Anatomy & Physiology 2002 Lecture Notes, Directory

These are lecture notes listed in sequence:

001a_Telencephalon.Nov15

001b_Autonomic_NS.Jan11

001c_Autonomic_neurotransmitters.Feb10

001d_Emotions_Memory.Feb11

01_Olfaction_Taste.Jan16

001d_Integration_Emotions.Jan16

02_Eye_Accessory_Structures.Jan16

03_Eye_histology_physiology.Jan16

04_Hearing.Feb12

05.5_Endocrine_Intro.Feb16

05_Balance_Organs.Feb16

06_Pituitary.Feb16

07_Thyroid_Adrenal.Feb2016

08_Pancreas.Mar11

09_Pineal.Feb2016

10_Blood.Feb2016

11_12_Leukocytes.Hemostasis.Feb2016

12_Blood_Clotting.Feb2016

13_Heart.Mar2016

14_Heart_electrical.Mar2016

15_Arteries_and_Veins_Lecture.Mar2016

16_Circulation_Special.Mar2016

17_Lymphatic_Sys.Mar2016

18_Defenses.Mar2016

19_Immunity.Mar2016

20_Respiratory_Sys.Mar2016

21_Respiratory_Physiology.Mar2016

22_Digestive_Sys_to_stomach.29Mar2016

23_Digestive_Sys_Intestines.Mar2016

24_Liver_&_Pancreas.March2016

25_Metabolism_I_catabolism.April2016

26_Metabolism_II_BMR_hunger.11April2016

26a_Nutrition_I_water_soluble.Apr10

26b_Nutrition_II_Oil_Soluble_Sources.Apr10

27_Urinary_System.12April2016

28_Kidney_regulation.12April2016

29_Repro_embryology_spermatogenesis.12April2016

30_Male_reproductive_system.12April2016

31_Female_Repro_Anat.12April2016

32_Female_Hormones.12April2016

33_Development.June09

34_pregnancy_birth.June10

35_Labor_May12

Dissection of the Eye and its Orbit in the Cat

Dissection of  the Eye and its Orbit in the Cat

Follow protocol Notebook Illustrations

The brain should have previously been removed from your cat (see Removal and Study of the Cat Brain). You should identify the upper and lower eyelids, and the nictitating membrane which comes up from below the eye. Note the conjunctival surfaces, and the inferior fornix.

REMOVAL OF THE EYE

lines_to_cut_P2112028lbd

Locate the optic nerves where they enter the cranium through the optic foramina.
Draw lines from each optic nerve to the medial and lateral limits of the orbits.
The accompanying image shows the location of the cut to make.
cuts_in_cranial_floor_P2112029

Cut on these lines with the end of a hack saw. Be certain to cut laterally enough to prevent part of the frontal from overhanging, and all the way to the optic foramina.

lift_cut_triangle_P2112030

lift the triangle Lift off the triangular section of the roof of the orbit, cutting it free from any underlying tissue which may adhere to it, preserving features attached to the eye. Mark the superior-most muscle with an indelible “X” to keep track of it later in the dissection. (Can you find the superior oblique and its trochlea, on the medial superior border of the orbit? This is a challenge.)

05_nictitating_mem_P2112014

Cut the anterior portion of the eye loose from the socket by cutting closely along the bone to free up the eye itself. Lift up the entire structure, cutting any peripheral tissues which may hold it down. After you have lifted it in the front, slide the scalpel under the rear-most portion to free it from the skull. Note that the nictitating membrane marks the inferior portion of the dissected portion.
Note the membrane which surrounds the entire orbit (periorbita). The lacrimal gland is under it on the lateral superior side. Work the periorbita open with a blunt probe, remove the adipose tissue which served as padding. The most superficial superior muscle will be the levator palpebrae superioris, which raises the eyelid. It does not insert into the bulb.

DISSECTION OF THE EYE

The fat has been removed from the excised eye to reveal the muscles (upper picture).
Find the four rectus muscles:
lateral, superior, medial and inferior rectus
Use a blunt probe to free them from the optic nerve. The inferior obliquecrosses over the inferior rectus. The superior oblique should be present, but this dissection may not retain the trochlear loop. Its tendon of insertion is medial to the insertion of the superior rectus. Here is a labeled version of the right hand image. (Do not confuse the deeper four retractor bulbi muscles which are under the rectus muscles.)

Deep to the four rectus muscles (peeled back in this image) are four portions of the retractor bulbi. Note the optic nerve which exits the eye at the center of these four parts. The four retractor bulbi have been reflected to show the rear of the eye ball. The sclera is opalescent bluish white, the optic nerve at the center.

06_cut_P2112015
With the fine scissors, make a small vertical snip through the rear wall of the bulb just medial to the optic nerve (do not squeeze the bulb during this cut…).

07_extend_P2112017

Hold the eye over a petri dish lid, extend the cut (keep it shallow) sagittally through the center of the cornea. Note that aqueous humor drains out as the cornea is being cut.

14_portions_of_eye_P2112026
dissected cross section

As you lift the cut anterior piece, note that the lens is attached to it by suspensory ligaments. Cut through the iris, and lift off the cut portion, cutting its ligaments.

Note that the lens is opaque-white, an artifact of preservation. The posterior cavity is filled with clear jelly-like vitreous humor. Note the three tunics of the wall of the eye:
fibrous tunic (sclera plus cornea)
vascular tunic (iris, ciliary body and choroid)
nervous (retina)
Here is a labeled image of the components of the eye (upper image in left frame).


The retina will appear pearly yellow. Note the optic disk identifiable by the vessels may be seen to emerge from it, and pass under the retina. The fovea centralis will be towards the center and seen as a yellowish depression. (Here is a labeled image.) The retina peels away easily from the underlying choroid. This, a detached retina is a serious condition requiring immediate attention in patients to prevent death of the retina and blindness in the patient.

13_ciliary_processes_P2112025md

In the anterior portion of the eye, note that the lens is supported by suspensory ligaments. Posterior to it is the ruffled surface of the black pigmented ciliary processes which produce the aqueous humor. The ora serrata is the anterior boundary of the retina. The iris is golden on the exterior surface, black on the posterior. The cornea is tough and relatively thick.

Make three illustrations:
1) Cuts made to remove eye
2) muscles teased out
3) cross section of the eye

Nystagmus Demonstration

Nystagmus Demonstration

A visual reflex mediated by semicircular cancals

Tracking objects is a complex activity under normal circumstances, but the complexity is markedly increased during movement of the head. There is a system within the brain located in the superior colliculi which receives information on rotation of the head from the semicircular canals. The superior colliculi then directs eye movements via the extrinsic muscles of the eye to compensate for these head movements.

The effects of this system can be seen when it over compensates from prolonged rotation of the body. The semicircular canals become accommodated to the rotation, and when the rotation is halted, the endolymph continues to move, triggering impulses interpreted in the superior colliculi as strong rotational acceleration signals. It therefore directs the compensating jerking of the eyes called nystagmus (from the Greek, meaning to nod). Nystagmus may also be a sign of malfunction in one of the stages of the system responsible for this reflex.
ANATOMY OF THE EXTERNAL EYE:

Eye_external_features

Familiarize your self with the external features of the eye:

Medial and lateral canthus (corners of the eye
Caruncle (little mound of flesh in the medial canthus. Can you spot the tiny puncti?)
Superior and inferior palpebrae (eyelids)
Conjunctiva (covers the sclera)
Iris and pupil

NYSTAGMUS DEMONSTRATION

1. Place student on rotating stool, away from all furniture, sharp corners, etc.
2. Rotate student a determined number of times (5, 10, 15, etc) Take care to stop before nausea is induced…
3. Stop rotation abruptly with subject’s eyes facing observers so that the eyes may be observed at close range (about a foot away).
4. Observe the following:
a) Is the movement large or small
b) How frequent is the movement (jerks/second or second between jerks)
c) How long do the movements persist.

Does the strength or persistence relate to the length of time rotation was performed?
Is there a minimum length of time in order to accommodate to the rotation?
Use of a video camera with slow motion playback may allow this reflex to be quantified.

Histology of the Eye

Histology of the Eye

Follow protocol Notebook Illustrations

This is another slide in which, because of the size of the specimen, you will have to move around to see the entire structure, even at the lowest power. First look at the slide with the naked eye to orient yourself to its gross features: you should be able to see the cornea, lens (often fragmented on the interior), cavities, and ciliary bodies. Note that some slides are oriented R and L, others up and down…

With the 4x objective, find the sclera and follow it around the entire perimeter, identifying the regions as you come to them and noting the layers in each region. Again, identify all features listed before you begin an illustration. You will make three illustrations:

  1. The gross anatomy of the anterior portion
  2. A low power view of the rear wall
  3. A high power view of the retina:

Slide 8:  Eye, Monkey, general structure, sagittal section, general features H 1064  (MF 4th, page 343, 345)

Eyeball_PC271488
Section through the eye optic nerve on the left,25x

At 25x: Gross anatomy of section through the eye:    (Here is a labeled version of the eye section.)
FIBROUS TUNIC
cornea (anterior 1/6th)
sclera (posterior 5/6ths)
ocular conjunctiva
corneal limbus (cornea & sclera join)
canal of Schlemm (poss. not visible)

VASCULAR TUNIC:
ciliary body:
ciliary muscle
ciliary processes
iris
pupil

NERVOUS TUNIC:
retina
lens (It is often fragmented during slide preparation, and only the outline remains.)
suspensory ligaments (not visible?)
anterior cavity
anterior chamber
posterior chamber
aqueous humor
posterior cavity
vitreous humor

eyeball_anterior_half_PC271489

At 40x: Gross anatomy of anterior portion of the eye
Here is a labeled view of the anterior portion of the eye.

vascular_tunic_lens_PC271490

VASCULAR TUNIC, 60x:
ciliary body:
ciliary muscle
ciliary processes
iris
pupil

vascular_tunic_PC271519

VASCULAR TUNIC, 100x: (Here is a labeled version of the anterior vascular tunic and fibrous tunic.)
 ciliary body:
ciliary muscle
ciliary processes
iris
pupil

cornea_200x_PC271515

400x view of cornea, left to right:
posterior epithelium (low cuboidal cells)
Corneal stroma withkeratocytes embedded in collagen fibers
anterior epithelium (stratified squamous epithelium)

optic_nerve_PC271516

At 100x: cross section through rear wall of eye with optic nerve: Here is a labeled view of the rear wall.
 left to right:
optic nerve with parallel axons from ganglion cells
optic disc  (note photoreceptors are absent in retina where the optic nerve is attached)  adventitia (orbital fatty tissue)
sclera
choroid, with melanocytes
retina:
cell bodies of
photoreceptors
bipolar cells
ganglion cells
Here is an extraordinarily good image of the blind spot where the optic nerve exits the rear of the eye.

eye_rear_wallPC271514

300x:  view through the rear wall of the eye showing, top to bottom:
Nervous tunic
ganglion cell bodies
bipolar cell bodies
photoreceptor cell bodies
Vascular tunic:
pigmented cells of choroid
choroid
Fibrous tunic:
sclera

retina_PC271518
Section through the retina 400x

400x view of cross section of retina:     (Here is a labeled version of the cross section of the retina.)
Deep to superficial tissues (left to right):
pigment cells
rods (finer and longer)
cones (thicker and shorter)
outer limiting membrane
nuclei of cones (closer to choroid)
nuclei of rods (further from choroid)
nuclei of:
horizontal cells (closest to receptors)
bipolar cells
amacrine cells (closest to ganglion)
ganglion cell bodiesMullers fibers (vertical fr ganglion cells)

Other images related to the eye: