Physiology Study Guide Exam 1 PDF

Preview

Summary

Download Physiology Study Guide Exam 1 PDF

Description

Physiology Study Guide- Exam 1 What to study with:  Pre-lab questions  The reading: anything italicized and bolded  No need to memorize anatomical structures via pictures  Study the procedure  Discussion questions Lab Exercise 1: Sensory System- General Senses Pre-Lab 1. General senses include all of the following except: vision. 2. Thermoreceptors are associated with temperature changes. 3. When receptors are continuously stimulated, the sensations may fade away; this phenomenon is known as adaptation. 4. Encapsulated nerve endings include tactile corpuscles. 5. A lamellated corpuscle is stimulated by deep pressure. 6. Free nerve endings function as pain, warm and cold receptors. True. 7. Lamellated corpuscles are located in the epidermis of the skin. False. 

 



  

General senses: touch, pressure, temperature, pain, and senses of muscle movement and body positions. Sensory receptors for these are found in skin, muscles, joints and visceral organs. Nocioreceptors: pain receptors that respond to tissue trauma. Characterized by free nerve endings for pain. Can also be stimulated by extreme hot or cold temperatures. Thermoreceptors: receptors associated with temperature change. Free endings for both warm and cold temperature. Different nerve endings for each. There are two types of thermoreceptors- warm and cold. Mechanoreceptors: receptors associated with touch, stretch, vibration and pressure. Receptors are encapsulated tactile (Meissner’s) corpuscle and encapsulated lamellated (Pacinian) corpuscle. Receptors for special senses are more confined to the head. Sensory adaption: a sensation may fade away when receptors are continuously stimulated. However, this is not as prevalent when it comes to pain. Two-point threshold: the smallest separation of two separate but adjacent points of stimulation on the skin that produces two distinct impressions of touch.

Part A 1. Whenever tissues are damaged, nocioreceptors are likely to be stimulated. 2. Receptors that are sensitive to temperature changes are called thermoreceptors.

3. A sensation may seem to fade away when receptors are continuously stimulated as a result of sensory adaptation. 4. Tactile (Meissner’s) corpuscles are responsible for the sense of light touch. 5. Lamellated (Pacinian) corpuscles are responsible for the sense of deep pressure. 6. Warm receptors are most sensitive to temperatures between 25C/77F and 45C/113F 7. Cold receptors are most sensitive to temperatures between 10C/50F and 20C/68F. 8. Widely distributed sensory receptors throughout the body are associated with general senses in contrast to special senses. Discussion Questions 1. Diabetic Neuropathy: increased blood glucose levels leads to damage of the extremities, most commonly the hands and feet. This damage can lead to tingling, numbness, and decreased touch perception. Typically leads to foot ulcers as diabetics are unable to feel or view wounds due to their location. 2. Brain Injury & Touch Disorders: Injuries to the somatosensory cortex (integration of all touch info) decreases sensory perception of touch. In addition, damage to the parietal lobe or ascending pathways can cause tough disorders. 3. Spinal Cord Injury & Touch Disorders: Spinal cord injury can result in a loss of nerve endings, leading to the inability to recognize touch, pain or temperature. Can cause touch disorders due to the deficits of the somatosensory perception because of Central Nervous System damage. 4. Anaphaia vs. Dysesthesia vs. Hypoesthesia vs. Hyperesthesia: a. Anaphia: full/parietal absence of sense of touch. b. Dysesthesia: Abnormal touch sensations. c. Hypothesia: decreased sense of touch. d. Hyperthesia: increased sense of touch and other stimuli. Lab Exercise 2A: Smell and Taste 1. Receptor cells for taste are located on the tongue, oral cavity and pharynx. 2. The primary olfactory interpretation center is located in the temporal lobe of the cerebrum. 3. Which of the following is not considered a recognized taste? Mint. 4. Taste interpretation occurs in the insula of the cerebrum. 5. Sour sensations are produced from acids. 6. The facial, glossopharyngeal and vagus cranial nerves conduct impulses from taste receptors to the brain. True. 7. Olfactory nerves are located in the foramina of the inferior nasal concha. False. 

Olfaction and taste are dependent on modified sensory neurons called chemoreceptors. Chemicals are considered odorless and tasteless if receptor cells for them are absent.

         

Olfactory receptor cells are neurons surrounded by pseudostratified columnar epithelial cells, called supporting cells. Their apical (near the apex) ends are covered in cilia (olfactory hairs) and are embedded in the mucous of the superior nasal cavity. Olfactory Nerve: Cranial nerve I. Made of olfactory neurons. The primary olfactory cortex is located in the temporal lobe of the cerebrum. Taste receptor cells are located in taste buds on the tongue but also are distributed in other areas of the oral cavity and pharynx. Taste buds: contains taste cells, basal cells and supporting cells. Five recognized categories of taste: sweet (sugars), salt (ionized inorganic salts), sour (acids), bitter (alkaloids) and umami (aspartic and glutamic acids). Facial nerve (cranial nerve VII) conducts sensory impulses from the anterior two thirds of the tongue. Glossopharyngeal nerve (cranial nerve IX) conducts sensory impulses from the poster tongue. Vagus nerve (cranial nerve X) conducts sensory impulses from the pharyngeal region. Sensory information continues through the medulla oblongata and the thalamus to the insula of the cerebrum, which serves as the primary gustatory cortex for taste perception.

Part A: Assessments 1. The distal ends of the olfactory neurons are covered with hair-like cilia. 2. Before gaseous substances can stimulate the olfactory receptors, they must be dissolved in mucus that surrounds the cilia. 3. The axons of olfactory receptors pass through small openings in the cribriform plate of the ethmoid bone. 4. The primary olfactory cortex for interpreting smell is located in the temporal lobe of the cerebrum. 5. Olfactory sensations usually fade rapidly as a result of sensory adaption. 6. A chemical would be considered odorless if a person lacks a particular receptor site on the cilia of the olfactory neurons. Part C 1. 2. 3. 4. 5. 6. 7. 8.

Taste is interpreted in the insula of the cerebrum. The opening to a taste bud is called a taste pore. The taste hairs of a taste cells are its sensitive part. The facial, glossopharyngeal and vagus cranial nerves conduct impulses related to the sense of taste. Substances that stimulate taste cells bind with receptor sites on the surfaces of taste hairs. Sour receptors are mainly stimulated by acids. Salt receptors are mainly stimulated by ionized organic salts. Alkaloids usually have a bitter taste.

Discussion Questions 1. Anosmia vs. Phantosmia vs Parosmia a. Anosmia: partial/total inability to smell. b. Phantosmia: smelling an odor that is not actually there, aka “olfactory hallucination.” c. Parosmia: the brain perceives the scent as something different than it actually is, and this is due to brain dysfunction. 2. Synesthesia: Where the stimulation of one sense ends up stimulating another unrelated sense involuntarily. 3. Differentiate Dysgeusia vs. Ageusia vs. Hypogeusia vs. Hypogeusia. a. Dysgeusia: unpleasant/altered taste sensation. b. Ageusia: complete lack of taste. c. Hypogeusia: reduced ability to taste. d. Hypogeusia: increased ability to taste. 4. Brain and Spinal cord injuries and its associated with smell and taste disorders are due to the damage to the facial, glossopharyngeal and vagus nerves as well as the insula and temporal lobe. Damage to these structures can lead to taste and smell disorders. Lab Exercise 2B: Eye Structure; Visual Tests and Demonstrations Pre-Lab The cornea and the sclera compose the outer layer. We are able to see color because the eye contains cones. The perception of vision occurs in the occipital lobe of the cerebrum. Which of the following is not a part of the middle eye layer? The conjunctiva. The area of our eye where visual acuity is best is the fovea centralis. Which of the following extrinsic skeletal muscles rotates the eyeball superiorly and medially? Superior rectus. 7. The conjunctiva covers the superficial surface of the cornea. False. 8. Tears from the lacrimal gland eventually flow through a nasolacrimal duct into the nasal cavity. True. 1. 2. 3. 4. 5. 6.

     

Eyelid/palpebra: anterior protection of eyes. Conjunctiva: a mucous membrane. Tarsal glands: secrete oily lubricant. Orbicularis oculi: closes eyelids. Levator palebrae superioris: elevates upper eyelid. Lacrimal apparatus o Lacrimal gland: secretes tears. o Lacrimal puncta: two small pores into canaliculi.



 





o Canaliculi: passageways to lacrimal sac. o Canaliculi: passageways to lacrial sac. o Lacrimal sac: collects tears from canaliculi. o Nasolacrimal duct: damage to nasal cavity. Extrinsic muscles o superior rectus o inferior rectus o medial rectus o lateral rectus o superior oblique o inferior oblique Trochlea (pulley): fibrocartilage ring for superior oblique muscle. Outer (fibrous) layer (tunic): o Sclera: white protective layer of dense fibrous connective tissue. o Cornea: transparent anterior portion continuous with sclera. Middle (vascular) layer (tunic): o Choroid: rich blood vessel area; contains melanocytes. o Ciliary body: thickest part of middle layer  Ciliary processes: secrete aqueous humor.  Ciliary muscles: change lens shape.  Suspensory ligaments: hold lens in position. o Iris: smooth muscles change pupil diameter. o Pupil: opening in center of iris allowing light passages. Inner layer (tunic) o Retina: sensory layer with rods and cones.  Macula lutea: high cone density area.  Fovea centralis: area of best visual acuity.  Optic disc: location where optic nerve leaves eye.  Orra serrata: serrated anterior margin of sensory retina.  Optic nerve: contains sensory neurons. o Lens: transparent, focuses light onto retina. o Anterior cavity: contains aqueous humor.  Anterior chamber: between cornea and iris.  Posterior chamber: between iris and lens.  Aqueous humor: clear, watery fluid that fills the anterior and posterior chambers and pupil. o Posterior cavity: contains vitreous humor- a transparent, gel-like filler.

Part A: Assessments a. Aqueous Humor: fills the anterior and posterior chambers of the anterior cavity of the eye. b. Choroid: posterior five-sixths of middle (vascular) layer.

c. d. e. f. g. h. i. j. k.

Ciliary muscles: cause lens to change shape. Conjunctiva: the inner lining of the eyelid. Cornea: transparent anterior portion of outer layer. Iris: smooth muscle that controls the pupil size and light entering the eye. Lacrimal gland: secretes tears. Optic disc: area where the optic nerve exits the eye. Retina: contains photoreceptor cells called rods and cones. Suspensory ligament: connects the lens to the ciliary body. Vitreous humor: fills the posterior cavity of the eye.



List the structures and fluids through which light passes as it travels from the cornea to the retina: o Cornea (aqueous humor)  pupil  lens (vitreous humor)  retina List three ways in which rods and cones differ in structure or function. o Rods see in dim light, cones see in bright light. o Cones let us see color, and there are three types of red, blue and green sensitivity. o Rods are slender and rod shaped, cones are short and conical.



Pre-Lab Part 2: 1. 2. 3. 4. 5. 6. 7. 8.

As a person ages, the elasticity of the lens decreases. Visual acuity is measured using a Snellen eye chart. Color blindness is a characteristic in 7% of males. The blind spot is located at the optic disc of the eye. Astigmatism results from a defect in the curvature of the cornea or lens. Only males can inherit the color blindness condition. False. Nearsightedness is called myopia. A convex lens can be used to correct hyperropia. True.

    

Nearsightedness: myopia. Farsightedness: hyperopia. Astigmatism: defect due to unequal curvatures of the cornea or lens. Visual acuity test: measures the sharpness of vision using a Snellen eye chart. What is 20/10 vision? This means you can see at 20 feet what a normal person can see at 10 feet. Astigmatism test: use the astigmatism chart on the wall and look to see which lines appear more focused. Accommodation test: accommodation is the changing of the shape of the lens that occurs when the normal eye is focused for close vision. Involves a reflex in which the ciliary body is stimulated to contract, releasing tension on the suspensory ligaments and allowing the capsule to become more spherical/convex at near vision. Presbyopia: ability to accommodate decreases with age because the involved tissues lose their elasticity.

 



   

The near point of accommodation increases with age. There are no photoreceptors in the optic disc and it is commonly referred to as the blind spot. Accommodation pupillary reflex: the pupil constricts as a normal accommodation reflex response to focus on close objects and reduces peripheral light. Convergence reflex: the eyes converge as a normal response to focusing on close objects. This orients the eyeballs to the object so the image falls on the fovea centralis of both eyes.

Discussion Questions 1. Cataract: Clouding of the normally clear lens of the eye. The main symptom is blurry vision. 2. Glaucoma: occurs when there is increased fluid buildup within the anterior chamber of the eye. This cause increased pressure in the eye that eventually damages structures such as the optic nerve. This can lead to blindness. 3. Retinal detachment: where the retina detaches from its bottom layer. Symptoms include floaters and shadows in peripheral vision. 4. Diabetic retinopathy: an increased blood sugar damages vessels of color sensitive tissue. Lab Exercise 2C: Electrooculogram   

   

Suspensory ligaments: attaches the lens to the ciliary muscle. When the ciliary muscle contracts, it reduces tension on the suspensory ligament. This allows the lens to thicken and focus on nearby objects. The opposite is true. Retina contains a layer of two kinds of light sensitive photoreceptors, cones and rods. Cones are for day vision and color vision. Rods are used for dim light vision and movement detection in the dark. Rods are concentrated in the periphery of the retina. Visual fixation is where the eye uses muscular control to keep the image on the fovea. This is done by voluntary fixation and involuntary fixation. The eye focuses by changing the shape of the lens from convex to concave, and vice versa. Saccade: rapid movement of eye between fixation points.

Lab Exercise 2D: Ear and Hearing; Ear and Equilibrium Pre-Lab Part 1 1. Hearing is interpreted in the temporal lobe of the cerebrum. 2. Sound loudness is measured in decibels. 3. The middle ear bones articulate from the tympanic membrane to oval window in the sequence of the malleus, incus and stapes.

4. The Rinne test is done to assess possible conduction deafness by comparing bone and air conduction. 5. The cochlea is part of the inner ear. 6. The pharyngotympanic tube connects the outer ear to the inner ear. False. 7. The cochlear nerve serves as the hearing branch of the vestibulocochlear nerve. True. 8. Endolymph is located within the cochlear duct of the cochlea. True. Pre-Lab Part 2 1. The sense organs associated with equilibrium are in the inner ear. 2. The vestibulocochlear nerve conducts impulses associated with equilibrium. 3. Hair cell receptors associated with dynamic equilibrium are located within the crista ampullaris. 4. Otoliths are composed of calcium carbonate. 5. Otoliths are not associated with rotational movement. 6. Eye twitching movements characteristic during rotational movements are called nystagmus. True. 7. Ototliths are located within the semicircular ducts of the inner ear. False.  

Romberg test: evaluates how the organs of static equilibrium in the vestibule enable one to maintain balance. Barany test: evaluates the effects of rotational acceleration on the semeicircular ducts and dynamic equilibrium.

Part B: Assessments 1. The organs of static equilibrium are located within two expanded chambers called the utricle and the saccule. 2. All of the balance organs are found within the temporal bone of the skull. 3. Otoliths are small grains composed of calcium carbonate. 4. Sensory impulses travel from the organs of equilibrium to the brain on vestibular neurons of the vesetibulocochlear nerve. 5. The sensory organ of a semicircular duct lies within a small elevation called the ampulla. 6. The cupula of this sensory organ consists of a dome-shaped gelatinous cap. 7. The vestibular cortex in the cerebellum of the brain processes awareness of body position and movement. Part C: Equilibrium Assessments 1. When the eyes are open, what sensory organs provide information needed to maintain equilibrium? Eyes, inner ears and proprioceptors. 2. When the eyes are closed, what sensory organs provide such information? Only inner ears and proprioceptors.

Discussion Questions 1. Tinnitus: ringing or buzzing in one or both ears. It can be constant or intermittent. This is caused by hearing loss, due to the damaged hairs of the cochlea, or due to brain tumors or emotional stress. Tinnitus is a symptom, not a disease. 2. Meniere’s Disease: Inner ear disorder that causes episodic vertigo. It can cause tinnitus or hearing loss. 3. Differentiate Conduction Deafness: an issue with how sound waves meets the ear. This is located in the outer or middle ear and can be due to wax or water buildup. Sensorineural deafness: damage to inner ear or nerve due to trauma, tumor or infection. Can also be genetic. You can see cochlear hair damage. 4. Otitis: inflammation of inner or middle or outer ear due to infection. Otitis media: infection of air filled space behind the eardrum (the middle ear). 5. Benign Paroxysmal Positional Vertigo (BPPV): Sudden sensation that you’re spinning, or that the inside of your head is spinning. Episodic minor BPPV can be caused by certain movement, trauma or aege. The mechanism of BPPV is due to a loose and calcified otolith in the inner ear. Lab Exercise 3A: Nervous Tissue and Nerves

Pre-Lab 1. The cell body of a neuron contains the nucleus. 2. A multipolar neuron contains many dendrites and one axon. 3. Neuroglia that produce myelin insulation in the Central Nervous System are called oligodendrocytes. 4. The Peripheral Nervous System contains 12 pairs of cranial nerves and 31 pairs of spinal nerves. 5. Schwann cells have a myelin sheath as well as neurilemma 6. A multipolar neuron is the most common structural neuron in both the brain and spinal cord. 7. FALSE: sensory neurons conduct impulses from the spinal cord to a muscle or a gland. 8. TRUE: Astrocytes have contacts between blood vessels and neurons in the Central Nervous System. 9. Axon: also called the nerve fiber- conducts the impulse away from the cell body. Made of an axon, myelin sheath of a Schwann cell, the neurilemma of the Schwann cell, and a node of Ranvier, a narrow gap between Schwann cells. Various Neuronal Structures Multipolar Neuron

Cell body with one axon and multiple dendrites.

Most common neuron in the brain and spinal cord.

Bipolar Neuron

Cell body with one axon and one dendrite.

Located in the receptor parts of the eyes, nose, and ears. Typically rare.

Unipolar Neuron

Cell body with a single process that divides into two branches and functions as an axon. The only dendrites are the receptor ends of the peripheral (distal) process.

Most sensory neurons are unipolar neurons.

Various Neuronal Functions Sensory...