1. BIOL 2401
Fundamentals of Anatomy and Physiology Mrs. Willie Grant (210)
Chapter 17:
The Special Senses
Chapter 18:
The Endocrine System

2. An Introduction to the Special Senses
Learning Outcomes
17-1 Describe the sensory organs of smell, trace the olfactory pathways to their destinations in the brain, and explain the physiological basis of olfactory discrimination.
17-2 Describe the sensory organs of taste, trace the gustatory pathways to their destinations in the brain, and explain the physiological basis of gustatory discrimination.
17-3 Identify the internal and accessory structures of the eye, and explain the functions of each.
17-4 Explain color and depth perception, describe how light stimulates the production of nerve impulses, and trace the visual pathways to their destinations in the brain.
17-5 Describe the structures of the external, middle, and internal ear, explain their roles in equilibrium and hearing, and trace the pathways for equilibrium and hearing to their destinations in the brain.

3. An Introduction to the Endocrine System
Learning Outcomes
18-1 Explain the importance of intercellular communication, describe the mechanisms involved, and compare the modes of intercellular communication that occur in the endocrine and nervous systems.
18-2 Compare the cellular components of the endocrine system with those of other systems, contrast the major structural classes of hormones, and explain the general mechanisms of hormonal action on target organs.
18-3 Describe the location, hormones, and functions of the pituitary gland, and discuss the effects of abnormal pituitary hormone production.
18-4 Describe the location, hormones, and functions of the thyroid gland, and discuss the effects of abnormal thyroid hormone production.
18-5 Describe the location, hormone, and functions of the parathyroid glands, and discuss the effects of abnormal parathyroid hormone production.

4. An Introduction to the Special Senses
Five Special Senses
Olfaction
Gustation
Vision
Equilibrium
Hearing

5. Figure 17-1a The Olfactory Organs
Olfactory Pathway to the Cerebrum
Olfactory epithelium
Olfactory nerve fibers (N I)
Olfactory bulb
Olfactory tract
Central nervous system
Smell (Olfaction)
Olfaction Organs provide sense of smell. They are located in nasal cavity.
1 What is the life-span of an olfactory receptor?
Cribriform plate
Superior nasal concha
The olfactory organ on the left side of the nasal septum 5

6. 17-2 Taste (Gustation)
Taste Buds—associated with epithelial projections (lingual papillae) on superior surface of the tongue
Three Types of Lingual Papillae
Filiform papillae Fungiform papillae Circumvallate papillae

7. Figure 17-4a External Features and Accessory Structures of the Eye
(Vision)
Accessory Structures of the Eye (provide protection, lubrication and support)
Include: The palpebrae (eyelids) and the lacrimal apparatus
The palpebrae (eyelids)
The lacrimal apparatus
Eyelashes
Pupil
Lateral canthus
Palpebra
Sclera
Palpebral fissure
Medial canthus
Lacrimal caruncle
Corneal limbus
Gross and superficial anatomy of the accessory structures 7

9. Muscles of the Eye

10. 17-3 The Eye
Eyeball
Is hollow and divided into two cavities
Large posterior cavity
Smaller anterior cavity

11. Intermediate vascular layer Deep inner layer
17-3 The Eye
Three Layers of the Eye
Outer fibrous layer
Intermediate vascular layer
Deep inner layer
2 What are the components of the fibrous tunic and vascular tunic?

12. Outer layer called pigmented part Inner called neural part (retina)
17-3 The Eye
The Inner Layer
Outer layer called pigmented part Inner called neural part (retina)
Contains visual receptors and associated neurons
Rods and cones are types of photoreceptors
Rods—Do not discriminate light colors/Highly sensitive to light
Cones—Provide color vision
Densely clustered in fovea, at center of macula
3 What the two types of photoreceptors, and how do their functions differ?

13. The Chambers of the Eye
Aqueous Humor
Vitreous boody

14. Light Refraction (bending of light by retina and lens)
The Eye
Accommodation (shape of lens changes to focus image on retina)
Astigmatism
Condition where light passing through cornea and lens is not refracted properly
Visual image is distorted
Visual acuity
Clarity of vision
“Normal” rating is 20/20
Light Refraction (bending of light by retina and lens)

15. 4 What is presbyopia?

16. 17-4 Visual Physiology The Visual Pathways
Begin at photoreceptors and ends at visual cortex of cerebral hemispheres
Message crosses two synapses before it heads toward brain

17. 17-5 The Ear
The External Ear
Auricle—surrounds entrance to external acoustic meatus and protects opening of canal as well as provides directional sensitivity.
External acoustic meatus—ends at tympanic membrane (eardrum)
Tympanic membrane—is a thin, semitransparent sheet that separates external ear from middle ear
Ceruminous glands—Integumentary glands along external acoustic meatus that secretes waxy material (cerumen wich keeps foreign objects out of tympanic membrane and slows growth of microorganisms in external acoustic meatus.

18. 17-5 The Ear
The Middle Ear
Also called tympanic cavity
Communicates with nasopharynx via auditory tube
Permits equalization of pressures on either side of tympanic membrane
Encloses and protects three auditory ossicles
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)

19. 17-5 The Ear
The Internal Ear
Contains fluid called endolymph
Bony labyrinth surrounds and protects membranous labyrinth
Subdivided into:
Vestibule
Semicircular canals
Cochlea

20. Figure 17-21 The Anatomy of the Ear
External Ear
Middle Ear
Internal Ear
Elastic cartilages
Auditory ossicles
Oval window
Semicircular canals
Petrous part of temporal bone
Auricle
Facial nerve (N VII)
Vestibulocochlear nerve (N VIII)
Bony labyrinth of internal ear
Cochlea
Tympanic cavity
Auditory tube
To nasopharynx
External acoustic meatus
Tympanic membrane
Round window
Vestibule
5 What structures separate the middle ear from the internal ear? 20

22. 18
The Endocrine System

23. An Introduction to the Endocrine System
Regulates long-term processes
Growth
Development
Reproduction
Uses chemical messengers to relay information and instructions between cells
6 What is the basic difference between endocrine glands and exocrine glands?

24. 18-2 Hormones
Classes of Hormones
Hormones can be divided into three groups
Amino acid derivatives
Peptide hormones
Lipid derivatives
Secretion and Distribution of Hormones
Hormones circulate freely or travel bound to special carrier proteins

26. 18-2 Structural Classification of Hormones

27. 18-9 Endocrine Tissues of Other Systems
Many Organs of Other Body Systems Have Secondary Endocrine Functions
Intestines (digestive system)
Kidneys (urinary system)
Heart (cardiovascular system)
Thymus (lymphatic system and immunity)
Gonads (reproductive system)

28. 18-10 Hormone Interactions
Hormones Interact to Produce Coordinated Physiological Responses
When a cell receives instructions from two hormones at the same time, four outcomes are possible
Antagonistic effects - opposing
Synergistic effects - additive
Permissive effects - one hormone is necessary for another to produce effect
Integrative effects - hormones produce different and complementary results

29. 18-10 Hormone Interactions
Hormones Important to Growth
Growth hormone (GH)
Thyroid hormones
Insulin
PTH and calcitriol
Reproductive hormones

30. 18-10 Hormone Interactions
The Hormonal Responses to Stress
General Adaptation Syndrome (GAS)
Also called stress response
How body responds to stress-causing factors
Is divided into three phases
Alarm phase
Resistance phase
Exhaustion phase
9 What is the basic difference between the stress response and homeostasis?

31. 18-10 Hormone Interactions
The Effects of Hormones on Behavior
Hormone changes
Can alter intellectual capabilities, memory, learning, and emotional states
Affect behavior when endocrine glands are over-secreting or under-secreting
Aging and Hormone Production
Causes few functional changes
Decline in concentration of:
Growth hormone
Reproductive hormones