BMS 302 Exam 2

Glycogen

Made of glucose, animal starch

Hypoglycemia

Low blood glucose levels

Hyperglycemia

High blood glucose levels

Hormone synthesized and secreted by B cells

Insulin

Hormone synthesized and secreted by A cells

Glycogen

Glycogenesis

Glucose synthesized to ATP/glycogen, causes decreased glucose levels

Glycogenolysis

Degradation glycogen to glucose, causes increased glucose levels

Gluconeogenesis

Synthesis of amino acids to glucose, causes increased glucose levels

Lipogenesis

Synthesis of glucose to glycerol, causes decreased glucose levels

Lipolysis

Degradation of triglycerides to free fatty acids and glycerol, causes no change to blood glucose levels

Insulin in facilitated diffusion of glucose

Some organs and cells need the presence of insulin in order to bring glucose across the membrane

Insulin's effect on glucose levels

Decreases blood glucose levels

Stimulus for insulin release

High blood glucose levels

Metabolic processes that are stimulated by/require the presence of insulin

Glycogenesis, glycogenolysis, lipogenesis

Glucagon effect on blood glucose levels

Increases blood glucose levels

Stimulus to release glucagon

Low blood glucose levels

Effect of glucagon in the liver

Glycogenolysis and gluconeogenesis

Insulin:glucaon ratios vary based on

metabolic state (feeding vs. fed)

Epinephrine effect on blood glucose levels

Increase blood glucose levels

Stimulus that causes release of epinephrine

Decreased blood glucose levels

Organ that releases and synthesizes epinephrine

Adrenal medulla

Metabolic process stimulated by epinephrine

Glycogenolysis

Glucosuria

Glucose present in urine

Polyuria

Large quantities of water excreted duw to glucosuria

Polydipsia

Excessive water intake, caused by polyuria

Acidosis

Metabolization of fat because of an inability to metabolize glucose

Type I diabetes cause

Pancreas is not producing sufficient insulin

Type II diabetes cause

Insulin receptors are not functioning

Type I diabetes onset

<20

Type II diabetes onset

>40

Type I diabetes treatment

Insulin injections

Type II diabetes treatment

Dietary control and weight loss

Insulin shock cause

Hypoglycemia

Diabetic coma cause

Hyperglycemia

Recommendation of ADA for diabetes screening

Blood test by 45 years and testing every 3 years after that

Which photoreceptor is responsible for night vision?

Rods

Which photoreceptor is responsible for color vision?

Cones

Fovea

Pit with highest concentration of cones, inner layers of retina brushed aside so its unobstructed

Periphery

Higher concentration of rods than cones

Blind Spot

Where there are no rods or cones because the optic nerve is there

2 factors that determine the power of a lens

1. Curvature of lens
2. Differences in refraction between media

4 Components of the Refractive System of the Eye

1. Cornea
2. Aqueous humor
3. Lens
4. Vitreous humor

Which interface causes the greatest refraction?

Cornea

Focal Point of Lens

The point at which light is focussed

Where must the focal point be for a clear image?

On the retina

Focal Length

Distance between the lens and the focal point

Convex Lens

Converges light, + diopter

Concave Lens

Diverges light, - diopter

Refractive power=

1/Focal length (m)

Emmetropia

Normal vision, .017mm, 59 diopters

3 Reflexes associated with the Near Response

1. Accommodation Reflex
2. Pupillary Reflex
3. Convergence Reflex

What does the accommodation reflex do to the power of the eye lens?

Increases

Why is it necessary to focus the image of a near object on the retina?

So the image is clear

Role of ciliary muscle during accommodation?

Relaxes

Role of sensory ligaments during accommodation?

Tension increases

Which branch of the ANS is responsible for contraction of the ciliary muscle?

Increased PANS

Which branch of the ANS is responsible for relaxation of the ciliary muscle?

Decreased PANS

What type of muscle is ciliary muscle?

Multi-unit smooth muscle

Are light rays parallel or diverging as they enter the eye from a distant source?

Parallel

Are ciliary muscles contracted or relaxed with distant vision?

Relaxed

Are light rays parallel or diverging as they enter the eye from a near source?

Diverging

What must happen to the lens as one moves their gaze from a distant to a near object?

Increase refractive power

What happens to the elasticity of the lens and therefore the ability to increase refractive power as one ages?

Decreases

Presbyopia

Impaired vision as a result of aging

Presbyopia: does the nearpoint of vision increase or decrease?

Decrease

Where is the focal point for presbyopia?

Behind the retina

What type of lens corrects presbyopia?

Convex lens

Pupillary Reflex

Accommodates varying light levels by dilating or constricting, visual acuity

How does the pupillary reflex help focus a near object's image on the retina?

By excluding more divergent rays

Which branch of the ANS is responsible for active pupillary dilation?

Increased SANS

Which branch of the ANS is responsible for active pupillary constriction?

Increased PANS

What type of muscle is the iris?

Multi-unit smooth muscle

How does convergence help with near vision?

Moves both eyes inward to achieve a single image

What branch of the nervous system is responsible for contraction of ocular muscles?

Somatic nervous system

What are 2 potential causes of hyperopia?

1. Flattened lens/cornea
2. Short eyeball

Where is the focal point in uncorrected hyperopia?

Behind the retina

What lens corrects hyperopia?

Convex (+)

What are 2 potential causes of myopia?

1. Increased curve of lens/cornea
2. Long eyeball

Where is the focal point in uncorrected myopia?

In front of the retina

What lens corrects myopia?

Concave lens (-)

How does Snellen's chart help determine the visual acuity of a subject?

By having them read letters that decrease in size that have corresponding values for how well they can see

20/X, top and bottom relation

Top-What subject can see at 20 feet
Bottom-What a "normal person" can see at X feet

Astigmatism

Defective curvature of the cornea or lens of the eye

What are 2 potential causes of astigmatism?

1. Unusual curvature of cornea/lens
2. Abnormal refraction at either axis

How does the astigmatism chart help diagnose the condition?

By having outspreading lines, it'll show if some areas of vision are blurry while others are not by providing various angles and axes

Why can hard lenses be used to treat astigmatism but not soft?

Because the hard lens fills in the abnormal curves of the cornea while a soft lens cannot

Antigen

On cell, determines blood type

Antibody

In plasma, protective response against foreign antigens

Immune Complex

Antigen/antibody combined complex

Blood Group System

Different types of blood

Transfusion

RBC only

Transfusion Reaction

Agglutination of RBC with Rh antibodies

Donor

Person who gives blood

Recipient

Person who receives donated blood

Whole blood

RBC, plasma, antibodies

Packed Cell

RBC without plasma

In vitro

Within the body

In vivo

Within artificial

What antigens are associated with the ABO blood system?

Red cell antigen

Antibodies/Antigens: Type A

Antibody: b
Antigens: A