S&F Exam 1

How many different cell types are there?

250

What reflects the role that the cell plays in the body?

Structure of cells.

What are the 3 main components of the cell membrane?

Phospholipids, carbohydrates, proteins.

What is the primary component of every cell membrane?

Phospholipids.

What is the term for fluid within the cell?

Intracellular fluid (ICF).

What is the term for fluid outside the cell?

Extracellular fluid (ECF).

What does hydrophilic mean?

Likes water, dissolves in water, cannot pass through the membrane.

What does hydrophobic mean?

Does not like water, loves lipids, can pass through the membrane.

What is glycocalyx?

Sugar coating on cells.

What role do proteins play in the body?

They exist in every part of the body, including cell membranes.

What types of proteins are found in the cell membrane?

Receptors, enzymes, ion channels, transport proteins.

What is the function of receptors?

Receives signals from other cells.

What is the role of enzymes in the body?

Breaks down chemical messengers and terminates their effects.

What are ion channels?

Tunnels that go through the membrane allowing certain ions to pass.

What is the function of transport proteins?

Takes ions that cannot pass through the membrane on their own safely to the other side.

What are membrane functions?

1. Physical boundary 2. Communicator 3. Control passage in/out of cell 4. Maintain gradient.

What is endocrine signaling?

Hormones that signal between cells far apart.

What is paracrine signaling?

Signals between cells that are close together.

What is a gradient?

The difference between side A and side B of a membrane.

What does going with the gradient mean?

Moving from high to low concentration.

What does going against the gradient mean?

Moving from low to high concentration.

What is passive transport?

Movement with the gradient; no ATP required.

What are types of passive transport?

1. Simple diffusion 2. Facilitated diffusion.

What is simple diffusion?

Hydrophobic substances pass through the membrane without help.

What is facilitated diffusion?

Hydrophilic substances that use ion channels and transport proteins to pass through the membrane.

What is active transport?

Movement against the gradient requiring ATP.

What is osmosis?

Diffusion based on a solute gradient.

What is an organ?

A collection of 2 or more tissues.

What is a tissue?

A group of similar cells working together for a specific function.

What are the levels of organization in the body?

1. Chemical level 2. Cellular level 3. Tissue level 4. Organ level 5. Organ system level 6. Organism level.

How many organ systems are there in the body?

11.

List the organ systems.

END SMURF MILC

1. Integumentary 2. Skeletal 3. Muscular 4. Nervous 5. Endocrine 6. Cardiovascular 7. Lymphatic 8. Respiratory 9. Digestive 10. Urinary 11. Reproductive.

What is homeostasis?

Maintenance of a relatively stable internal environment.

What are variables?

Things that can change.

What is a set point?

Normal/optimal value for a variable.

Who explained homeostasis?

Walter Cannon.

What is the order of the feedback loop?

1. Stimulus 2. Receptor 3. Control Center 4. Effectors 5. Physiological Response.

What is a stimulus?

A change that causes a variation in a variable.

What is a receptor?

Sensors in the body that detect changes.

What is a control center?

Processes the signal and determines a response.

What are effectors?

Tissues/organs that carry out the plan to produce a physiological response.

What are types of physiological responses?

Negative feedback loop and positive feedback loop.

What is negative feedback?

Response to reverse the change in the variable and reach homeostasis.

What is positive feedback?

Makes change in variable bigger.

Give an example of negative feedback.

Movement of skeletal muscles and joints.

Give an example of positive feedback.

Childbirth.

What is a solute?

Particles that get dissolved in water.

What are compartments?

Locations of water in the body.

What is the normal osmolarity level?

285-295.

What is plasma?

Liquid part of blood making up 20% of blood.

Where does water come from?

The bloodstream.

Where does urine come from?

Filtering of blood.

What is hypertonic?

More solute, more concentrated, higher osmolarity.

What is hypotonic?

More H2O, less concentrated, lower osmolarity.

What happens in ICF hypotonic conditions?

Water moves out of the cell, causing it to shrink.

What happens in ICF isotonic conditions?

Equal concentrations, no net water movement.

What happens in ICF hypertonic conditions?

Water moves into the cell, causing it to swell.

What is the most abundant ion?

Sodium (Na+).

What happens when the gradient goes away?

Nerves and muscles shut down.

What percentage of body weight is skin?

16%.

How much area does skin cover?

21 square feet.

How many miles of blood vessels are in the body?

11 miles.

How many sweat glands are there per square inch of skin?

300 sweat glands.

What is the thickest skin?

Feet.

What is the thinnest skin?

Eyelids.

What are the four functions of skin?

1. Thermoregulation 2. Melanin production 3. Barrier to water 4. Barrier to infection.

What is keratin?

A protein in outer skin cells that prevents bacteria from entering.

What is acid mantle?

Slightly acidic skin that keeps bacteria out.

What are dendritic cells?

Cells that take bacteria to lymph nodes to be destroyed.

Is vitamin D absorbed through the air/sun?

No.

What are general senses?

Touch, pressure, pain, temperature.

What are the layers of skin?

Epidermis and dermis.

What is the hypodermis?

Subcutaneous tissue below the skin that contains fat, blood vessels, and nerves.

What tissues make up the epidermis?

Epithelial tissue.

What is the stratum corneum?

The most superficial layer of the epidermis containing dead skin filled with keratin.

What are keratinocytes?

Special epithelial cells that produce keratin.

What is stratum basale?

The deepest layer of the epidermis, containing stem cells.

What are stem cells?

Cells capable of differentiating into other cell types and producing keratinocytes.

What does mitotic mean?

Capable of dividing and producing other cells.

What does a melanocyte do?

Produces melanin in the epidermis.

What is a Merkel cell?

Touch receptor connected to nerves from the dermis.

Osmolarity of water

0

ICF of Na+

12

ECF of Na+

145

ICF of K+

150

ECF of K+

4

Na+K+ pump

Uses ATP to push against their gradients

Why is the Na+K+ pump needed

Because equilibrium would be reached, so there would be no gradient

Where does Na+ go in the Na+K+ pump

Gets pumped back out of the cell

Where does K+ go in the Na+K+ pump

Gets pumped back into the cell

Explain why some people have darker skin than others

Everyone has the same number of melanocytes

• different amounts of melanin in melanocyte

• different metabolism speeds when working up to Stratum Corneum

• different kinds of melanin

Types of melanin

• Eumelanin

• Pheomelanin

Eumelanin

Black/ brown pigment

Pheomelanin

Yellow/ red pigment

Melanin’s role with sun exposure

Protects DNA in the nucleus from sun damage

• Darker pigment = more protected

Dematophagoide

Dust mite

• East stratum corneun that falls off

Where to find dematophagoides

• Pillows

• Sheets

• Non-leather sofas

• Carpet

What type of tissue is the dermis made of

Areolar connective tissue

Things found in the dermis

• Hair follicles

• Nail roots

• Blisters

• Sweat glands

• Mammary glands

• Piloerector muscles

• Oil glands

Blisters

Fluid formed from friction that separates the epidermis from the dermis