Human Body and Clinical Applications Lecture Notes Review

Comprehensive practice flashcards covering cell biology, human anatomy, physiological systems, and clinical imaging applications as discussed in the lecture transcript.

According to the lecture, what are the three basic components of a cell?

Protoplasm (watery material containing organelles), Plasma membrane (cell wall), and the Nucleus (command centre).

What is the primary role of mitochondria in the cell ecosystem?

They are the double-membraned powerhouses responsible for ATP production through oxidative phosphorylation.

How do lysosomes facilitate their role as the cellular recycling centres?

They contain over $60$ hydrolytic enzymes optimised for acidic conditions ($pH 4.5-5.0$) to break down worn-out organelles, proteins, and lipids.

Approximately what percentage of cellular ATP production is consumed by active transport systems?

Approximately $25\%$, highlighting their importance in maintaining homeostasis and electrochemical gradients.

What are the three distinct phases of the glucose breakdown pathway used to generate ATP?

Glycolysis, the Krebs Cycle, and Electron Transport.

How does ${^{18}F}$-fluorodeoxyglucose (FDG) behave once it enters a cell during a PET scan?

It behaves like glucose but changes into FDG-6-phosphate, which cannot proceed further in glycolysis and becomes trapped, allowing for metabolic visualisation.

What are the four primary tissue types that form the building blocks for organs?

Epithelial Tissue, Connective Tissue, Muscle Tissue, and Nervous Tissue.

In the biological hierarchy, what level is defined as a combination of different tissue types working together to perform specific physiological functions?

Level 3: Organs.

What anatomical plane divides the body into superior (upper) and inferior (lower) portions?

The Transverse (Axial) Plane.

What is the definition of the directional term 'Proximal' in the context of the appendicular skeleton?

Closer to the point of attachment or origin.

What occurs when positrons encounter electrons during a PET scan process?

Annihilation occurs, resulting in the emission of two gamma rays ($0.511\,Mev$ photons) at $180^{\circ}$ to each other.

What does the Standardised Uptake Value (SUV) measure in quantitative PET analysis?

It normalises tracer concentration for patient weight and injected dose, allowing for quantitative comparison across patients and time points.

Which PET tracer is specifically mentioned for tracking amino acid uptake and protein synthesis in brain tumour imaging?

${^{11}C}$-Methionine.

What are the three distinct layers of the integumentary system's architecture?

The superficial epidermis, the intermediate dermis, and the deep hypodermis.

What are the five distinct layers of epidermal stratification from outermost to innermost?

Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, and Stratum Basale.

What is the primary function of the Reticular Dermis layer?

It provides mechanical support, thermoregulation, secretory functions (via glands), and deep pressure sensation.

What photochemical process involving the skin allows the body to synthesise Vitamin $D_3$?

UVB radiation ($280-320\,nm$) converts 7-dehydrocholesterol in basal keratinocytes to previtamin $D_3$, which then undergoes thermal isomerisation.

What is 'holocrine secretion' in the context of sebaceous glands?

A process where entire cells (sebocytes) disintegrate to release sebum, a lipid-rich cocktail of triglycerides, fatty acids, and cholesterol esters.

Which cutaneous sensory receptor is responsible for detecting deep pressure and high-frequency vibrations?

Pacinian corpuscles.

What are the four phases of the wound healing and regeneration process described in the lecture?

Haemostasis ($0-1$ day), Inflammation ($1-4$ days), Proliferation ($4-21$ days), and Remodelling ($21$ days - $2$ years).

Describe the structural difference between Compact bone and Cancellous bone.

Compact bone is a calcified matrix with Haversian canals for nutrient access, while Cancellous (trabecular) bone is a lattice of tiny spikes filled with red marrow.

Which bone cells are responsible for depositing new bone matrix and which are responsible for bone resorption?

Osteoblasts deposit new bone; Osteoclasts absorb/resorb bone.

How is the adult human skeleton divided into two main divisions?

The Axial skeleton ($80$ bones providing central support) and the Appendicular skeleton ($126$ bones enabling movement).

What are the three structural classifications of joints mentioned in the hierarchy?

Fibrous, Cartilaginous, and Synovial.

What are the repeating functional units within a muscle myofibril called, and what two filaments do they contain?

Sarcomeres; they contain myosin (thick filaments) and actin (thin filaments).

What is the 'Sliding Filament Model' of muscle contraction?

A process where actin and myosin filaments slide past each other, powered by ATP hydrolysis and regulated by calcium availability, to reduce sarcomere length.

What is the physiological foundation for radiopharmaceutical uptake in bone scintigraphy (bone scans)?

Osteoblastic activity (the cellular process of new bone formation) where ${^{99m}Tc}$-diphosphonates adsorb onto hydroxyapatite crystals.

Which part of the brain is responsible for relaying sensory impulses to the cerebrum and regulating sleep?

The Thalamus.

What structures form the Protective Blood-Brain Barrier (BBB)?

Tight junctions between endothelial cells and astrocyte end-feet.

What is the function of the Basal Ganglia nuclei?

They inhibit muscle contraction, suppress unwanted movement, and coordinate sustained muscle contraction for smooth movement.

What are the three components of the brainstem, and what is the primary role of the Medulla Oblongata?

Midbrain, Pons, and Medulla Oblongata; the Medulla is responsible for decussation (nerve crossing) and basic reflex centres like cardiac and respiratory functions.

What three membranes constitute the meninges surrounding the Central Nervous System?

Dura mater (outer layer), Arachnoid Mater, and Pia mater.

What values represent the resting state and the action potential threshold in a neuron?

Resting state is $-70\,mV$; depolarization reaches a threshold of approximately $+30\,mV$.

Which major ascending nerve pathway is responsible for fine touch, proprioception, and vibration?

The Dorsal Column-Medial Lemniscal pathway.

In the eye's optical system, which part acts as the primary refractive surface?

The Cornea.

What is the 'Organ of Corti' inside the cochlea?

An epithelium containing hair cells that convert mechanical vibrations into electrical neural signals for hearing.

What are the five categories of taste detected by gustatory cells?

Sweet, Sour, Salty, Bitter, and Umami.

What EEG wave pattern is dominant during relaxed wakefulness with the eyes closed?

Alpha waves ($8-13\,Hz$).

How does functional MRI (fMRI) utilize the BOLD signal to map brain function?

It detects neuronal activity by measuring haemodynamic responses; specifically, reduced deoxyhaemoglobin at active sites creates increased MRI signal intensity.

Which PET tracers are used to visualize amyloid-β plaques and neurofibrillary tangles in Alzheimer's disease?

Amyloid tracers (e.g., ${^{18}F}$-florbetapir) and Tau tracers (e.g., ${^{18}F}$-flortaucipir).