Lab 11THE SPECIAL SENSES AND THE ENDOCRINE GLANDS
Lab 11 Activities1. Identify structures of the eye and ear on models and
figures 2. Identify gross structures of the sheep eye3. Identify histological structures of the eye4. Perform tests of visual acuity, near point
accommodation, astigmatism, and blind spot5. Perform fundoscopic and otoscopic exams6. Identify endocrine glands on anatomical models and
know the hormones each secretes and their effects7. Identify endocrine glands, their cells and other
structures visible on microslides (pituitary, thyroid/parathyroid, pancreas, adrenal gland, ovary, and testis and the hormones secreted by each)
The Special Senses• Special Photoreception (sight)
• Special Mechanoreception– Hearing– Static Equilibrium– Dynamic Equilibrium
• Special Chemoreception– Smell (Olfaction)– Taste
Surface Anatomy of the Eye
• Eyebrows divert sweat from the eyes and contribute to facial expressions
• Eyelids (palpebrae) blink to protect the eye from foreign objects and lubricate their surface
• Eyelashes detect and deter foreign objects
Extrinsic Eye Musclessuperior oblique
superior rectuslateral rectus
medial rectus
inferior rectus inferior obliqueOptic nerve
Internal Anatomy of the Eye
Tunics
surface of retina
Macula
Optic disc
Vasculature
Ophthalmoscope of Retina
Organization in the Retina1. Pigmented Layer:
– shields retina from light scattering
2. Neural Layer:– photoreceptors and several types of interneurons
Micrograph of the Retina
Path of Light
Neurons of the Neural Layer• Photoreceptors:
– rods (for dim light)
– cones (3 colors [“blue,” “green” and “red”] for bright light)
• Bipolar cells connect interneurons
Neurons of the Neural Layer• Horizontal Cells
enhance contrast (light versus dark boundaries) and help differentiate colors
• Amacrine cells detect changes in the level of illumination
• Ganglion cells’ axons become the Optic Nerve
Retina 40x
Retina, 100x
Retina, 400x
Fundoscopic ExamWARNING: Do not examine the macula for more than 1 second at a time!•Carefully follow the instructions provided in the lab manual supplement.• There are excellent
demonstrations of this exam– https://www.youtube.com/watch?v=7lhvhK
vK_iM– http://www.ncbi.nlm.nih.gov/books/NBK221
/
You are not required to perform this portion of the lab if you are uncomfortable about it. However, you will still be responsible for knowing the material!
External Ear• Pinna (Auricle):
focuses sound waves• External auditory
canal transmits sound waves• Ceruminous Glands
secrete cerumin (ear wax) to protect external auditory canal
• Tympanic membrane registers sound waves
Middle Ear & Auditory Tube• Three auditory ossicles (bones)
conduct vibrations of tympanic membrane to the oval window of the inner ear
• Pharyngotympanic tube (auditory tube or eustachian tube) connects to pharynx, equalizes air pressure on both side of the tympanic membrane
Middle Ear Ossicles• Malleus (hammer)• Incus (anvil) • Stapes (stirrup)
The Membranous Labyrinth
Otoscopic ExamWARNING: Be careful not to damage the tympanic membrane by inserting the otoscope too far into the ear or by jerking the otoscope!•Carefully follow the instructions provided in the lab manual supplement.• There are excellent demonstrations of
this exam– https://www.youtube.com/watch?v=FE0sot4O
oAE– https://www.youtube.com/watch?v=0BJ2EP3T
acU
You are not required to perform this portion of the lab if you are uncomfortable about it. However, you will still be responsible for knowing the material!
The Endocrine
System
ENDOCRINE GLANDSThe Endocrine Glands Produce Hormones Which Are Secreted Into the Blood Stream In Order To Locate Specific Target Tissues. Target Tissues Have Specific Hormone Receptors. Target Tissues Respond To Hormonal Commands In Specific Ways.
Anterior Lobe =Adenohypophysis
Posterior Lobe =Neurohypophysis
Pituitary Gland, 40x
each cell type secretes a different hormoneeach cell type secretes a different hormone
Hormones of the Pituitary Gland• Anterior Lobe – Adenohypophysis
– growth hormone (hGH)– thyroid stimulating hormone (TSH)– adrenocorticotropic hormone (ACTH)– prolactin– follicle stimulating hormone (FSH)– luteinizing hormone (LH) / interstitial cell stimulating
hormone (ICSH)• Posterior Lobe – Neurohypophysis
– oxytocin– vasopressin = antidiuretic hormone (ADH)
Thyroid Gland
ParathyroidGlands
Thyroid Gland
Trachea
Esophagus
Thyroid Thyroid
Thyroid, 40xThyroid, 40x
Follicles containing colloid (thyroxins)Follicles containing colloid (thyroxins)
Thyroid, 100xThyroid, 100x
Thyroid, 400xThyroid, 400xthyroglobulinthyroglobulin
TT33 = triiodothyronine = triiodothyronineTT44 = tetraiodothyronine = thyroxine = tetraiodothyronine = thyroxine
Secretes calcitonin = thyrocalcitoninSecretes calcitonin = thyrocalcitonin
Thyroid & Parathyroid, 40xThyroid & Parathyroid, 40x
Thyroid & Parathyroid, 100x
Thyroid & Parathyroid, 400x
Parathyroid Hormone = Parathormone
Adrenal Gland, 40x
MedullaMedulla
CortexCortex
CortexCortex CortexCortex
CortexCortex
Adrenal Gland, 40xAdrenal Gland, 40x
cortexcortex
cortexcortex
Medulla: Norepinephrine and
Medulla: Norepinephrine and
Epinephrine (= Adrenalin)
Epinephrine (= Adrenalin)
(mineralocorticoids)(mineralocorticoids)
(glucocorticoids)(glucocorticoids)
(gonadocorticoids)(gonadocorticoids)
Pancreas
Pancreatic tissue, 40xPancreatic tissue, 40x(note Pacinian corpuscle)(note Pacinian corpuscle)
Pancreatic Islets, 100xPancreatic Islets, 100x
Acinar CellsAcinar Cellsendocrineendocrine exocrineexocrine
Pancreatic Islets, 100x(note Pacinian corpuscle)
Pancreatic Islet, 400x
Alpha cells - glucagonAlpha cells - glucagon Beta cells - insulin Beta cells - insulin
Ovary
Ovary, 40xOvary, 40x
Developing follicles Developing follicles secrete mostly secrete mostly estrogens and some estrogens and some progesteroneprogesterone
Ovary, 40xOvary, 40x
corpus luteum secretes mostly progesterone and some estrogen
TestisTestis
TestisTestis
Seminiferous Tubules
epididymis
TestisTestis
Testis
Androgens/Testosterone, etc.
Testis, 400xTestis, 400x
Cow Eye DissectionCow Eye Dissection
End Lab 11 End Lab 11 PresentationPresentation
Thyroid Gland
ThyroidColloid
Pancreas
Endocrine Pancreas
Ovary
Ovary