A&P Chapter 1 🧍🏻

Anatomy

The study of structure of body parts and their relationships to one another

Physiology

The study of function, the body’s structural machinery

How do physicians study patients?

• Inspection: Inspecting the body with the naked eye

• Palpation: Touching/feeling different parts of the body

• Auscultation: Listening to blockages or fluid in inside the body (lungs, stomach)

• Percussion: Tapping part of the body as part of diagnosis

Types of Anatomical Study

• Gross or Macroscopic

• Cadaver Dissection

• Microscopic

Histology

The study of tissues

Cytology

The study of cells

Subdisciplines of Anatomy

• Pathological Anatomy: study of structural changes caused by disease

• Radiographic Anatomy: Study of internal structures using medical imaging techniques

• Molecular Biology: Study of anatomical structures at a subcellular level

What is the relationship between anatomy and physiology?

Structure always reflects function and vice versa

The inductive method

• Observational: Making numerous observations until drawing a conclusion

• Proof in science: Reliable observations, repeatedly confirmed.

• Not falsified by any credible observation

• Truth is tentative

Hypothetico-Deductive Method

• A hypothesis is formed, consistent with what is already known + can be tested

• Falsifiability: Ability to specify what would prove a claim wrong

Experimental Design

• Sample size: # of subjects in a study

• Controls: Control group does not receive treatment

• Psychosomatic effects: effects of subjects state of mind on their biology. Placebo given to control group

• Experimenter bias: Double-blind study

• Statistical testing: Provided statement that treatment was effective

Necessary life functions

• Responsiveness: Ability to sense changes in environment + respond

• Digestion: breakdown of ingested food

• Metabolism: chemical reactions that occur in the body

• Excretion: removal of waste from the body

• Reproduction: (Cellular & Organismal)

• Growth: Increase in size of body part/organism

Survival Needs

• Nutrients: energy + cell repair

• Oxygen: metabolic reactions

• Water: necessary environment for chemical reactions

• Normal BT: for chemical reactions at life sustaining rates

• Atmospheric Pressure: proper breathing + gas exchange

Homeostasis

Ability to maintain a stable internal environment despite external changes

Homeostatic Control Mechanisms

Variables produce change in the body

• Receptor/Senser: Monitors environment + responds to stimuli (changes)

Ex. Thermometer detects drop in temperature

• Control center: Determines the set point at which variable is maintained

Ex 2. Thermostat controls heat setting

• Effector: provides the means to respond to stimuli

Ex 3. Heater balances temperature

Negative Feedback

Output shuts off original stimulus

Feedback loop

Feedback mechanisms altering the original changes that triggered them, causing a loop

Homeostasis in body temperature

• Too warm: blood vessels dilate; Sweating decreases BT

• Too cold: blood vessels constrict; Shivering increases BT

Positive Feedback

Output enhances or exaggerates original stimulus

Hierarchy of Complexity (smallest to largest)

• Molecules

• Organelles

• Cells

• Tissues

• Organs

• Organ Systems

• Organisms

Anatomical Variation

No two humans are exactly alike

• Variable # of organs

• Variation in organ location

Physiological Variation

• Sex, age, diet, weight, physical activity

Female & Male references

• 22 yrs old

• Light physical activity

• (F): 128lbs/58kg, 2,000 kcal/day

• (M): 154lbs/70kg 2,800 kcal/day

Anatomical Position

• Body erect

• Feet slightly apart

• Palms facing forward

• Thumbs pointing away from body

Superior

Toward the head or upper part of of a structure or the body; above

Ex. The head is [________] to the abdomen

Inferior

Away from the head end or toward the lower part of the structure or the body; below

Ex. The navel is [________] to the chin

Anterior/Ventral

Toward or in front of the body; in front of

Ex. The breastbone is [________] to the spine

Posterior/Dorsal

Toward or at the back of the body; behind

Ex. The heart is [________] to the breastbone

Medial

Towards the midline of the body

Ex. The heart is [________] to the arms

Lateral

Away from the midline of the body

Ex. The arms are [________] to the chest

Intermediate

Between a more medial and a more lateral structure; in between

Ex. The collarbone is [________] between the breastbone and shoulder

Proximal

Closer to the body trunk

Ex. The shoulder is [________] to the wrist

Distal

Farther from the body trunk

Ex. The knee is [________] to the thigh

Superficial/External

Toward or at the body surface

Ex. The skin is [________] to the muscles

Deep/Internal

Away from the body surface; more internal

Ex. The lungs are [________] to the skin

Sagittal

Plane that divided the body into RIGHT and LEFT parts

Midsagittal/Medial

Sagittal plane that lies on the midline

Frontal/Coronal

Divides the body into ANTERIOR and POSTERIOR parts

Transverse/Horizontal

Divides the body into SUPERIOR and INFERIOR parts

Oblique Section

Cuts made diagonally /

Dorsal Cavity

• Cranial cavity: within the skull, encases the brain

• Vertebral cavity: runs within the vertebral column, encases the spinal cord

Ventral Cavity

• Thoracic cavity: Contains heart and lungs

• Abdominopelvic cavity:

  (Abdominal cavity) contains digestive viscera,

  (Pelvic cavity) contains bladder, reproductive organs, and rectum

Abdominopelvic Regions (from front view, right to left)

1. Right hypochondriac region

2. Epigastric region

3. Left hypochondriac region

4. Right lumbar region

5. Umbilical region (bellybutton)

6. Left lumbar region

7. Right inguinal region

8. Hypogastric region

9. Left inguinal region

Organs of the abdominopelvic region

1. Right hypochondriac region: liver, gallbladder

2. Epigastric region: stomach

3. Left hypochondriac region: diaphragm (?)

4. Right lumbar region: Ascending colon of large intestine

5. Umbilical region (bellybutton): small intestine

6. Left lumbar region: Descending colon of large intestine

7. Right inguinal region: Cecum

8. Hypogastric region: appendix, urinary bladder

9. Left inguinal region: initial part of sigmoid colon

Radiography (X-rays)

• Penetrate soft tissues

• Dense tissues remain white

• Can see hollow structures (intestinal tract, DSA blood vessels)

Radiopaque substances are injected or swallowed

Computed Tomography (CT Scan)

• low-intensity x-rays and computer analysis

• Increased sharpness

Magnetic Resonance Imaging (MRI)

• Best for soft tissue

• Can see through the skull & spine

• Mechanics for MRI:

Magnetic field aligns atoms

Radio waves REALIGN atoms

Radio turned off

Atoms realign to MAGNETIC FIELD

Energy given off depending on tissue type

Positron Emission Tomography (PET Scan)

• Assesses metabolic state

• Mechanics of PET:

Inject labeled glucose (goes to all cells that use energy)

Positrons & electrons collide, gamma rays given off

Analyzed by computer

Image of glucose (energy) usage

Sonography

• Second oldest + second most widely used

• Mechanics of sonography:

High frequency sound waves echo back from internal organs

• Avoids harmful x-rays

(Obstetrics/Sonograms)

Image not very sharp

Integumentary System

• Forms external covering of the body

• Composed of skin, hair, nails, sweat glands & oil glands

• Protects deep tissue from injury + synthesizes vitamin D

Skeletal System

• Composed of bone, cartilage & ligaments

• Protects & supports body organs

• Provides framework for muscles

• Sit of blood cell formation

• Stores minerals

Muscular System

• Composed of muscles & tendons

• Allows manipulation of environment, locomotion (movement), & facial expression

• Maintains posture

• Produces heat

Nervous System

• Composed of the brain, spinal column, & nerves

• Is the fast-acting control system of the body

• Responds to stimuli by activating muscles & glands

Cardiovascular System

• Composed of the heart & blood vessels

• The heart pumps blood

• Blood vessels transport blood throughout the body

• Distributes oxygen

Lymphatic System

• Composed of red bone marrow, thymus, spleen, lymph nodes, & lymphatic vessels

• Picks up fluid leaked from blood vessels & returns it to blood

• Disposes of debris in the lymphatic system

• Houses white blood cells

Respiratory System

• Composed of the nasal cavity, pharynx, trachea, bronchi, & lungs

• Keeps blood supplied with oxygen

• Removes carbon dioxide

Digestive System

• Composed of oral cavity, esophagus, stomach, liver, small intestine, large intestine, rectum & anus

• Breaks down food into absorbable units that enter blood

• Eliminates indigestible foodstuffs

Urinary System

• Composed of kidneys, ureters, urinary bladder, & urethra

• Eliminates nitrogenous waste

• Regulates water, electrolyte, & pH balance of the blood

Endocrine System

• Composed of hypothalamus, pituitary gland, pineal gland, thyroid gland, adrenal glands, pancreas, gonads

• Produces hormones to coordinate metabolic processes; growth, metabolism, reproduction

Male Reproductive System

• Composed of prostate gland, penis, testes, scrotum, & ductus deferens

• Main function: production of offspring

• Testes produce sperm + make sex hormones

• Ducts & glands deliver sperm to the female reproductive tract

Female Reproductive System

• Composed of mammary glands, ovaries, uterine tubes, uterus, & vagina

• Ovaries produce eggs + female sex hormones

• Remaining structures serve as sites for fertilization & fetus development

• Mammary glands produce milk to nourish newborn

How are organ systems interrelated?

• Nutrients & oxygen are distributed by the blood

• Metabolic wastes are eliminated by the urinary & respiratory systems