Week 1 Intro to Anatomy and Physiology, Cells, and Homeostasis

Anatomy is the study of structure such as bones like humerus and femur
Physiology is the study of how organs work
Kinesiology is the study of body movements and mechanics
Function is related to structure; anatomy and physiology are intertwined
Example: left ventricle hypertrophy, enlargement of the left ventricle; detected on EKG or ultrasound
Heart diagram basics: atria on top, ventricles on bottom

The body is organized from the chemical level to macroscopic levels
Chemical level: atoms and molecules; organelles inside cells
Cells: basic units with organelles like nucleus and mitochondria
Tissues: groups of cells performing a similar function (eg cardiac tissue, liver tissue)
Organs: made of tissues
Organ systems: groups of organs
Organisms: whole being
Molecule defined as two or more atoms
11 organ systems correspond to weekly topics

Life requires boundaries and compartments (eg cavities such as cardiac and peritoneal cavities)
Needs to move to obtain food, respond to environment, digest and metabolize, excrete toxins, reproduce, and grow
Ability to respond and adapt to external stimuli
Metabolism: all chemical reactions in the body
Boundaries and movement enable survival in varied environments (eg altitude, pressure changes)

Homeostasis = maintenance of internal equilibrium within limits
Not 100% rest or 100% fight states; balance maintained by resting and active systems
Autonomic NS: parasympathetic = rest and digest; sympathetic = fight or flight
Breathing is modulated by environment; examples like high altitude can disrupt breathing
HAPE (high altitude pulmonary edema) as a negative impact on breathing regulation
Receptors (internal and external) detect changes; effectors enact responses
Negative feedback loops decrease a deviation (eg sweating to cool in heat)
Positive feedback loops amplify a response (eg childbirth with oxytocin causing stronger contractions)
Kidneys help maintain homeostasis by sensing needs and modulating salt and water balance via hormones like ADH and cortisol
Disruption of homeostasis can affect sleep and nighttime physiology; ultrasound can aid diagnosis

Anatomical position: body erect, feet apart, palms forward, thumbs outward
Superior vs inferior: above vs below relative to reference point
Anterior (ventral) vs posterior (dorsal): front vs back
Medial vs lateral: toward midline vs away from midline
Proximal vs distal: closer to vs farther from the trunk
Superficial: toward the surface
Axial skeleton: head, neck, trunk; appendicular: limbs
Axial develops first in development; appendicular develops later
Key regions for ultrasound labeling: nasal, orbital, frontal, mental, dental, ear, sternal, axillary, mammillary, lower limbs, sacral, lumbar, vertebral
Mammary glands present in mammals

Sagittal plane: divides body into left and right parts
Frontal (coronal) plane: divides body into front and back
Transverse plane: divides body into top and bottom
Midsagittal: plane exactly along midline; parasagittal: offset from midline
Dorsal (posterior) cavity: brain and spinal cord
Ventral (anterior) cavity: everything else; subdivided into thoracic and abdominopelvic cavities
Imaging orientation for ultrasound: planes guide where to scan (transverse, sagittal, frontal)

A cell is the structural and functional unit of life; over 250 cell types
Structure determines function (shape dictates role like neurons vs fat cells)
All cells share common features: plasma membrane, cytoplasm with organelles, nucleus in many cells
Key organelles: nucleus, mitochondria, rough endoplasmic reticulum, cytoskeleton
Plasma membrane: phospholipid bilayer with polar (hydrophilic) head and nonpolar (hydrophobic) tails
Hydrophilic heads face water; hydrophobic tails face the interior
Steroids can cross the lipid layer due to lipid solubility
Transport across membranes: active (uses energy) vs passive (no energy)
Intracellular vs extracellular material
Importance: structure equals function in everything from neurons to other cell types

A worksheet will cover identifying body parts and understanding anatomical terms on ultrasound orientation
Review will occur briefly; a study guide will be provided during the week
Quick review session planned for Wednesday
Focus on core concepts: cell structure, homeostasis, body organization, anatomical terms, and plan for body planes and cavities