Exam 3 Study Guide Material Flashcards
Label the different portions of the spine using APR module 5.
C,T,L,S,C
Label the different components of the spinal nerve. Including dorsal rootlets, root, and ganglion as well as ventral rootlets, root, and spinal nerve.
Ventral= front of body
Dorsal= back of body
Identify the phrenic nerve which is a deep branch of the cervical plexus.
Identify different dorsal and ventral ramus as well as gray and white ramus.
The ventral ramus is the anterior division of the spinal cord that supplies anterolateral parts of the trunk and limbs. The dorsal ramus contains nerves the serve the dorsal portion of the truck.
Identify keys points of the brainstem including the diencephalon, pons, midbrain, and medulla oblongata.
The Pons kind of looks like the letter P while the diencephalon looks like a sideways D.
Identify the different ventricles within the brain. Including lateral, third, and fourth ventricles. Remember the ventricles in the brain contain CSF that cushion and protect the brain.
Identify the fifth cranial nerve called the trigeminal nerve. Remember that this nerve is the largest of the cranial nerves. Its primary function is to provide sensory innervation to the face and is divided into three main branches. The different branches are the ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves.
Mixed nerve for sensation of the face and control of chewing movement.
Identify the seventh cranial nerve called the facial nerve. Remember this carries nerve fibers that control facial movement and expression.
Identify the different components of the inner ear including the tympanic membrane and cavity, cochlea, and vestibulocochlear nerve.
Identify the different components of the eyeball including the sclera, cornea, pupil, lens, and suspensory ligaments.
What makes up the CNS and the PNS?
CNS- brain and spinal cord
PNS- everything else like nerves and ganglia (examples include cranial nerves, spinal nerves and their roots and branches, peripheral nerves, and neuromuscular junctions)
What are the important features of a typical neuron (include Nissl bodies, myelin, conductivity, and NTs)?
Conductivity- neurons respond to stimuli by producing electrical signals.
NTs- neurons secrete NTs when an electrical signal reaches the end of the nerve fiber that passes a message to other cells.
Nissl bodies- compartmentalized rough ER. They can synthesize proteins within the neuron.
Myelin- analogous to insulation on a wire. Made by oligodendrocytes in the CNS and Schwann cells in the PNS. Myelin consists of the plasma membrane of glial cells and lipids. Myelinated portions of the axon are called internodes and are separated by gaps called nodes of Ranvier. In the PNS, the myelin sheath is called the neurilemma. Fibrous CT called endoneurium surrounds it and is essential for the regeneration of damaged fibers. (CNS nerve fibers are incapable of regeneration!!)
What are the 5 kinds of neuroglia found in the CNS and PNS and what are their functions?
CNS- Oligodendrocytes, Ependymal cells, Microglia, and Astrocytes
PNS- Schwann and Satellite cells
Identify the upper and lower motor neurons as well as their location and functions.
Ascending tracts carry sensory info up the cord whereas descending tracts carry motor impulses down the brainstem and spinal cord. Several tracts undergo decussation meaning they cross over the other side of body at the brainstem or spinal cord.
Descending tracts typically have two neurons involved; an upper neuron with its soma in the cerebral cortex or brainstem, and a lower motor neuron in the brainstem or the spinal cord whose axon leads to a muscle or different effector.
What are the divisions of the spinal cord?
The spinal cord is divided into the cervical, thoracic, lumbar, sacral, and coccygeal regions.
What is the difference between afferent and efferent fibers?
Afferent fibers carry sensory signals from receptors to the CNS.
Efferent fibers carry motor signals from the CNS to effectors.
What are the contents of the central canal of the spinal cord?
The right and left sides of central gray matter are connected by gray commissure. In the middle of the gray commissure is the central canal.
Remember gray matter contains somas, dendrites, and proximal parts of axons. White matter consists of myelinated axons organized into bundles.
The central canal contains CSF!
Describe the structure of a nerve including the three layers of CT surrounding them.
A nerve is several axons wrapped by connective tissue in the PNS. The endoneurium surrounds one axon. The perineurium wraps a fascicle of axons. The epineurium covers the entire nerve.
What are the three meninges layers associated with the spinal cord?
The outermost layer is the dura mater. It provides a protective sheath around nervous tissue.
The space in between the dura mater and bone is called the epidural space and is filled with BVs, adipose tissue, and loose CT.
The arachnoid mater is a spider-web-like structure that adheres to the dural sheath. It consists of simple squamous epithelium and collagenous and elastic fibers.
The pia mater is a thin and translucent membrane that adheres to the spinal cord.
Which part of the nervous system controls the movement of your hand?
The median nerve (C8) of the brachial plexus. This is part of the PNS motor division called the somatic motor division.
Describe first through third-order neurons.
Sensory signals traveling up the cord typically travel across three neurons from their origin in receptors to their destination in sensory areas of the brain. A first order neuron detects the stimulus and transmits the signal to the spinal cord or brainstem; a second-order neuron neuron continues to the thalamus of the brain; a third-order neuron carries the signal to the sensory region of the motor cortex.
What is decussation in the ascending tracts?
The medial lemniscus pathway decussates in the medulla.
The spinothalamic pathways decussates in the spinal cord.
You step on a sharp pin, what pathway does the pain signal follow?
The spinothalamic tract ascends in the anterior and lateral funiculi to end in the thalamus. This tract decussates in the spinal cord.
What are the general characteristics of a reflex?
Properties of somatic reflexes include quickness, involuntary, and stereotyped. They are quick since they involve few interneurons. They are involuntary as they occur without thought. Stereotyped meaning the response is the same every time.
How do visceral reflexes differ from somatic reflexes?
Visceral reflexes are unconscious automatic, stereotyped responses of visceral effectors to stimuli. An example is a rise in blood pressure triggers reflexive decrease in heart rate. Visceral reflexes are controlled by the ANS and act on glands, cardiac muscle, cardiac muscle, and smooth muscle.
Somatic reflexes are controlled by the somatic nervous system and rely on simple neural pathway called a reflex arc. Somatic reflexes, for instance, involve a direct connection from the ventral horn of the spinal cord to the skeletal muscle.
What are the components of the reflex arc?
The autonomic activity involves a reflex arc that requires several components including receptors, afferent neurons leading to CNS, efferent neurons, and effectors.
First somatic receptors in skin, muscle, or tendons, sense heat, pain, stretch, etc. Second, afferent nerve fibers carry information from the receptors into the dorsal horn of spinal cord. Third, an integrating center in the spinal cord or brainstem processes the information and determines whether an efferent neuron will issue a command to muscle. Efferent nerve fibers carry motor impulses to muscle and finally skeletal muscles carry out a response. The afferent neuron synapses directly with an efferent neuron.
Identify the 5 plexuses of spinal nerves including the name, location, nerves that arise from it, and the structures innervated by it.
All plexuses receive fibers from anterior rami and give rise to peripheral nerves.
- Cervical plexus
- Brachial plexus
- Lumbar plexus
- Sacral plexus
- Coccygeal plexus
Identify the location, nerves that arise from it, and structures innervated by the Cervical plexus.
- Arises from the ventral rami of nerves C1 to C5 (neck).
- Gives rise to the phrenic nerves.
- Phrenic nerves supply the diaphragm and plays an essential role in breathing.
Identify the location, nerves that arise from it, and structures innervated by the Brachial plexus.
- Arise from the ventral rami of nerves C4 through T2. (shoulder)
- Nerves that arise from the brachial plexus include musculocutaneous, axillary, radial, median, and ulnar.
- All of these nerves supply upper limb while the radial nerve supplies the muscle and skin of posterior arm and forearm and the musculocutaneous supplies the muscles of anterior arm and skin.
Identify the location, nerves that arise from it, and structures innervated by the Lumbar plexus.
- Arise from ventral rami of nerves L1 and L4 with some fibers from T12. (lower back)
- The femoral nerve is an important nerve that arises from this.
- The femoral nerve supplies the quad femoris, sartorius, and iliopsoas and other muscles and skin of the thigh.
Identify the location, nerves that arise from it, and structures innervated by the sacral and coccygeal plexuses.
- Sacral plexus is formed from ventral rami L4, L5, and S1 and S4. Coccygeal lexus is formed from ventral rami of S4, S5, and Co1.
- The sacral plexus gives off the sciatic nerve which is a combo of tibial and common fibular nerves. The coccygeal plexus gives rise to anococcygeal nerve.
What is the location and function of the medulla oblongata? Important anatomical markings.
Has a prominent pair of ridges on ventral surface that look like pyramids.
Gives rise to cranial nerves IX, X, and XII
There are cardiac centers that control BP and flow. Respiratory centers regulate rate and depth of breathing. Nuclei present with gagging, vomiting, coughing, sneezing, salivation, and sweating. Sensory and motor functions for head and neck.
What is the location and function of the pons? Important anatomical markings.
Has a bulge on front portion and peduncles that attach to cerebellum posteriorly.
Origins of cranial nerves V-VII and some VIII. Functions in facial sensation and expression, control of chewing, respiration, and sleep.
What is the location and function of the midbrain? Important anatomical markings.
Has a tectum which is a roof-like structure dorsal to cerebral aqueduct. It has 4 bulges.
Gives rise to cranial nerves 3 and 4.
Red nucleus and substantia nigra for motor control. Superior colliculus for visual attention and inferior colliculus for auditory attention.
What is the location and function of the substantia nigra? Important anatomical markings.
Substantia nigra is a motor center that relays inhibitory signals to the thalamus and basal nuclei of the cerebrum with the effect of suppressing unwanted motor contractions.
What is the limbic system and its functions?
The limbic system is a ring of structures on the medial side of each cerebral hemisphere that encircles the corpus callosum and thalamus. Plays a critical role in emotions and learning. Functions in learning, emotion, gratification, and aversion responses. It includes structures like cingulate gyrus, hippocampus, amygdala, hypothalamus, thalamus, basal nuclei, and prefrontal cortex.
What is the location and general function and organization of the hypothalamus?
Hypothalamus forms part of the wall and floor of the third ventricle. Has several key functions and key role in maintaining homeostasis.
1. Major integrating center for ANS
2. Monitors blood temperature.
3. Drives to eat and drink.
4. Regulates waking and falling asleep. Nuclei for circadian rhythm.
5.Hormone secretion of oxytocin and ADH
6. wide range of emotions including sex drive, copulation, and orgasm.
7. Mammillary bodies between hippocampus and hypothalamus needed for new memory formation.
What is the somatosensory organization of the postcentral gyrus and its location?
The thalamus routes all somesthetic/ general signals to the postcentral gyrus of the parietal lobe.
Where is Wernicke’s area in the cerebrum and what is its function?
It is posterior to the lateral sulcus of left brain. Functions in the recognition of written and spoken language. Wernicke’s area is a sensory association area that transmits plans of speech to Broca’s area. Located in the superior temporal gyrus.
Where is Broca’s area in the cerebrum and what is its function?
This is inferior to the prefrontal cortex of the left brain. Functions in speech by generating the motor plan for muscles of the larynx, lips, and more. Plan is transferred to the primary motor cortex for execution.
What is the location and function of the corpus callosum and thalamus?
The corpus callosum connects the two hemispheres so both sides of the brain can communicate with each other.
The thalamus is a large ovoid mass that makes up 4/5ths of the diencephalon. Called the gateway to cerebral cortex. Involved in sensation, movement, memory, and emotion. It is the relay station of sensory signals to the cerebrum.
What are the differences between the autonomic/visceral and somatic nervous system?
The ANS has involuntary control of glands, cardiac muscle, and smooth muscle. ANS is responsible for visceral reflexes. The ANS adjust the function of visceral effectors rather than providing initial stimulus. NOT independent ONLY motor pathways.
The somatic nervous system involves skeletal muscles and is voluntary. Involves sensory and motor pathways.
Describe the two-neural pathway of autonomic output.
The ANS requires two neurons to reach a target. The preganglionic neuron has its soma in the brainstem or spinal cord. The axon (preganglionic fiber) terminates in the autonomic ganglion where it synapses with a postganglionic neuron whose axon (postganglionic fiber) extends the rest of the way to the target cells.
What is the role of the adrenal medulla and its hormones in the sympathetic nervous system?
The adrenal medulla is the inner part of the adrenal gland that secretes epinephrine and NE. The adrenal medulla is a modified sympathetic ganglion. Some sympathetic fibers terminate on modified postganglionic cells in the medulla. When stimulated, the medulla secretes E and NE into the blood.
Where are taste buds located?
The tongue has the most taste buds but some are present in the soft palate, pharynx, epiglottis, and checks. Projections on the tongue called lingual papillae are associated with tastes. The fungiform papillae are mushroom-shaped on tp and sides of the tongue with 3 taste buds. Vallate papillae are large pumps in the back tongue that contain around 1/2 of all taste buds.
Which nerve endings are found in the skin?
What are the muscles in the eyes involved in looking up and down?
Upward- superior rectus
Downward- inferior rectus
lateral- lateral rectus
Medial- medial rectus
What is the structure of rods and cone cells?
Rods- night vision with the pigment rhodopsin. The rods have an outer segment that has a stack of membranous discs enclosed in a plasma membrane. Each disk is studded with the pigment rhodopsin.
Cones- highly concentrated in the fovea. Day vision and fine-resolution detailed images. The outer segment tapers to a point and the discs are parallel infolding not separate discs.
Describe the anatomy of the cochlea.
The cochlea is a spiral organ composed of hair cells and supporting cells. The hair cells have stiff microvilli on top called stereocilia. It is filled with fluid and plays a vital role in the sense of hearing. The cochlear duct, the organ of hearing, is inside the cochlea. Inside the cochlea, there are three fluid-filled spaces separated by membranes.
What are the semicircular ducts in the ear?
The semicircular ducts are filled with endolymph. Each duct opens into the utricle and has a dilated sac at one end called an ampulla. Within the ampulla are hair and supporting cells. A gelatinous membrane called a cupola extends to the roof of the ampulla. When the body accelerates, the duct rotates but the endolymph lags behind and pushes the cupola. This bends the stereocilia on the cupola and stimulates hair cells. This is how semicircular ducts detect acceleration.
What is the difference between linear and angular acceleration? What inner-ear structure is specialized to detect this?
Angular acceleration is the change in rate of rotation and is detected by semicircular ducts. Linear acceleration is perceived by saccule and utricle.
Receptors for equilibrium, coordination, and balance make up the vestibular apparatus and include the 3 semicircular ducts, 2 chambers, the saccule, and the utricle.
What is the fovea and macula lutea of the eye?
The Macula lutea is near the optic disc and is a dense path of receptors for detailed vision. In the center of the macula lutea is the fovea which is the portion of the retina where the most detailed images are produced.
What are the two major divisions of the true spinal nerve once it exits the intervertebral foramen?
Dorsal ramus and ventral ramus
Which region in this diagram represents the location of the olfactory mucosa?
B
Which location marked on the diagram would you always expect to find a taste bud?
B- circumvallate papilla
Which of the structures in this diagram represent the semicircular canals?
D
The sclera of the eyeball is represented by which label on this diagram?
C
