Unit 1: Levels of Organization and Homeostasis - Anatomical Language and Histology

Anatomical Position

upright stance w/ head and eyes facing foward + arms extended at the side + palms facing foward + feet are flat on the ground, pointing forward

Superior

above a part

• ex: the nose is superior to the mouth

Inferior

below a part

• ex: the mouth is inferior to the nose

Anterior

toward the front

• ex: the anterior surface of the arm faces front

Posterior

toward the back

• ex: the posterior surface of the arm faces back

Medial

closer to the vertical midline of the body

• ex: the eyes are medial to the ears + the heart is medial to the lungs

Lateral

farther to the vertical midline of the the body

• ex: the ears are lateral to the ears + the ribs are lateral to the sternum

Proximal

closer to the point of attachment

Distal

farther to the point of attachment

• ex: the wrist is distal to the arm

ventral

pertaining to the front?

dorsal

pertaining to the back

Longitudinal cuts

Vertical cuts

Cross/Transverse Cuts

Horizontal cuts — dividing the body into top and bottom

Sagittal/medial

vertical cut down the middle + splitting body into left and right

Coronal/frontal

cuts the body into front and back

Parasagittal plane

vertical cut that is located to the left or right of the body’s midline

4 Abdominal Quadrants

You desribe the PERSON’S left or right, NOT yours when you are looking at them

• Right upper quandrant (RUQ)

• right lower quandrant (RLQ)

• Left upper quandrant (LUQ)

• left lower quandrant (LLQ)

9 Abominal Regions

1. Right hypochondriac region

2. right lumbar region

3. right iliac region

4. epigastric region

5. umbilical region

6. hypogastric region

7. left hypochondriac region

8. left lumbar region

9. left iliac region

9 Body Cavities

• Cranial cavity → brain

• vertebral cavity → spine

  • dorsal body cavity

• thoracic cavity → heart + lungs

• abdominal cavity → stomach, liver, gallbladder, pancreas, large+small intestine

• pelvic cavity → bladder, reproductive organs, and rectum

  • (abdomino-pelvic cavity)

• pleural cavity → lung

• pericardial cavity → heart

• ventral body cavity → thoracic cavity + abdomino-pelvic cavity

4 types of tissues

• Epithelial tissue

• Nervous tissue

• Muscle tissue

• Connective tissue

Epithelial Tissue Functions

covers inner and outer body + lines body cavities and organs

1. Protection → protects the tissues deeper in your body: blood vessels, muscle

2. Absorption → absorbs nutrients from the food you eat

3. Secretion → secrete enzymes, hormones, and fluids: cells in your saliva glands secrete saliva

4. Excretion → removal of waste from your body

5. Filtration → ex: cleans the air that you breathe in + filters your kidney’s blood

Epithelial Tissue Location

1. Cover body surface

2. Cover and line internal organs

3. Forms lining of body cavities

4. Composes glands

Defining Traits of Epithelial Cells

• Lack blood vessel/Line all blood vessels in your body

• Tightly packed

• Readily divide 

• Faces the free (apical → exterior of the body) surface

• Anchored by a basement membrane (that connects epithelium to connective tissue)

Layer Names to Classify Epithelial Tissue

• Simple → 1 layer + often found where absorption and filtration occur

• Stratified → multiple layers + found where protection occur

• Pseudostratified → 1 layer + cells can be diff. shapes and sizes + nuclei can be diff. heights

  • (looks multilayered, even though it is not)

Shape Names to Classify Epithelial Tissue

• Squamous → flat

  • (name means scaled) looks like fish scales

  • Nucleus = flat

  • absorption + transportation is most important here

    • (flat makes it easy for materials, like oxygen, to move across quickly to the other side)

  • (places where you lose a lot of cells, you have squamous cells b/c they’re smaller, faltter, and cheaper (take less time + energy + raw materials to make THUS making more)

• Cuboidal → cube

  • absorb nutrients + produce secretions, like sweat

  • nucleus = circle

• Columnar → tall/long + thick + look like rectangular columns

  • Nuclei = oval

Steps of Naming Epithelial Tissues

Layers THEN Shape

Nervous Tissue Functions

• send electrochemical messages between your brain, spinal cord, and the rest of your body

Nervous Tissue is made of…

• Nerve cells → conduct impulses to carry info from one part of your body to another

  • ex: telling your muscles to move

• Glial cells → support, protect, insulate nerve cells + helps remove waste and dead cells around neurons (allowing neurons to work properly)

(located in your brain, spinal cord, peripheral nerves)

Defining Traits of Nervous Tissue

• Cell body → life support – has nucleus, mitochondria, and DNA

• Dendrites → look like trees + collect signals from other cells to send back to the cell body

• Axon → long rope – carries messages to other neurons, muscles, and glands

Muscle Tissue Functions

responsible for 3 types of body movements:

• Skeletal Muscle → when muscles contract, they pull on bones or skin, causing movement

  • ex: your arm moves when your bicep muscle contracts

  • Long/cylindrical + straight/parallel cells

  • HAS striation (stripes)

  • (MULTIPLE nucleus)

• Smooth Muscle → helps move things inside your body that you CANNOT control (digestive, urinary tracts, and uterus)

  • ex: blood vessels are lined with smooth muscle, which help move blood by squeezing and relaxing the blood vessels

  • cells are packed together + tapered at the ends

  • NO stripes

  • (1 nucleus)

• Cardiac Muscle → ONLY FOUND in the heart + forms the walls of your heart

  • contracts and relaxes to push blood out of the heart and into the arteries

  • BRANCHING structure

  • HAS stripes

  • (1 nucleus)

Defining traits of Muscle Tissue

• Ability to Contract → Muscles tissue can shorten and produce movement

• Elongated Cells → need for contraction, increased force production and transmission

Connective Tissue Functions

• Support and Structure → support and maintain the shape of various body parts

  • ex: bones provide a rigid framework for the body — helps us stand upright and move

• Protection → protects vital organs and structures

  • ex: rib cage (made of bones) protects the heart and lungs

• Binding and Connecting → Connective tissue binds diff. parts of the body together

  • ex: Tendons connect muscles to bones + ligaments connect bones to each other (allowing for stable and coordinated movements)

• Transportation → Blood transports essential substances like oxygen, nutrients, and hormones through the body + helps remove waste products

• Storage → stores important substances

  • ex: bone tissue stores minerals like calcium and phosphorus

• Produce blood cells → bone marrow, is responsible for producing blood cells in the body

Defining Traits of Connective Tissue

• cells are spaced apart and embedded in an extracellular matrix → fluid, gel-like, or solid + makes up significant portion of the tissue’s volume

  • ex: Extracellular matrix in ligaments have elastic fibers that allow for stretching and recoil

• contains fixed or wandering cells

  • fixed → remain in one place w/in the connective tissue

    • ex: bone cells (osteocytes)

  • wandering → move through the tissue

    • ex: while blood cells (not red-they stay in vessels) can migrate into connective tissue to respond to infection or other immune issues

Locations of Connective Tissue - All Over The Body

• Bone → Provides strong structural support. Bone marrow (inside the bone) makes blood cells.

• Cartilage → Provides flexible support in joints 

• Tendons → Attach muscles to bones 

• Ligaments → Connect bones at joints 

• Blood → Transports oxygen and nutrients throughout the body 

• Adipose (fat) tissue → Stores fat for energy 

Connective Tissue Types

• Dense Connective (tendons and ligaments)

• Loose Connective (adipose and areolar → “loose connective tissue” + lots of collagen and elastic fibers + acts as “packing material” surrounding and supporting organs and other tissues)

• Bone

• Blood

• Cartilage