anatomy and physiology Flashcards
What is hair composed of?
Keratinized cells
What are the types of hair?
- Lanugo hair
- Vellus hair
- Terminal hair
What is the role of carotene?
A pigment contributing to the yellowish hue in lighter skin
What is the effect of UV radiation on skin color?
Stimulates melanocytes to produce more melanin
What are the histological characteristics of nails?
- Nail plate made of keratinized epithelial cells
- Nail bed consists of an epidermis with keratinocytes
What are freckles?
Small flat spots caused by increased melanin
What is a blister?
Raised fluid-filled sacs that form on the skin surface
What are stretch marks?
Linear streaky scars that appear on areas that have stretched rapidly
What are keloids?
Raised thick scars formed from excessive collagen production
What is the primary cause of leprosy?
Mycobacterium leprae
What is the significance of the lunula?
The area where new nail cells are formed
What are calluses?
Thick hard areas of skin caused by prolonged pressure or rubbing
What is a ball-and-socket joint?
A joint where the spherical head of one bone fits into a cup-like depression of another bone, allowing for a wide range of motion.
Give an example of a ball-and-socket joint.
Shoulder and hip.
What is a hinge joint?
A joint where a convex bone surface fits into a concave bone surface, allowing movement in one direction.
Give an example of a hinge joint.
Elbow, knee, fingers, toes.
What is a pivot joint?
A joint where a rounded or cylindrical bone fits into a ring-shaped bone and ligament structure, allowing rotation around a single axis.
Give an example of a pivot joint.
Neck.
What is a condyloid/ellipsoidal joint?
A joint where an oval-shaped condyle fits into an elliptical cavity, allowing movement in two planes.
Give an example of a condyloid joint.
Wrist and knuckles.
What is a saddle joint?
A joint where a concave surface fits into a convex surface like a saddle, allowing movement in two planes but is more flexible.
Give an example of a saddle joint.
Thumb.
What is a gliding/plane joint?
A joint with flat or slightly curved surfaces allowing bones to slide over each other.
Give an example of a gliding joint.
Wrist and ankle.
What is a cartilaginous joint?
A joint where bones are connected by cartilage, allowing slight movement or flexibility.
Give an example of a cartilaginous joint.
Pubic symphysis and costal cartilage.
What are tendons?
Tough, flexible bands of connective tissue connecting muscles to bones.
What is the origin of a muscle?
Stationary attachment point of a muscle.
What is the insertion of a muscle?
Point that moves during muscle contraction.
What is spongy (cancellous) bone?
Lighter and less dense bone found in the ends of long bones.
What is the function of bone marrow?
Produces blood cells and stores fat.
What are lacunae?
Spaces within lamellae where osteocytes reside.
What are canaliculi?
Small channels connecting lacunae, allowing osteocytes to communicate.
What are perforating canals?
Canals connecting Haversian canals to supply nutrients.
What are trabeculae?
Thin branching plates of bone in spongy bone meant to resist stress.
What are the functions of bone?
- Support body structure
- Store minerals
- Osteogenesis
- Bone remodeling
- Protection of organs
- Movement
What is red bone marrow?
Involved in production of blood cells (hematopoiesis).
What is yellow bone marrow?
Composed of fat cells and converts to red bone marrow in times of need.
What is the function of cartilage?
- Shock absorption
- Allows bones to glide over one another
- Maintains shape and structure
- Facilitates growth of long bones
What hormone regulates calcium and phosphate levels in the blood?
Parathyroid hormone (PTH).
What is bone remodeling?
Process of bone breakdown and formation to maintain calcium and phosphate balance.
What does RANKL stand for?
Receptor activator of nuclear factor-kB ligand.
What are erythrocytes?
Red blood cells that carry oxygen throughout the body.
What are leukocytes?
White blood cells that defend the body against infections.
What are thrombocytes?
Platelets involved in blood clotting.
What is intramembranous ossification?
Process where mesenchymal stem cells differentiate into osteoblasts in flat bones.
What is endochondral ossification?
Replaces hyaline cartilage with bone, mostly for long and short bones.
What are cervical vertebrae?
Vertebrae found in the neck region, small and lightweight.
What are thoracic vertebrae?
Vertebrae found in the upper and mid back attached to ribs.
What are lumbar vertebrae?
Largest and strongest vertebrae found in the lower back.
What are cruciate ligament tears of the knee?
Rupture or tear of ACL or PCL leading to knee joint instability.
What are meniscus tears of the knee?
Damage to meniscus cartilage caused by twisting or compression forces.
What is a fracture?
Breaks or cracks in bones caused by trauma, stress, or diseases.
What is the treatment for fractures?
Rest, immobilization, physical therapy, and possibly surgery.
What is tension production in skeletal muscle?
Produced by sliding filament theory controlled by motor neuron release of acetylcholine.
How is tension produced in cardiac muscle?
Through sliding filament mechanism regulated by pacemaker cells.
How is tension produced in smooth muscle?
Generated by interaction between actin and myosin, regulated by calcium ions.
What is the physiology of skeletal muscle contraction?
ACh release causes action potential in muscle fiber, triggering calcium release.
What initiates spontaneous action potentials and calcium influx in the heart?
Atrial node
What regulates tension production in smooth muscle?
Interaction between actin and myosin, regulated by calcium ions
What is the first step in the physiology of skeletal muscle contraction?
A motor neuron releases acetylcholine (ACh) at the neuromuscular junction
What triggers the release of calcium ions from the sarcoplasmic reticulum in muscle contraction?
Action potential traveling along the sarcolemma and into the T-tubules
What binds to troponin on actin filaments during muscle contraction?
Calcium ions
What is formed when myosin heads bind to actin?
Cross-bridges
What theory explains muscle contraction involving actin and myosin?
Sliding filament theory
What is the role of ATP in muscle contraction?
Causes myosin to detach from actin and re-cock for another cycle
What happens during skeletal muscle relaxation?
Calcium ions are actively transported back into the sarcoplasmic reticulum
What returns to its resting state when calcium levels decrease?
Troponin and tropomyosin
Define agonist in muscle action.
The muscle responsible for the main action
Provide an example of an agonist muscle.
Biceps brachii (elbow flexion)
Define antagonist in muscle action.
The muscle that opposes the action of the agonist
Provide an example of an antagonist muscle.
Triceps brachii (elbow extension)
Define synergist in muscle action.
Muscles that assist the agonist in performing a movement
Provide an example of a synergist muscle.
Brachialis (assists biceps brachii in elbow flexion)
What is the role of a fixator muscle?
Stabilizes a joint, allowing the agonist to act more effectively
Provide an example of a fixator muscle.
Rhomboids (stabilizing the scapula during arm movements)
In the head/neck, what is the agonist for neck flexion?
Sternocleidomastoid
In the head/neck, what is the antagonist for neck flexion?
Trapezius
In the head/neck, what is the synergist for neck flexion?
Scalenes
In the upper extremities, what is the agonist for elbow flexion?
Biceps brachii
In the upper extremities, what is the antagonist for elbow flexion?
Triceps brachii
In the upper extremities, what is the synergist for elbow flexion?
Brachialis
In the trunk, what is the agonist for trunk flexion?
Rectus abdominis
In the trunk, what is the antagonist for trunk flexion?
Erector spinae
In the trunk, what is the synergist for trunk flexion?
External obliques
In the lower extremities, what is the agonist for knee extension?
Quadriceps femoris
In the lower extremities, what is the antagonist for knee extension?
Hamstrings
In the lower extremities, what is the synergist for knee flexion?
Sartorius
What cellular change occurs in the muscular system due to resistance training?
Hypertrophy from increased protein synthesis
What is a gross anatomical change in the muscular system caused by exercise?
Increased muscle mass, tone, and strength of tendons and ligaments
What cellular change occurs in the muscular system due to aging?
Sarcopenia (muscle loss) from decreased protein synthesis
What is a gross anatomical change in the muscular system caused by aging?
Reduced muscle mass and stiffer muscles
Define strain.
Injury to muscle or tendon caused by overstretching or tearing
What are common symptoms of a strain?
Pain, swelling, weakness, muscle spasms, limited range of motion
What is the treatment for a strain?
Rest, ice, compression, elevation, or physical therapy
Define sprain.
Ligament injury caused by overstretching or tearing of ligament fibers
What are common causes of a sprain?
Twisting or stretching joint beyond normal range of motion
What are common symptoms of a sprain?
Pain, swelling, bruising, and joint instability
What is the treatment for a sprain?
R.I.C.E and sometimes surgical intervention
What are prevention strategies for strains and sprains?
Warm-up and stretching, correct posture, strength and flexibility training
bisphosphonates
examples: i.e. alendronate, risedronate, zoledronic acid. inhibit osteoclast-mediated bone resorption by binding to hydroxyapatite in bone, causing osteoclast apoptosis. Increases bone mineral density by reducing bone loss. Decreases fracture risk. Reduces bone remodeling rate and can increase the risk of atypical femoral fracture or osteonecrosis of the jaw in the long term due to oversuppression of bone turnover. Can indicate osteoporosis, Paget’s disease of bone, and prevention of fratures in high-risk patients
denosumab (prolia)
monoclonal antibody that inhibits RANKL to prevent its interaction with RANK receptors on osteoclasts and inhibit osteoclast formation. Decreases bone resorption, increases bone density, reduces risk of fractures, and returns to normal when use is discontinued. Used with osteoporosis, treatment of bone loss associated with cancer, and prevention of skeletal-related events
skin tone
pigmented by the amount of melanin in skin, hereditary, is affected by the sun, smoking, medications, skin conditions, hormones and aging
appearance and texture changes of skin
skin blotches (dyschromia), like brown spots, redness, broken blood vessels, UV exposure, & aging. Textural changes from dryness, the formation of scales, and benign & precancerous growths
aging
wrinkles, less collagen, spotted skin, loss of subcutaneous support
elastin
stretchy protein that is in skin, major component in dermis, lungs, bladder, and blood vessels. Many large, flexible molecules called tropoelastin join together to form elastin. The main amino acids that make up elastin are proline, glycine, desmosine and isodesmosine.
collagen
provides structure, strength, and support to the body and connective tissue. Collagen accounts for 30% of your body’s protein. The main amino acids that make collagen are proline, glycine and hydroxyproline in a triple helix structure. Forms fibroblasts in the dermis, helps blood clot, protects organs
birthmarks
areas of discolored and/or raised skin that are apparent at birth or within a few weeks of birth, usually benign.
fingerprints
form around 17-19 gestational weeks, amniotic fluid, fetus size, & location affects fingerprints. Fingerprints help grab objects and increase tactile sensation.
calluses
thick skin for protection, usually caused by friction, external factors, and can sometimes become ulcers.
bone minerals
mostly hydroxyapatite (Ca10(PO4)6(OH)2) for hardness and strength. Also includes calcium, phosphorus, and strontium for strength; magnesium, fluoride, and zinc for formation, and sodium and potassium for maintaining balance
long bones
(longer than they are wide, function in support and movement e.g. femur, humerus, tibia)
short bones
(cube-shaped, provide stability with limited movement e.g. wrist and ankle bones—carpals and tarsals),
flat bones
(broad thin shape, protection and muscle attachment, two layers of compact bone with spongy bone sandwiched in between, e.g. skill, ribs, sternum, scapula)
irregular bones
(complex shape with specialized function e.g. vertebrae, sphenoid bone),
sesamoid bones
(small, round, reduce friction within tendons, e.g. patella/kneecap)
open (compound) fracture
The bone pokes through the skin and can be seen or a deep wound exposes the bone
closed (simple) fracture
The bone is broken, intact skin.
transverse fracture
(straight break across bone from perpendicular trauma)
oblique fracture
(diagonal break across bone from angled blow/rotational force)
spiral fracture
(helix-patterned breakage from twisting injuries often in long bones),
comminuted fracture
(shatters into 3+ pieces, high-impact trauma),
segmental fracture
(breakage in two places creating free-floating segment in the middle)
greenstick fracture
(incomplete fracture—bend on one side, breakage on the other)
buckle/torus fracture
(buckles, doesn’t break)
avulsion fracture
(bone fragment pulled away by tendon or ligament),
impacted fracture
(fragments driven into each other)
stress/hairline fracture
(crack from repetitive stress in weight-bearing bones)
pathologic fracture
(break in weakened bone due to underlying disease; osteoporosis or cancer)
compression fracture
(pressure-induced bone collapse, often in spine due to osteoporosis)
muscle contraction physiology
ACh released at neuromuscular junction by motor neuron causing action potential in fiber that travels along sarcolemma into T-tubules to trigger calcium ion release by the sarcoplasmic reticulum. Calcium binds to troponin on acting filaments causing a conformational change to expose myosin binding site where myosin heads bind to actin to form cross-bridges and then pivot to pull actin filaments toward center of sarcomere to shorten muscle (sliding filament theory). ATP binds to myosin and causes it to detach from actin before myosin is re-cocked for another cycle through ATP hydrolysis.
muscle relaxation physiology
calcium ions are actively transported back into the sarcoplasmic reticulum. with decreased calcium, troponin and tropomyosin return to their resting state, covering the myosin-binding sites on actin. without cross-bridge formation, the muscle relaxes and returns to its resting length.
actin filaments
(in bone-forming and bone-resorbing cells that help with shape, adhesion, and movement)
collagen filaments
(type I collagen, form structural framework of bone matrix, provide tensile strength, and are a scaffold for mineral deposition.
sarcolemma
special membranes of muscle cells that enclose the cytoplasm (a.k.a sarcoplasm) and transmits electrical signals for contraction
sarcolemma depolarization
happens when an action potential is initiated through ACh release that causes calcium release and contraction
cutaneous immune system
defends the skin, body’s first barrier against external pathogens
keratinocytes (immune defense)
predominant cell type in the epidermis. Produce cytokines and antimicrobial peptides for immune defense
langerhans cells
epidermal dendritic cells, primary antigen-presenting cells in the skin that capture foreign antigens through dendritic processes and migrate to nearby lymph nodes to present the antigens to naive T cells for an adaptive immune response.
dermal dendritic cells
reside in the dermis and are involved in immune surveillance and antigen presentation. They capture and process antigens and can activate T cells
dermal macrophages
abundant in the dermis and work to phagocytose pathogens, dead cells, and debris. Produce inflammatory cytokines in response ot infection which recruits additional immune cells to the site of infection
T cells
secrete cytokines that activate other immune cells, kill infected or malignant cells
mast cells
found in the dermis, play a role in allergic reactions and defense against parasites
neutrophils
granulocytes involved in the initial immune response to infections. Work by phagocytosing pathogens and secreting antimicrobial substances such as ROS and proteases
eosinophils
involved in immune responses against parasitic infection and allergic conditions such as eczema or atopic dermatitis. Release toxic granules containing proteins like MBP to damage pathogens
fibroblasts
they can secrete cytokines and growth factors to regulate inflammation and promote tissue repair
endothelial cells
regulate the migration of immune cells into tissues. Express adhesion molecules that mediate extravasation to allow immune cells to exit the bloodstream and enter injurious areas
phosphocreatine system (ATP-CP system)
primary energy source for short bursts of intense activity like sprinting or heavy lifting. PCr stored in muscle cells donates phosphate group to ADP to quickly regenerate ATP. reaction is catalyzed by creatine kinase and results in creatine + ATP. provides energy for about 10-15 seconds of maximal activity with rapid ATP regeneration and not requiring oxygen (anaerobic). Phosphocreatine stores are limited and deplete rapidly
glycogen storage
glycogen in the main stored form of glucose in skeletal muscles consisting of branched chains of glucose molecules, stored in muscle fibers and liver and used for muscle contraction.
anaerobic glycolysis
rapid energy production in the absence of oxygen where glycogen becomes glucose, then pyruvate, then lactate, which can later be converted back to glucose via the Cori cycle
aerobic glycolysis
long-duration energy production with oxygen which is when glycogen becomes glucose, then pyruvate, then acetyl-CoA, then citric acid cycle, then electron transport chain. Occurs during moderate to low-intensity actiivty, more efficient and yields 36-38 ATP per glucose molecule and produces water and carbon dioxide as byproducts
