Anatomy 2 Lecture 1-6

What is the human body made out of?

Human cells, microorganisms

What is a virome?

Total collection of viruses

How many interacting cells in the body?

30-40 trillion cells

What is a microbiome?

Outnumber human cells in a body by a factor of 10 to 1

What is the body?

Flowing changing process; colony of a plethora of things

What makes up are body?

Microbes, bacteria, new bacteria, inorganic substances even though we call everything in our body “I”

How are genetics shown throughout our body?

Genetics can be turned on and off when needed even if genetics arent’s shown

What is the differential gene expression?

Genes that can be expressed in different ways whether healthy or unhealthy

What is planned epigenesis?

An organism develops according to a genetically guided sequence in which different genes are turned on and off at different times and in different cells

What was created through the big bang?

The beginning of time which is also beginningless, elements of the period table mainly hydrogen, helium, created from atomic explosions

How did the big bang create us?

Energy and matter are both created from within each other and because matter cannot be created or destroyed we are made up of dead star dust

How have we evolved as a society?

Through cultural technology and human evolution

How must we use food?

Through the storage of food for energy for times that will have scarcity of food

What is bad through overconsumption?

With the added storage we grow to add more adipose and more blood supply causing more resistance and the heart muscle to grow to not be enough to filtrate the entire body leading to blood vessels bursting - aneurysms and strokes

What is autopoiesis?

The idea that living organisms are self-organizing and maintaining while nonliving structures are not

What is the cell theory?

Life is any independent structure made up of one or more microscopic units called cells

Gross anatomy

Study of parts visible to the naked eye such as cytology and histology (microscopic)

Physiology

Study of how the parts of the body function in the relationship to one another

What occurs in a sensory system?

A stimulus activates a receptor, which transduces it into an action potential that travels to the brain where it triggers sensation/perception

What is transduction?

The receptor converts the stimulus into an electrical signal to produce a receptor potential to lead to action potentials

What is transmission?

Action potentials travel along sensory neurons toward the CNS

What is a stimulus?

Form of energy that activates receptor endings of a sensory neuron

What are sensations?

Conscious responses to the stimuli

What is perception?

The brain’s understanding of what to feel - negative or positive based on the sensation

How do we process perceptions?

Subjectively because our brain interprets sensory information rather than simply recording the world exactly as it is

What types of receptors do animals have that humans don’t?

Certain frequencies of light

What are cutaneous receptors?

(Skin Receptors) - that are near the body surface sensing touch, pressure, cold, warmth, and pain

What are the simplest receptors?

Free nerve endings

What are free nerve endings?

Receptors that have thin or no myelinate dendrites that can be found in hair to detect movement (itch) or chemicals

What are mechanoreceptors?

Receptors that detect changes in pressure, position, or acceleration (vibration)

What are thermoreceptors?

Receptors that detect heat or cold

What are nociceptors?

(Pain receptors) that detect tissue damage

Why is pain a manafactured experience?

Nociceptors do not create pain - instead they send signals to the brain indicating tissue damage but allow us to interpret the sensation of pain

What are chemoreceptors?

Receptors that detect ions or molecules - oxygen, ph, carbon dioxide, taste and smell

What are osmoreceptors?

Receptors that detect changes in solute concentration in surrounding fluid - water homeostasis

What are photoreceptors?

Receptors that detect the energy of visible light - rods and cones

What are encapsulated receptors?

Receptors whose nerve endings are surrounded by a capsule of epithelial or connective tissue - Merkel’s discs, Meissner’s corpuscles, Ruffini endings, Pacinian corpsucles

What are Merkel’s discs?

Adapt slowly and are important to steady touch

What are Meissner’s corpsules?

Respond to light touching

What are Ruffini endings?

Sensitive to steady touch and pressure?

What are Pacinian corpuscles?

Are sensitive to deep pressure and vibrations

Why are action potentials the same?

Brain identifies all action potentials the same but they are interpreted differently by the amount of times the signal fires and the receptors that are activated and more neurons

What is sensory adaptation?

The diminishing response to an ongoing stimulus - falls into the background such as getting used to your own perfume

What are somatic sensations?

Sensations that allow the somatosensory cortex in the brain to recognize what is happening to your body, where your body is positioned, and how it is interacting with its surroundings

What are mechanoreceptors?

Sensory receptors that detect physical changes like stretching, pressure, and movement in skeletal muscle, joints, tendons, ligaments and skin

What is referred pain?

A matter of perception - experiencing pain but the real source of the pain is in another place in your body

What is phantom pain?

The sensation that amputees feel when they sense the missing part as if it were still there

What do opiates/endorphins do?

Opiates allow us to reduce the experience of pain but natural chemicals such as endorphins allow us to reduce pain too

What are taste and smell?

Chemoreceptors that travel to the brain where they go to the limbic system and can be connected to emotions and memories

What is gustation?

The sense of taste - sensory organs called taste buds hold the taste receptors in the tongue, roof of the mought, and throat, they detect chemicals dissolved in saliva

What are the five general taste categories?

Sweet, sour, salty, bitter, and umami

What is umami?

Savory taste, usually found as preservatives in food to make you want more food

What is olfaction?

Sense of smell with olfactory receptors that detect odor molecules

What is olfactory epithelium?

Specialized tissue located in the upper part of the nasal cavity containing olfactory receptors

What are olfactory bulbs?

Brain structures that receive and begin processing smell information

What is a vomernasal organ?

Has receptors that can detect pheromones. which are signaling molecules with roles in sexua1 attraction

What is vision?

An awareness of the position, shape, brightness, distance, and movement of visual stimuli as detected by the sensory organs, the eyes

What is the eye built for?

Photoreception

How many layers does the eye have?

3 layers called tunics - sclera, cornea; choroid, ciliary body, iris; and retina

What is the outer layer of the tunic?

The sclera and transparent cornea

What is the middle layer of the tunics?

Choroid, ciliary body, and iris

What is the inner layer of the tunics?

The retina

What does the sclera do?

Protects the eye

What does the dark-pigmented choroid do?

Underlies the sclera and prevents light from scattering - has most blood vessels

What is behind the cornea?

Pigmented iris

What is the pupil?

The hole at the center of the iris - entrance for light which can be adjusted depending on the level of light present

What is the lens?

Behind the iris - attached to the ciliary body, a muscle functioning in the focusing of light

What is the retina?

A thin layer of neural tissue at the back of the eyeball that contains photoreceptors (rods and cones) - retina→optic nerve→ thalamus→ visual cortex

What is aqueous humor?

A clear fluid bathes both sides of the lens

What is vitreous humor?

Fills the chamber behind the lens

What are rod cells?

Sensitive to dim light and detect changes in light intensity ( night vision)

What are cone cells?

Respond to high-intensity light and contribute to sharp daytime vision (color)

What disrupts the normal eye function?

Disease, injury, inherited abnormalities, and aging

What causes color blindness?

Missing cone cells - visual spectrum

What is red-green color blindness?

The inability to distinguish red and green colors in dim light (and sometimes bright light) due to a lack of red and green cone cells

What is astigmatism?

One or both corneas have uneven curvature and cannot bend to the same focal point - causes the vision to be blurry in bright lights

What is nearsightedness (myopia)?

Results when the image is focused in front of the retina - but blurry background and wide eye

What is farsightedness (hyperopia)?

Results in an image focused behind the retina but the main focus is blurry - condensed of shortened eye

What are cataracts?

The gradual clouding of the lens associated with aging and diabetes, can completely block light from entering the eye - Random blackness

What is macular degeneration?

An age-related degeneration of the retina - random brightness

What is glaucoma?

Results from excess of fluid in the eyeball, causing pressure on the retina - blurriness