Human Physiology Flashcards Overview

Hypothermia

When body temperature is below normal.

Hyperthermia

When body temperature is above normal.

Thermoreceptors

Detect changes in body temperature.

Conductive heat gain

Heat transfer from direct contact with an object.

Average body temp

37 degrees Celsius.

Evaporative

This type of heat loss is significantly reduced on a humid day.

Thermogenesis

The generation of heat.

Pyrogens

Cytokines that can increase body temperature and cause a fever.

Heat Stroke

The most dangerous condition related to hyperthermia.

Sweat glands

Effectors for evaporative heat loss.

Skeletal muscle

Effector for generating heat in the body.

Shivering Thermogenesis

Heat production by rapid muscle contraction-relaxation cycles.

Cutaneous Blood vessels

Located below the skin, involved in heat/cold regulation.

Chemoreceptors

Detect changes in O2, pH, CO2, and ions.

Proprioceptors

Detect changes in body movement and position.

Baroreceptors

Detect changes in blood pressure.

Osmoreceptors

Detect changes in the osmolarity of body fluids.

Photoreceptors

Detect light and color.

Nociceptors

Detect pain.

Convex lens

Fixes hyperopia by converging light back to the retina.

Concave lens

Fixes myopia by spreading light to compensate.

Hyperopia

Farsightedness, when the eyeball is too short.

Presbyopia

Age-related farsightedness.

Myopia

Nearsightedness, when the eyeball is too long.

Astigmatism

Blurred vision usually due to an abnormally curved cornea.

Near point vision

Measures how well the eye muscles adjust for focus.

Ishihara test

Test to determine color blindness.

Dichromatic

Ability to see two colors, abnormal response.

Trichromatic

Ability to see three colors, normal response.

Nystagmus

Uncontrollable side-to-side eye movement.

Rinne's Test

Test for conduction deafness.

Weber's Test

Test for sensory deafness.

Vestibulo-Ocular reflex

Coordinates visual and vestibular input during movement.

Bleaching

Temporary altered state of pigment.

Signal Transduction

Process of converting one type of signal to another.

Sound Localization

Ability to locate the source of sound.

5 Sensory cells

Salty (Na+), Sour (H+), Umami (amino acids), Sweet (sugar), Bitter (toxins).

Snellen Eye Chart

Test for visual acuity.

Rhodopsin

A pigment molecule in photoreceptors.

Direct Relationship

Both variables increase together.

Indirect relationship

One variable increases while the other decreases.

Motor unit summation

Increasing number of muscle cells activated.

Length-tension relationship

Optimal muscle length for contraction.

Load-Velocity relationship

Altering shortening speed during contraction.

Concentric

Muscle shortens during contraction.

Isometric

Muscle length doesn't change.

Fatigue

Inability to maintain a given workload.

ATP-CP pathway

Supports very high-intensity muscle activity.

Glycolysis

Supports high-intensity activity.

Citric acid cycle

Supports moderate-intensity activity.

Grip Dynamometer

Instrument that measures grip force.

Clench force test

Tests subject's ability to adjust grip force.

Electromyography

Measures electrical activity in muscles.

Eccentric

Lengthening muscle action.

Hypertrophy

Enlargement of muscle cell.

Atrophy

Loss of muscle cell size.

Cranial Reflex

Reflex integrated in the brain/brainstem.

Spinal reflex

Reflex integrated in spinal cord.

Somatic reflex

Uses somatic motor neurons and skeletal muscle.

Autonomic Reflex

Uses involuntary organs as effectors.

Alpha motor neurons

Innervate extrafusal muscle fibers.

Gamma motor neurons

Innervate intrafusal muscle fibers.

Muscle Spindle

Located in muscle belly; detects stretch.

Golgi Tendon Organ

Located at the junction of muscle and tendon; detects tension.

Reciprocal inhibition

Prevents opposing muscles from working against each other.

Crossed extensor reflex

Stimulus causes withdrawal of one limb and extension of the other.

Patellar reflex

Knee-jerk reflex testing L2-L4.

Biceps Reflex

Tests C5-C6 spinal nerves.

Achilles reflex

Ankle jerk testing S1-S2.

Plantar reflex

Babinski's response; tests cerebral cortex.

Extrafusal fibers

Effectors of the muscle spindle and Golgi tendon organ.

Hyperopia (Farsightedness)

Light focuses behind the retina due to a short eyeball or weak lens. Corrected with a convex lens, which converges light before it enters the eye.

Myopia (Nearsightedness)

Light focuses in front of the retina due to a long eyeball or strong lens. Corrected with a concave lens, which diverges light so it focuses properly on the retina.