Cellular Respiration and Tissue Types Overview

Glycolysis

Anaerobic process in the cytoplasm where glucose is broken into 2 pyruvate, producing 2 NADH and 2 net ATP.

Citric Acid Cycle

Aerobic process in the mitochondrial matrix; uses Acetyl-CoA to produce CO₂, NADH, FADH₂, and 2 ATP.

Electron Transport Chain

Aerobic process in the inner mitochondrial membrane; uses oxygen as the final electron acceptor to produce ~32 ATP.

ATP from one glucose

~36-38 ATP total from glycolysis, Krebs cycle, and ETC.

Cellular respiration location

Cytoplasm (glycolysis), mitochondria (Krebs and ETC).

Oxygen use in respiration

Glycolysis is anaerobic; Krebs and ETC require oxygen.

Tissue

A group of similar cells performing a common function.

Histology

Study of tissues.

Matrix

Non-living substance around cells; varies by tissue.

Tissue connections

Tight junctions, desmosomes, gap junctions.

4 tissue classes

Epithelial, Connective, Muscle, Nervous.

Epithelial tissue

Covers surfaces, lines cavities, forms glands; little matrix, avascular, regenerates well.

Connective tissue

Supports, connects, protects; made mostly of matrix.

Muscle tissue

Contracts to cause movement; includes skeletal, cardiac, smooth.

Nervous tissue

Sends signals; made of neurons and glia; low regeneration.

Simple squamous epithelium

One flat layer; in alveoli.

Simple columnar epithelium

One column layer; lines stomach; may have goblet cells, cilia, or microvilli.

Stratified columnar epithelium

Multiple layers, top cells columnar; male urethra.

Pseudostratified columnar epithelium

One layer that appears multi-layered; trachea lining.

Stratified squamous epithelium

Many flat layers; skin and cheeks.

Simple cuboidal epithelium

One cube-shaped layer; kidney tubules.

Stratified cuboidal epithelium

Multiple layers of cube cells; sweat gland ducts.

Transitional epithelium

Stretches; bladder lining.

Endocrine glands

Secrete into blood or lymph.

Exocrine glands

Secrete into ducts.

Merocrine glands

Secrete via vesicles; salivary glands.

Apocrine glands

Tip of cell pinches off; mammary glands.

Holocrine glands

Entire cell ruptures; sebaceous glands.

Loose connective tissue

Gel matrix with hyaluronic acid; under epithelia.

Dense connective tissue

Regular or irregular; many fibers.

Adipose tissue

Stores fat; made of adipocytes.

Reticular tissue

Network of fibers in soft organs.

Cartilage

Matrix + chondrocytes; types: hyaline, fibrocartilage, elastic.

Bone tissue

Solid matrix; osteocytes; organic (collagen), inorganic (calcium phosphate).

Blood

Fluid matrix (plasma); has RBCs, WBCs, and platelets.

Skin

Largest organ; composed of epidermis, dermis, hypodermis.

Epidermis

Stratified squamous epithelium; outer layer.

Dermis

Middle layer; connective tissue, blood vessels, nerves.

Hypodermis

Subcutaneous fat layer; areolar and adipose tissue.

Stratum corneum

Dead, keratinized cells; outermost.

Stratum lucidum

Only in thick skin (palms, soles).

Stratum granulosum

Granule layer; makes keratin.

Stratum spinosum

Thick layer; has keratinocytes.

Stratum basale

Deepest layer; mitosis site.

Keratinocytes

Produce keratin; most common epidermal cell.

Melanocytes

Produce melanin; protect from UV.

Dendritic cells

Immune function in skin.

Tactile cells

Detect touch.

Hair structure

Shaft, root, follicle, bulb, papilla.

Nail structure

Body, root, matrix, lunula, cuticle.

Skin functions

Protection, sensory input, vitamin D, temp regulation, waste excretion.

Burn types

1st degree (epidermis), 2nd degree (epidermis + dermis), 3rd degree (all layers).

Rule of Nines

Estimates burn coverage percentage.

Skin cancers

Basal cell, squamous cell, melanoma.

Tissue healing

Inflammation, clotting, regeneration, scarring.

Skeletal system functions

Support, movement, protection, mineral storage, blood cell production.

Calcium in bone

Stores ~99% of body's calcium.

Hematopoiesis

Blood cell formation in red marrow.

Compact bone

Dense outer layer; contains osteons.

Spongy bone

Porous interior; has trabeculae and marrow.

Trabeculae

Struts in spongy bone aligned with stress.

Long bones

Longer than wide; femur.

Short bones

Cube-like; carpals.

Flat bones

Thin, flat; sternum.

Irregular bones

Complex shapes; vertebrae.

Sesamoid bones

Embedded in tendons; patella.

Diaphysis

Shaft of long bone.

Epiphysis

Ends of long bone.

Metaphysis

Region between diaphysis and epiphysis.

Medullary cavity

Central cavity; holds marrow.

Periosteum

Outer membrane; bone repair and growth.

Endosteum

Lines medullary cavity.

Red marrow

Produces RBCs, WBCs, and platelets.

Yellow marrow

Stores fat; can convert to red.

Osteogenic cells

Stem cells that become osteoblasts.

Osteoblasts

Build bone matrix.

Osteocytes

Mature bone cells maintaining matrix.

Osteoclasts

Break down bone for remodeling.

Organic bone components

Collagen fibers and osteoid.

Inorganic bone components

Hydroxyapatite (calcium phosphate); 65% of bone mass.

Sacrificial bonds

Help bone resist stress/fracture.

Calcium regulation

PTH increases blood calcium; calcitonin lowers it.