Bio 319 Exam 3

All from points on the AI Review.

Calcitonin

inhibits osteoclast activity, stimulates osteoblasts. lowers blood calcium

Calcitriol

Hormonal form of Vit D in kidney, raises blood calcium levels by enhancing calcium absorption

Calmodulin

Does not increase or decrease blood calcium. Binds Ca++ inside cells and activates target proteins.

Estrogen

Induces apoptosis in osteoclasts, prevents apoptosis in young osteoblasts

How does post-menopause affect bone remodeling?

Declines the circulation of estrogen, leading to more osteoclast activity and increasing rates od osteoporosis

Osteoporosis

A condition in which the bones lose mass and become more fragile.

Interferons

Induce antiviral defense. Causes the achy feeling.

p53 5 safeguards

1.DNA Repair
2.Cell Cycle Regulation
3.Triggers apoptosis of cells with damaged genetic material
4.Senescence (forces a damaged cell to stop reproducing)
5.Immune cell activation

p53 percentage of cancers

50% of all human cancers contain a mutated or inactivated p53 gene.

5 layers of epidermis top to bottom and characteristics

1.Stratum Corneum (dead)
2.Stratum Lucidum (dead, keratinized in thick skin)
3.Stratum Granulosum (Moribund)
4.Stratum Spinosum (alive)
5.Stratum Basale (alive)

What’s the difference between moles (nevi), acrochordons (skin tags), and warts.

Moles represent benign melanocytic growths. Acrochordons are benign pedunculated (attached by stalk) skin tags. Warts are epidermal hyperplasias (increase in cell number) caused by HPV.

ABCDEs of Mole Malignancy

Asymmetry, Border irregularity, Color, Diameter (>6mm), Evolving

Subcutaneous bruising

Enzymatic breakdown of hemoglobin into green (biliverdin) and then yellow(bilirubin) pigment in hematomas.

Sudoriferous glands

Sweat (exocrine) glands that secrete water and electrolytes for thermoregulation (and trace nitrogenous wastes).

Prostaglandins (PGs)

Signaling molecules synthesized from arachidonic acid. Increase local inflammatory responses, vasodilation, fever generation, and pain sensitization.

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)

Pharmacological agents (aspirin, ibuprofen, advil, aleve) that inhibit COX enzymes. Blocks PG synthesis to alleviate pain, fever, and inflammation.

Rheumatoid Arthritis

Wrist and hands. Chronic autoimmune disorder (antibody/Ig). Attack synovial membranes. Morning stiffness.

5 types of Ig

M, A, E, D, G

APC

Antigen Presenting Cells (show T cells what to respond to, aka immune system). Found in tumors. 3 types (dendritic cells, macrophages, B cells)

Osteoarthritis

Progressive thinning of hyaline cartilage. Causes osteophytes (bone spurs) to form. Correlated with aging.

Femoral Acetabular Impingement

Genetic (19%): head of femur fits abnormally with hip joint). 3 signs from Dr. Lee for early hip joint destruction (He runs wrong, he’s big, had a rough and tumble life).

Hip issues do what to lower back

Tighten

Diuresis

Urine formation

Portal System (H-H)

Blood encounters two capillary beds connected by portal vessels before returning to the heart.
In hypothalamic-hypopheseal portal system goes from hypothalamic to second capillary bed in anterior pituitary.

Anterior Pituitary

Synthesized by endocrine cells within anterior pituitary. Released into secondary capillary bed. Connected via hypothalamic-hypophyseal portal system. GH, endorphins.

Posterior pituitary

Synthesized in soma within hypothalamus. Shipped in vesicles and stored/released form posterior terminals. Connected via neurosecretory axonal tracts. ADH (hormonal response that helps kidneys conserve water) and Oxytocin.

Where is site of biosynthesis in a nerve?

Soma(body)

How does caffeine cause dehydration?

makes more urine, excretes more sodium and water follows.

Beach volleyball sequence of events (dehydration)

1.Environment: Sun and coastal winds cause rapid evaporative loss of body water
2.Caffeine + Alc: Caffeine causes excretion of sodium in urine taking water with it, antagonist to ADH. Ethanol in alc directly inhibits ADH. Leads to intense diuresis.
3.Osmolar Elevation: Blood osmolarity increases; Normal around 300, once it gets to 305/306 mOsm/L causes passing out. Alc also depresses urge to drink water.
4.If an unconscious person vomits it can get into lungs causing life-threatening pulmonary aspiration.

Gout

Inability of kidneys to clear uric acid. Needle-like uric acid crystals in joint cavities. Lower extremities and big toe (gravity). Dietary intake.

Metabolic parallel (GLP-1 Agonists and Diabetes)

Unregulated blood sugar can cause glucose crystallization, leading to ischemia and tissue necrosis with similar consequences of gout. GLP-1 can help mitigate risk and effects.

What is the most prevalent/ amino acid in higher vertebrates?

Glutamate. Paradigm shift, savory was not an official taste until discovery of glutamate. Now 5 fundamental taste modalities are sweet, sour, bitter, salty, and Unami (savory)

Movement

Produce tension to move things

Posture

Baseline tension at all times

Joint stability

Constant tension holds joints together.

Thermogenesis

Shivering, non-voluntary skeletal muscle movement.

Which tissues have RMP

All

Which tissues have AP

Excitable tissues: nervous, muscle

Sliding Filament Theory

Actin slides over myosin to create muscle contraction (shortening). Actin and myosin ‘ATPase’ don’t actually shorten.

Extensible

Tolerate stretching

Elastic

Snap back into position after stretch.

How are skeletal muscle fibers classified?

How quick do they contract relatively? How do they generate ATP?

Skeletal muscle fiber types

Type 1: Contract slowly, aerobic respiration, fatigue resistant, marathon runners
Type 2a: Fast twitch, aerobic and anaerobic respiration, intermediate fatigue resistant, general performance
Type 2b: Fast twitch (Max force), anaerobic respiration, fatigue rapidly, sprinters

How does founder effect relate to skeletal muscle fiber types and islands.

The founders of Kenya and Jamaica had high type 1 and type 2b muscle fiber ratios respectively making their populations more inclined to a certain athletic performance. Islands specifically are good bio labs because they are isolated and scientists can travel island to island (Florida keys feline polydactyl (6 toed cats)).

What are myoblasts in embryos

Immature cells that develop into muscle cells. During skeletal muscle development myoblasts fuse to form long myotube, each myoblasts contributes a nucleus, which is why muscles are multi-nucleate.

3 names for muscle cells

myofiber=myocyte=muscle cell

Benefits of creatine

Brings water to muscle
Helps neurocognitive function, prefrontal cortex’s
Helps recovery times (muscle soreness type 2)

Fascia

Band or sheet of connective tissue (collagen) that attaches to, stabilizes, encloses, and separates muscles and other internal organs.

What are the fascia types?

Superficial, deep, visceral (organ), parietal (walls of cavity).

What is the largest lymphatic vessel?

Thoracic duct

PCS

Pre-capillary Sphincters. Rings of smooth muscle surrounding arterial capillaries that contract or relax under local metabolic control to regulate tissue.

Skeletal muscle cylindrical hierarchy

Whole muscle: surrounded by epimysium
Muscle fascicle: individual muscle fibers surrounded by perimysium
Muscle cell: wrapped by endomysium
Myofibril: Units of cylindrical organelle
Myofilaments: Protein chains compromising actin and myosin

Muscle contractile cycle (Tug-o-war)

1.Cross Bridge (Grab rope): Ca++ released, troponin binds, myosin bind actin
2.Power Stroke (tug): Myosin head pull actin over top (don’t shorten)
3. New ATP → Myosin head detach (set down): Cramp if no ATP
4.ATP hydrolysis → recock myosin (grab more): ATP to ADP + PO4

What shortens during muscle contraction?

H-band, I-band, sarcomere

What doesn’t shorten?

A-band, actin, myosin

Types of muscle soreness

1.Immediate: during exertion, lactate to liver
2.Delayed onset: 24-48 hours post, hypertrophy, micro tears in actin/myosin
3.Severe: weeks, tendon and ligaments have poor blood supply

Which of actin and myosin is thick and thin?

Actin is thin, myosin is thick

Troponin and Tropomyosin

Calcium binds to troponin which then binds to tropomyosin which reveals myosin-binding active sites, blocking them while at rest.

Satellite stem cell recruitment

Microtears, testosterone recruits satellite cells which donate nuclei to damaged muscle, extra nuclei increase myofibril density and muscle cross-sectional area.

Twitch vs. Tetany

A single action potential produced brief contraction-relaxation cycle known as a twitch. Repetitive APs eventually sustain max contraction known as tetany.

Why do you cramp

During step 3 (New ATP) of muscle contraction, if no available ATP then myosin does not detach actin, creating a constant contraction.

Rigor Mortis

Upon death, ATP synthesis stops while calcium leaks opening active sites. Without new ATP, it’s like a constant cramp causing total body rigidity.

What does Botox help with

Migraines

What are the action potential voltage differences for muscle and neurons.

Muscle (-85 → 20), Neuron (-70 → 30).

What are the numbers of sodium and potassium that goes in and out of the Na+/K+ ATPase pump

3 Na + out / 2 K+ in

Threshold voltage

-55 mV. An action potential is triggered and it cannot be stopped (all or nothing)

Describe what is happening in each stage on an action potential

RMP: Maintained at -85 or -70 by Na/K ATPase pump (3Na out 2K in) and slow leak K channels.
Threshold: reach -55, triggered AP and cannot be stopped
Depol: VG Na+ channels open, sodium rushes INTO cell down gradient, makes membrane potential positive.
Peak Transition: At peak depol VG Na channels slam shut
Repol: K rushes OUT through open VG K channels, restoring internal negativity
Hyperpol: VG K channels slow to close, excess K diffuses making more neg than resting (-90)
Return: ATPase pump and leak channels re-establish baseline RMP

More vs Bigger APs

There is no such thing as a bigger AP, they are all the same. However, there can be more of them to create a stronger contraction.

EPSP vs IPSP

EPSP gets closer to threshold, IPSP gets farther away from threshold

Medulla Oblongata

Controls HR, BP, RR

Mechanisms of Narcotics / Opiates

Opiod agonist binds opioid receptors on medullary neurons causing extreme hyperpolarization. Makes neurons unresponsive and depresses respiratory drive.

Describe the growth plate.

The growth plate, or the epiphyseal plate, is hyaline cartilage involved in longitudinal growth. On the epiphyseal side, new cartilage is produced. Toward the diaphyseal side, cartilage is replaced by bone. This ongoing addition and replacement allow the bone to grow longer.

Describe the 5 growth plate regions.

In order from epiphyseal side to diaphyseal side.

1. Resting or reserve cartilage; anchors and maintains the plate.

2. Proliferation; Chondrocytes undergo mitosis and form stacks, new cartilage is produced which contributes to lengthening.

3. Hypertrophy/maturation; Chondrocytes mature and enlarge, cartilage partitions become thinner.

4. Calcification; Cartilage matrix calcifies, cells die, temporary framework.

5. Ossification; Vessels and bone cells enter from diaphyseal side. Osteoblasts deposit bone on framework.

What is the epiphyseal line?

When skeletal maturity is reached, bone replaced the remaining growth plate cartilage, leaving an epiphyseal line.

Histamine vs Epinephrine

Histamine is vasodilator, bronchoconstrictor. Epinephrine is vasoconstrictor, bronchodilator.

What is the periosteum?

It covers the outer surface of bone except where articular cartilage covers joint surfaces. It includes an outer fibrous region and an inner cellular region for growth and repair. It also has nerves which is what makes fractures painful.

List common broken bone (fracture) verbage and what it means.

Transverse: the break is across the bone roughly perpendicular

Longitudinal: fracture line follows long axis

Oblique: Fracture line at an angle to the long axis

Spiral: Fracture line winds around the bone (commonly a twisting force)

Displaced: Fragments lose their normal alignment

Comminuted: Bone breaks into multiple fragments

Greenstick: incomplete fracture, one side breaks the other bends

Closed/simple: fracture does not communicate with outside

Open/compound: Wound communicates with fracture, bone doesn’t need be visible

Complete: break extends across full thickness

Depressed: fragment is pushed inwards, classically in the skull

Viral illness

Virus infects cell → interferons produced → p53 goes up → makes us achy → get medicine → sleep

Sarcolemma

Cell membrane

Cytoplasm

Sarcoplasm

Endoplasmic Reticulum

Sarcoplasmic Reticulum

Creatine Kinase job

Use phosphocreatine to rapidly regen ATP from ADP.

What are two types of acetylcholine (ACh) receptors

Nicotinic, ion channel that opens when ACh binds. Muscarinic, uses G protein to change what nearby channels do.

Why does ACh slow the heart

ACh binds vagus nerve, inward pacemaker current decreases, cell takes longer to reach threshold

MIFCC

Binding changes proteins shape. Receptor changed to channel after ACh binds.

Difference between peptide and steroid hormones

peptides: bind on cell surface
steroid: bind within cell

NMJ

Neuromuscular junction, site where motor neuron releases ACh to signal skeletal muscle fiber.

How to recognize motor end plate?

Opposite nerve terminal, has nicotinic ACh receptors

How can skeletal muscle serve as source of nutrition

Muscle stores protein, during fasting, muscle broken down into AA for fuel.

What does cyanide do to ETC

Inhibits last complex, electrons can no longer reach oxygen.

What does sarin nerve gas do

Inihibits breakdown of ACh, prolonged activation of ACh receptors, skeletal muscles become paralyzed.