaris.
The medial plantar nerve is a branch of the tibial nerve that has cutaneous supply to the medial three and a half digits. It innervates the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and the most medial lumbricals.
The lateral plantar nerve is a branch of the tibial nerve and supplies cutaneously to the lateral one and a half toes. It innervates the muscles not supplied by the medial plantar nerve.
The motor neuron and all the muscle fibers that it controls is called a _________.
A) Neuromuscular junction
B) Synergist
C) Motor unit
D) Endomysium
Motor unit
A motor unit is made up of a motor neuron and the skeletal muscle fibers innervated by that axon.
Choice A. Neuromuscular junction or synapse, is formed by several branches of an axon and a single muscle fiber.
Choice B. A synergist refers to a muscle that works or helps another muscle to cause a movement.
Choice D. Endomysium refers to the connective tissue sheath surrounding a muscle fiber.
