Anatomy & Physiology Chapter 1

Anatomy

asks “where?” and focuses on structure

Physiology

asks “how” and focuses on function

What is the core principle connecting anatomy and physiology?

structure and function are inseparable

Alveolar

tiny air sacs located in smallest airways in the lungs

How does a structure support gas exchange?

1) Thin walls → short diffusion distance

2) Large surface area → more space for gas exchange

3) Dense capillaries → help maintain concentration gradients

What happens to gas exchange if alveolar wall thickens?

gas exchange becomes less efficient because diffusion distance increases

Capillary

smallest blood vessels in the human body

List the levels of organization in order

chemical → cell → tissue → organ → organ system → organism

Cells

specialized by gene expression and shape

Four primary tissues

epithelial, connective, muscle, and nervous tissue

Organs

two or more tissue types form a functional unit

11 Organ Systems

1) Integumentary (skin)

2) Skeletal

3) Muscular

4) Nervous

5) Endocrine (hormones)

6) Cardiovascular

7) Respiratory

8) Digestive

9) Lymphatic/Immune

10) Urinary

11) Reproductive

System principle

no organ works alone

Integumentary (Skin) System

barrier, temperature control, sensation (ex. skin, hair, nails)

Skeletal System

support, protection, mineral storage (ex. bones, cartilage, ligaments)

Muscular System

movement, posture, heat production (ex. skeletal muscles, tendons)

Nervous System

rapid control and communication (brain, spinal cord, nerves)

Endocrine (hormone) System

long-term control through hormones (pituitary, thyroid, adrenal glands)

Cardiovascular System

gas exchange and acid-base balance (ex. airways, lungs)

Digestive System

breaks down food and absorbs nutrients (ex. GI tract, liver, pancreas)

Lymphatic/Immune System

returns tissue fluid and defends against pathogens (ex. lymph nodes, spleen, lymph vessels)

Urinary System

removes nitrogenous wastes; regulates water, ions, and pH (ex. kidneys, ureters, bladder)

Reproductive System

produces gametes and sex hormones; supports development (ex. ovaries/testes, associated organs)

Homeostasis

keep variables within a functional range

Examples of homeostasis

body temperature, blood glucose, blood pressure, pH, and O₂/CO₂

Negative feedback

reverses/counteracts a change

Positive feedback

amplifies a change usually toward completion

What are the three homeostatic control components emphasized?

1) Receptor

2) Control center

3) Effector

Receptor

detects a change

Control center

processes information and coordinates the response

Effector

carries out the response

Explain the process of homeostasis

Change → Receptor → Control center → Effector → Response (negative/positve)

Explain the blood glucose example for negative feedback (counteracts)

Blood glucose rises → pancreas senses the change → insulin is released → cells take up glucose → blood glucose falls

Explain the childbirth example for positive feedback (amplifies)

cervical stretch → oxytocin (triggers contractions) → stronger contractions → more stretch

Explain the blood-clotting example for positive feedback (amplifies)

activated platelets recruit more platelets until the break is sealed

What is the common reference for anatomical positions for the body?

• Standing upright

• Head and eyes forward

• Arms to the sides

• Palms face forward

• Feet flat and forward

Superior

above (ex. heart is superior to the diaphragm)

Inferior

below

Medial

toward midline (ex. nose is medial to eyes)

Lateral

away from midline

Anterior

front (ex. sternum—breastbone—is anterior to the heart)

Posterior

back

proximal

near point of attachment (ex. elbow is proximal to wrist)

distal

farther point of attachment

Superficial

nearer to surface (ex. skin is superficial to skeletal muscle)

Deep

farther from surface

Sagittal

left and right portions

Midsagittal

equal left and right halves

Frontal/Coronal

anterior and posterior portions; front and back

Transverse

superior and inferior portions; cross-section

Oblique

cut at an angle; not aligned to major planes

Ventral cavity (front)

thoracic + abdominopelvic cavities; houses the viscera

Dorsal cavity

cranial + vertebral cavities; protects the central nervous system

Diaphragm

separates thoracic and abdominopelvic cavities

Pleura

surrounds the lungs

pericardium

surrounds the heart

peritoneum

lines abdominopelvic cavity

Viseral

touches the organ

Parietal

lines the cavity wall

What separates the thoracic and abdominopelvic cavities?

the diaphragm

What does the pleura surround

the lungs

What does the pericardium surround?

the heart

What does the peritoneum line surround?

the abdominopelvic cavity

What’s the difference between visceral and parietal?

visceral touches the organ; parietal lines the cavity wall

Which is faster for clinical abdominal location?

quarants are faster; nine regions are more precise

Why is system thinking important?

physiological responses are usually coordinated across the whole body

Right Upper Quadrant (RUQ)

• Liver

• Gallbladder

• First part of the small intestine

• Head of pancreas

• Right kidney and adrenal gland

• Parts of the large and small intestine

Left Upper Quadrant (LUQ)

• Stomach

• Spleen

• Left kidney and adrenal gland

• Body and tail of the pancreas

• Part of the liver

• Parts of the large and small intestines

Right Lower Quadrant (RLQ)

• Appendix

• Start of the large intestine

• Right ureter

• Right reproductive organs

• Parts of the small intestine

Left Lower Quadrant (LLQ)

• Sigmoid colon

• Left ureter

• Left reproductive organs

• Parts of the small intestine

Epigastrium (center)

• Stomach

• Pancreas

• Duodenum

Umbilical (belly button)

• Aorta

• Pancreas

• Small intestine

Suprapubic

• Urinary bladder

• Uterus

Hypochondriac Region

Upper left or right region, under the ribs

Lumbar Region

Middle side section, located on left or right side of the umbilical (navel/belly-button) region

Iliac Region

Lower section, left or right of the abdomen