Human Anatomy and Physiology: Intro

• Introduction to Human Anatomy & Physiology covers topics like homeostasis, levels of organization, body organization, and anatomical terms.
• Physiology is the study of the normal functioning of a living organism and its component parts.
• Anatomy is the study of structure.
• Key characteristics of life include responding to the environment, growth and development reproduction of offspring, heredity of traits, metabolism for energy, cellular structure and composition, and homeostasis for stable inner conditions.
• Levels of organization in the body go from atoms to molecules to cells to tissues to organs to organ systems to organisms to populations of one species to ecosystems of different species to the biosphere
• Body systems are integrated.

Homeostasis

• Homeostasis is the ability to maintain a relatively constant internal environment.
• Variables like body temperature, fluid balance, and blood sugar are maintained by living systems.
• When blood glucose levels rise, the pancreas releases insulin, body cells take up glucose, and the liver takes up glucose and then blood glucose levels decline, which keeps it within the range for homeostasis.
• The homeostatic response loop involves a stimulus that produces a change in a variable, which is then detected by a receptor.
• Information is sent along an afferent pathway to a control center.
• Output from the control center is sent along an efferent pathway to an effector.
• The effector's response feeds back to influence the magnitude of the stimulus, returning the variable to homeostasis.
• Feedback loops modulate the response loop; these can be negative or positive.
• A negative feedback loop shuts off the response loop, unlike positive feedback.
• In a positive feedback loop, the variable being regulated is sent further from its normal value.
• During labor, as the baby drops lower in the uterus, it initiates labor and causes cervical stretch from the baby pushing against the cervix.
• Cervical stretch stimulates oxytocin release, causes uterine contractions, and pushes the baby against the cervix further.
• Delivery of the baby stops the cycle.
• Body temperature is maintained by the hypothalamus.
• The hypothalamus detecting deviations signals effector organs.
• Thermoreceptors send signals to the control center.
• An example of stimulus is when body temperature rises above normal.
• This also occurs when body temperature drops below normal.
• Skin blood vessels dilate, and sweat glands secrete.
• Body heat is lost to surroundings, and temperature drops toward normal.
• This generates muscle activity and conserves body heat.

Anatomical Terms

• Anatomical terms assume the body is in a standard position called the anatomical position.
• In anatomical position, the body is erect with the feet parallel, and the arms hanging at the sides with the palms facing forward.
• Relative Positions:
  • Superior: above
  • Inferior: below
  • Anterior (ventral): towards the front
  • Posterior (dorsal): towards the back
  • Medial: toward the midline
  • Lateral: away from the midline
  • Intermediate: between medial and lateral
  • Proximal: closer to the origin of the body part
  • Distal: farther from the origin of the body part
  • Superficial: toward or at the body surface
  • Deep: away from the body surface.
• Terms of Laterality:
  • Unilateral: One side
  • Bilateral: Two Sides
  • Ipsilateral: Same Side of Body
  • Contralateral: Opposite Side of Body
• Body Sections:
  • Sagittal: divides the body into left and right parts
  • Transverse (horizontal): divides the body into superior and inferior parts
  • Coronal (frontal): divides the body into anterior and posterior parts
  • Cross Section: cut perpendicular to the longitudinal axis
  • Oblique Section: cut at an angle
  • Longitudinal Section: cut along the long axis

Body Regions

• Cephalic (head), Frontal (forehead), Orbital (eye cavity), Nasal (nose), Buccal (cheek), Oral (mouth), Mental (chin), Cervical (neck)
• Acromial (point of shoulder) , Axillary (armpit
• Sternal, Pectoral (chest
• Brachial (arm)
• Antecubital (front of elbow)
• Abdominal (abdomen)
• Umbilical (navel), Inguinal (groin), Coxal (hip), Manus (hand)
• Antebrachial (forearm), Carpal (wrist), Palmar (palm), Digital (finger)
• Pubic (genital)
• Patellar (front of knee), Crural (leg), Pedal (foot)
• Tarsal (instep)

Posterior Body Regions

• Occipital (back of head)
• Acromial (point of shoulder)
• Vertebral (spinal column), Brachial (arm), Dorsum (back), Cubital (elbow), Manus (hand)
• Lumbar (lower back), Sacral (between hips), Gluteal (buttocks), Perineal, Femoral (thigh)
• Popliteal (back of knee), Crural (leg), Pedal (foot), Plantar (sole)

Body Cavities

• Dorsal body cavity contains cranial and spinal cavities.
• Ventral body cavity contains thoracic cavity (pleural and pericardial) and abdominopelvic cavity.
• Thoracic & Abdominopelvic Membranes:
  • Serosa or Serous membranes have serous fluid.
  • Plural membrane, pericardial membrane, and peritoneal membrane.
• Peritoneal membranes and serous membranes are in the abdominopelvic cavity.
• Abdominopelvic regions include right/left hypochondriac, lumbar, and iliac regions, along with epigastric, umbilical, and hypogastric regions.

Organ Systems

• Integumentary system includes skin, hair, nails, swear glands, and sebaceous glands.
• Skeletal system includes bones, ligaments, and cartilage.
• Muscular system includes the skeletal, cardiac, and smooth muscles.
• Nervous and Endocrine systems work on integration and coordination.
• Cardiovascular System is comprised of the heart, arteries, capillaries & veins for transport.
• Lymphatic system includes lymph vessels and nodes, thymus, and spleen for transport.
• Digestive, respiratory, and urinary systems work for absorption and excretion.
• The male and female reproductive system work for reproduction.

Introduction to Human Anatomy and Physiology covering key concepts such as homeostasis and levels of organization. It also touches on body organization and anatomical terms. Learn about the vital characteristics of life, including environmental response and metabolism.