Physiology Exam Questions

Animal Structure and Function (Lecture 9)

• Biological Organization: Animals are organized into different levels
• Tissue Types:
• Muscle tissue is for movement
• Nervous tissue is for signaling
• Epithelial tissue is for protection
• Connective tissue is for support
• Homeostasis: Utilizes positive and negative feedback loops.
• Epithelial cells: Densely packed and specialized for protection, secretion, and absorption
• Connective tissues: Connect, surround, anchor, support, attach, and allow communication between cells and tissues
• Muscle tissues: Specialized for contraction and force generation for body movement
• Nervous tissues: Initiate or conduct electrical signals between body parts
• Negative Feedback Loop: Regulates activity by using its output, like maintaining body temperature
• Example of Negative Feedback: Sweating and blood vessel dilation in response to heat to regulate body temperature
• Positive Feedback Loops: Amplify a stimulus and drive the process to completion, playing a small role in homeostasis
• Example of Positive Feedback: Blood clotting where one clot leads to worsening instead of solving the issue

Excretory System (Lecture 10)

• Nitrogenous Waste: Exists in different forms, each with pros and cons
• Kidney Functions: Include filtration, reabsorption, secretion, and excretion
• Nephron Structure: Specific parts are involved in urine formation
• Ion Movement: Based on concentration gradients

Excretory System (Continued) (Lecture 11)

• ADH Function: Plays a role in urine composition

Muscular System (Lecture 12)

• Types of Muscle Tissue: Three different types with varied locations
• Muscle Structure: From overall muscle to sarcomere level
• Contraction Mechanism: Sliding filament mechanism enables muscle contraction
• Regulation: Tropomyosin, troponin, myosin, and actin all play a regulatory role

Neuromuscular Junction (Lecture 13)

• Components: Includes structural features of the neuromuscular junction
• Acetylcholine and Calcium: Both play roles in contraction
• Sarcoplasmic Reticulum and T-Tubules: Have functions in muscle contraction

Sensory System I (Lecture 14)

• Sensory Receptors: Various types and functions
• Hearing and Balance: Involves complex mechanisms

Sensory System II (Lecture 15)

• Anatomy of Sensory Organs: Eyes and olfactory structures
• Signal Transduction: Eye focusing and olfactory processing are key

Reproductive I (Lecture 16)

• Sex Determination: Genetic and hormonal aspects
• Reproductive Cycles: Hormones have specific roles
• Variability in Sexual Development: DSDs, AIS, CAH discussion

Nitrogenous Waste Forms

• Ammonia:
• Very toxic
• Aquatic animals passively diffuse ammonia
• Urea:
• Toxic needs dilution
• Mammals, amphibians
• Uric Acid:
• Relatively non-toxic
• Birds, reptiles

Kidney Structure

• Renal Cortex: Outer layer with nephrons
• Cortical Nephron: Regulates water, electrolytes, and excretion in the cortex; creates H+ gradient in the outer loop of Henle
• Juxtamedullary Nephron: Reabsorbs water and solutes in the medulla; creates H+ gradient and extends into medulla
• Glomerulus: Filters blood in the nephron and collects fluids for urine creation
• Bowman's Capsule: Surrounds the glomerulus and with it forms the renal corpuscle, the origin of filtrate in the kidneys
• Blood pressure forces blood through glomerulus slits to make filtrate
• Small molecules such as water, ions, and sugars can pass through.

Proximal Tubule

• Critical reabsorption of ions, water, etc.
• H+ gradient and ammonia secretion take place
• NaCl in filtrate diffuses using transport epithelium, allowing Na+ ions into interstitial fluid by active transport and Cl- passively
• Water follows salt movement via osmosis; glucose, amino acids, K+ are transported from filtrate to interstitial fluid and then capillaries
• Balances body fluid pH, secretes H+ into the tubule lumen
• Synthesizes/secretes ammonia (NH₄⁺) as a buffer for H+; reabsorbs HCO3¯ for pH balance

Loop of Henle

• Descending Limb: Reduces filtrate volume, increases solute concentration, major site for water reabsorption
• Aquaporins make epithelial cells permeable to water, not salt/solutes, allowing water to exit by osmosis
• Interstitial fluid must be hyperosmotic for filtrate
• Ascending Limb: Major site for NaCl reabsorption
• Epithelium lacks water channels, impermeable to water
• Thick segment actively transports NaCl into interstitial fluid

Distal Tubule

• Regulates K⁺ and NaCl, and pH
• Secretes K+ and reabsorbs NaCl; regulates H+ secretion + HCO3¯ reabsorption

Collecting Duct

• Conserves water (dilute becomes concentrated) or produces dilute urine (duct absorbs salts and NaCl enters filtrate)
• When conserving water, aquaporin channels allow water to cross epithelium
• As the collecting duct traverses gradient of osmolarity the filtrate becomes concentrated losing water to the hyperosmotic interstitial fluid
• When producing dilute urine, duct absorbs salts without water, epithelium lacks aquaporin channels so NaCl goes to filtrate
• Presence of water channels controlled by hormones

ADH Role in Urine Composition

• ADH (Antidiuretic hormone) controls water reabsorption/secretion in kidneys, determining urine concentration
• Dehydration stimulates hypothalamus to signal pituitary gland to release more ADH, promoting water retention in kidneys
• ADH in blood increases aquaporin channels in collecting ducts and distal convoluted tubule, enabling more water reabsorption
• More ADH means more concentrated urine, vice versa
• Diabetes insipidus results in excessive dilute urine production, often due to insufficient ADH or aquaporin mutation

Sensory Reception

• Sensory receptors detect stimuli inside or outside the body
• Detection changes ion flow across the membrane, altering receptor potential
• Sensory Transduction: Stimulus conversion
• Strength of the stimuli

Transmission

• Sensory receptor is a neuron generating an action potential along the CNS axon
• Sensory receptor is a non-neuron conveying information to a neuron via chemical synapse which means they are slower

Perception

• The brain determines perception based on pre-made connections for stimuli

Sensory Receptors

• Mechanoreceptors: Hearing, balance, touch, stretching, motion, and pressure
• Membrane potentials altered by mutations (bending, stretching, pressure) in cytoskeleton and sensed things
• Altered membrane potentials allow for receptor potential or a hyperpolarization/depolarization and ion gradient
• Depolarization is often sent and the signal goes from resting to depolarized and then repolarization
• Touch receptors are often embedded in tissue
• Structure and location affect how the brain perceives the stimuli
• Chemoreceptor: Types detecting changes in solute concentration and others responding to glucose, oxygen, and amino acids
• Electromagnetic receptor: Light, electricity, and magnetism is used in migration
• Thermoreceptors: Detect heat and cold with some flavors activating the same receptors
• Pain receptors: Intense pressure, temperature with nociceptors detecting harmful conditions

Hearing and Balance

• Sound waves enter the pinna (ear) and passing auditory canal to hit the tympanic membrane,enter the middle ear, and go from malleus incus and stapes which hit the oval window
• There is also the eustachian tube in the middle ear that balances pressure beween the middle ear and atmosphere
• Oval window goes inot the inner ear where tubes filled with fluids such as the semicircular canals and the cochlea.

Function of Ear Parts

• Pinna + Auditory Canal: Collect sound waves and send them to tympanic membrane (it vibrates)
• Tympanic Membrane: Vibrates and sends vibrations
• Malleus : Carry vibrations
• Incus: Carry vibrations
• Stapes Vibrates: Against oval window so that pressure waves are created inside the cochlea
• Oval Window: Send vibrations
• Semicircular Canals
• Fluid filled canals connected responsible foe balance and detect head movement
• Pressure waves: push down on cochlear duct and basilar membrane + attached hair cells (causes depolarization)
• Cochlea: Fluid moves and hair cells cause the vibrations
• Round Window: Lets out vibrations
• Auditory Nerve; Connected to the organ of Corti in the cochlea which has hair cells that transport electrical signals
• There is an organ of Corti which connects with hairs that cause change in voltage with movement

Vision & Smell

• Compound Eyes: Ommatidia light detectors capture light
• Corneal and crystalline cone from ommatidium that focus the light
• Rhabdom Light
• Neurons struck by rods and cones
• These transfer info Types: ganglion cells, amacrine cells, bipolar cells, and horizontal cells:
  • Ganglion connected to nerve
  • Bipolar cells connect rod and con info
  • horizontal and amacrine cells integrate info
• Optic Disk: lack creates blindspot
• Rods and cones sense light

Rods vs Cones

• Rods more sensitive to light, cones sense color
• Feature
• Shape in the Rods: Optimize light absoroption in long slender shape
• Cone shape: fast signal in shorter fatter shape
• Outer segment in Rods: Stacked seperated membrane
• Outer Segment in Cones: Folded membrane
• Rod Sensitivity; Good vision in dim, low light conditions
• Cone Sensitivity: Lower light sensitivity high light
• Response speed rods low and signals from coverage
• Cones speed faster w each have a ganglion
• Visual Activity in detail for sense sacrifes detail with less neurons
• cones vice versa high sharp detail

Sensory Transduction

• Visual pigment (G-protein activates enzymes which hydrolyze
• In rods enzymes in the dark -sodium channels open
  • in light is reversed
• Light isomerized in the transduction
• Light creates change that activates trasnduction which activates GMP and closes sodium

The Eye

• Retina made of Rod photorecepors or cone photorecepetros
• Olfactory use chemoreception, two in epithelial has cells use have odeorant binder membrane
• Sensory transduction uses that the chemical triggers the g-protein which creates cAMP

Muscle

• Muscle fibers
• Muscle fiber and mioflibils and z lines that measure the lines
• Muscle from thick and thins
• ATPS that can control the movement
• Thins Actin sliding and contracting
• thick is constand
• crosshead pulled breaks when a new
• Actin has to propsonit binds on spots
• Nueron with a

Neuromuscular Junction (NMJ)

• chemical of neuron and fiber
• potential opens CA2+ channels
• ACH bind to create new potential

Reproduction Steps

• Androgen insensitivity syndrome -XY but are unresponsive to androgens like testosterone and can't use testoreone normal
• Congenital adrenal hyperplasia -XX but higher than usual can't external
• sex determination -XY chromosomes -SRY Gene causes ovaries
• RSPO1 pathway XX -RSPO1 on the cell for signaing for ovarian -signals for activating - catenin
• steps XY with 1 phosphorylation, SOX9 is sertioi and sexial differentiations drive secondary
• High levels of testosterone in males/ absence for females
• Hormones stimulate the pituitary releasing gonadal activity and testosterone
• Males - FSH stimulates Sertoli the LY
• Negative from hormones and cell reduces pituritary signals
• Laydig cells secrete other hormonal
• Female: Mullerian ducts (uterus & Fallopian tubes) in the absenence of AMH
• Regulated mammellial reporutrton
• GnRH released in the hypo which results in release of hormone.
• Males release and release androgens and inhibit
• Neg feedback in testosterone

These are physiology revision questions. The questions cover multiple topics. Topics include muscle contraction, kidney function, homeostasis, and urine formation.