Lab 11 Flashcards
Scattered throughout the body that include the somatic senses - touch, pressure, pain, temperature and proprioception and the visceral senses, which provide information about internal organs
General sesnses
Vision, hearing, equilibrium, taste and smell have distinct receptor cells that are restricted to the head and are localized in complex sensory structures (eye and ear) or in distinct epithelial structures (taste buds and olfactory epithelium)
Special senses
Functions as padding and insulation within the orbit to protect the eye
Adipose tissue
“White of the eye”
Protects and shapes the eyeball and provides a sturdy anchoring site
Sclera
Transparent, anterior portion of the sclera
Allows light to enter the eye and it helps bend (refract) light rays so they are focused on the photoreceptors in the retina
Cornea
Solid white cord of sensory nerve fibers
Optic Nerve III
Skeletal muscles provide rotary movements of the eye, focus the eye for optimum vision and anchor the eye in the bony orbit
Appear as flat bands on the surface of the eye
Extrinsic eye muscles
Found in front of lens between lens and cornea (anterior cavity)
Aqueous humor
Forms a fluid cushion, retain eye shape, provides a root for nutrient an waste transport
Aqueous humor
Outermost layer of the eye
Sclera and Cornea
Middle layer of the eye includes:
Iris, ciliary body, choroid
The coloured, circular portion of the eye that lies anterior to the lens
Consists of two layers of muscles - inner circular and outer radial smooth muscles
Iris
Inner circular and outer radial smooth muscles arranged around a central opening called the:
Pupil
In close vision and bright light, the circular smooth muscles of the iris _______ and the pupil becomes _______, as a result, less light enters the eye
Contract: constricted
In distant vision and dim light, the radial smooth muscles _______ and the pupil _______, allowing more light to enter the eye
Contract; dilates
Is normally flexible and changes shape to focus light rays for close and far vision
Crystalline lens
The lens is held in place by _______ _______ which are attached to the ciliary body
Suspensory ligaments
Is attached to the iris posteriorly and is made up of ciliary processes and ciliary muscles
Ciliary body
Control the shape of the lens
Ciliary muscles
Contain capillaries that produce the aqueous humor
Ciliary processes
Continuous with the ciliary body and extends around the posterior of the eye
Highly vascular and darkly pigmented tissue
Functions to absorb excess light rays to prevent reflection and scattering of light within the eyeball
Choroid
Choroid has an iridescent portion (“rainbow”, in sheep) that enhances night vision by reflecting light back onto the:
Retina
Forms the innermost layer of the eye, is very thin and easily separated from the choroid
Very thin yellow layer which most likely has fallen inwards onto the vitreous body/humor
Held in position up against the choroid by the vitreous body in the intact eye
Retina
The retina consists of two layers:
Outer pigmented layer (next to the choroid)
Inner neural layer
The neural layer is composed of three main types of neurons:
Photoreceptors
Bipolar cells
Ganglion cells
Photoreceptor cells, the rods and cones convert light energy into signals that are sent to the bipolar cells and then back to the ganglion cells where the ______ _____ are generated
Action Potentials
The ganglion cell axons leave the back of the eye as the
Optic nerve
The percentage of total blood volume occupied by RBCs is called the _______ and this value is about 45%.
Hematocrit
The hematocrit is determined by centrifuging a sample of _______ blood.
Heparinized
Heparin prevents:
Clotting of blood
The heavier formed elements are packed down by centrifugal force and the less dense plasma remains at the:
top
The hematocrit can vary in healthy individuals. For males, the value is _______ while in females it is ______.
40-54%; 38-46%
Leukocytes and platelets contribute less than ____ of blood volume.
1%
Plasma makes up most of the remaining ____ of whole blood.
55%
Uses a series of lithographed colors that lustrate the tints of blood ranging from 10% to 100% hemoglobin concentration The scale us accompanied by a booklet containing tear-away sheets of prepared paper. A sample of blood is placed of the paper and the color of the blood is matched with the appropriate standard color of the scale.
Tallquist Scale
An instrument which compares hemoyzed sample of blood wth a color standard by moving a slide on the __________ back and forth until the”two halves of the green field match, A numerical value in grams Hb/100 mi of blood is attained on the upbe host scale by the index mark on the slide.
Hemoglobinometer
Are located on the RBC surface
Antigens
Are located in the blood plasma
Antibodies
The term Rh positive (Rh*) signifies the presence of ________ in the blood. Rh positive individuals carry ________ in their blood and do not form antibodies against the antigen.
antigen D
The individuals in the population that do not have antigen D present in their blood are termed _________. These individuals will form antibodies against antigen D if it is introduced into their blood and agglutination of the red blood cells can occur.
Rh negative
The Rh system differs from the ABO blood group system in that there are no ______ occurring antibodies are present in the plasma.
Natrually
An abnormally low red blood cell count, for example, could furnish evidence that indicates _______. Signifies a decreased amount of hemoglobin in the blood and consequently a decreased amount of oxygen will reach the tissues. Could result from a decreased production of erythrocytes if deficiencies in iron or Vitamin B12 occurred or if certain types of malignancies were present. May also be caused by increased destruction or malformation of red blood cells as might occur in cases of severe infections, sickle cell anemia or incorrect transfusions.
Anemia
The hematocrit and hemoglobin evaluations are the most important tests in the diagnosis of _______
Anemia
A condition characterized by above normal red blood cell counts, may be due to living at high altitudes or red marrow malignancy.
Polycythemia
A tool used for manual cell counting. As the name implies it was originally invented for quantifying blood cells.
A hemocytometer (also known as a haemocytometer or a cell counting chamber)
In healthy individuals, the white blood cell count ranges between ______ and _______ white blood cells per cubic millimeter of blood.
5,000 and 10,000
A white cell count of more than 10,000 is called ________.
Leukocytosis
A white blood cell count significantly less than 5,000 is termed _________.
Leukopenia
______ conduct blood away from the heart and ______ conduct blood towards the heart
Arteries; veins
Interconnecting the two major blood vessel types are microscopic _______. Consist of only a single layer of endothelial cells (simple squamous cells) and a basement membrane. The exchange of materials between the circulatory system and the tissues only occurs through these thin walled _______.
Capillaries
Three structural layers (tunics) make up the wall of an artery and vein:
Tunica Interna
Tunica Media
Tunica Externa
The innermost layer, composed of a single layer of endothelial cells. In some of the large arteries this layer also includes an internal elastic membrane (known as the
elastica interna) which appears as a thin, bright, scalloped line.
Tunica interna (intima)
The middle layer, consisting mainly of smooth muscle and elastic fibers running in a circular direction around the lumen.
Tunica media
The outer layer, composed of fibrous connective tissue and fat cells. In some of the larger arteries the tunica media and tunica externa are separated by an external elastic membrane, the elastica externa.
Tunica externa (adventitia)
Consists of a layer of endothelial cells. There is no elastica interna.
Veins - Tunica Interna
Composed mainly of circular smooth muscle cells.
Veins - Tunica Media
Composed of loose fibrous connective tissue with fat cells.
Veins - Tunica Externa
The upper two chambers are the ______. The lower two chambers are the ______.
atria; ventricles
The ______ are the thin-walled receiving chambers for blood returning to the heart from veins
Atria
Are the pumping chambers and have a very thick muscular wall.
Ventricles