Study Guide - Units 5-8 Overview

UNIT 5: Tissues and Integumentary System

Four Categories of Tissues:

• Epithelial: Covers body surfaces and lines cavities.

• Connective: Supports, protects, and binds other tissues.

• Muscle: Contracts to produce movement.

• Nervous: Receives stimuli and transmits impulses.

Epithelial Tissue:

• Function: Protection, absorption, secretion, and filtration.

• Types:

  • Simple squamous: diffusion/filtration (lungs, vessels)

  • Simple cuboidal: secretion/absorption (kidneys)

  • Simple columnar: absorption/secretion (digestive tract)

  • Stratified squamous: protection (skin, mouth)

  • Pseudostratified columnar: secretion/movement (respiratory)

  • Transitional: stretch (bladder)

• Homeostasis: Maintains barriers and controls permeability.

Connective Tissue:

• Functions: Support, protection, insulation, storage, transport.

• Types:

  • Loose: areolar, adipose, reticular

  • Dense: dense regular, dense irregular, elastic

  • Supportive: hyaline cartilage, fibrocartilage, elastic cartilage, compact bone

  • Fluid: blood, lymph

Examples and Locations:

• Areolar: under epithelia (cushions organs)

• Reticular: lymph nodes, spleen (supports soft tissue)

• Adipose: under skin, around organs (stores fat)

• Dense regular: tendons, ligaments

• Hyaline cartilage: nose, trachea, ends of long bones

• Compact bone: skeleton

• Blood: within blood vessels

Muscle Tissue:

• Skeletal: voluntary movement; attached to bones

• Cardiac: involuntary, pumps blood; heart wall

• Smooth: involuntary, moves substances; walls of hollow organs

Nervous Tissue:

• Neurons: transmit impulses (brain, spinal cord)

• Neuroglia: support and protect neurons

Embryonic Origins:

• Ectoderm: skin, nervous system

• Mesoderm: muscles, bones, blood, kidneys

• Endoderm: lining of GI and respiratory tracts

Skin Layers and Cells:

• Epidermis: keratinocytes, melanocytes, Langerhans, Merkel

• Dermis: fibroblasts, collagen, elastin

• Hypodermis: adipose tissue

Functions of Skin:

1. Protection

2. Sensation

3. Thermoregulation

4. Metabolic functions (vitamin D)

5. Blood reservoir

6. Excretion

Thick vs Thin Skin:

• Thick: palms/soles, 5 layers, no hair

• Thin: covers rest of body, 4 layers, has hair

Skin Receptors:

• Meissner's corpuscles: light touch

• Pacinian corpuscles: pressure/vibration

• Merkel discs: steady pressure

• Ruffini endings: stretch

• Free nerve endings: pain, temperature

• Krause end bulbs: cold

Skin Appendages:

• Hair: protection, sensory

• Arrector pili: goosebumps, insulation

• Nails: protect fingertips

• Sudoriferous glands:

  • Eccrine: temperature control

  • Apocrine: emotional sweating

• Sebaceous glands:

  • Secrete sebum

  • Lubricate skin/hair, antibacterial

Skin Cancer:

• Basal cell carcinoma: least dangerous, basal layer

• Squamous cell carcinoma: may metastasize, stratum spinosum

• Melanoma: most dangerous, melanocytes

Wound Healing:

• Regeneration: replaces with same tissue

• Fibrosis: replaces with scar tissue

: NerUNIT 6vous System

Five Functions:

1. Sensory input

2. Integration

3. Motor output

4. Homeostasis

5. Mental activity

Nervous System Divisions:

• CNS: brain and spinal cord

• PNS: cranial and spinal nerves

Neuroglia Cells:

• Astrocytes: support neurons, BBB (Blood Brain Barrier)

• Oligodendrocytes: myelinate CNS

• Microglia: phagocytes

• Ependymal: CSF (Cerebrospinal Fluid) circulation

• Schwann cells: myelinate PNS

• Satellite cells: support PNS neurons

Neuron Types:

• Sensory (afferent)

• Motor (efferent)

• Interneurons – most common

Functional Divisions:

• Somatic: voluntary control

• Autonomic: involuntary (sympathetic/parasympathetic)

Action Potential Stages:

1. Resting potential

2. Depolarization

3. Repolarization

4. Hyperpolarization

5. Refractory period

Brain Regions:

• Brainstem:

  • Medulla oblongata: HR (Heart Rate), breathing

  • Pons: breathing, communication

• Diencephalon: thalamus, hypothalamus (homeostasis)

• Cerebrum:

  • Frontal: motor, speech

  • Parietal: sensory

  • Temporal: hearing, memory

  • Occipital: vision

• Cerebellum: coordination, balance

• Pineal gland: melatonin

Cranial Nerves:

• Olfactory (smell)

• Optic (vision)

• Auditory (hearing)

• Glossopharyngeal (taste/swallow)

• Facial (facial expression)

• Trigeminal (face sensation)

• Vagus (parasympathetic)

Definitions:

• Sensation: awareness of stimuli

• Perception: interpretation

• Sensory receptor: detects stimuli

• Integration: process of interpreting input

• Response: reaction to stimuli

• Myelin sheath: insulates axon

• Summation: combined stimuli

• Synapse: neuron communication site

• Neurotransmitter: chemical messenger

Sensory Pathways:

• Smell: olfactory bulb → cortex

• Taste: facial, glossopharyngeal, vagus nerves → brainstem

• Sight: retina → optic nerve → occipital lobe

• Hearing: cochlea → auditory nerve → temporal lobe

General vs Special Senses:

• General: touch, pain, temp

• Special: vision, hearing, taste, smell, balance

Structural Receptors:

• Free nerve endings, encapsulated, specialized cells

Rods and Cones:

• Rods: low light, no color

• Cones: bright light, color

Static vs Dynamic Equilibrium:

• Static: head position (vestibule)

• Dynamic: rotation (semicircular canals)

UNIT 7: Skeletal System

Six Functions:

1. Support

2. Protection

3. Movement

4. Mineral storage

5. Blood cell formation

6. Energy storage

Cartilage Types:

• Hyaline, fibrocartilage, elastic

Key Terms:

• Osteoid: unmineralized bone matrix

• Matrix: extracellular material

• Diaphysis: shaft

• Epiphysis: ends

• Metaphysis: between dia- and epiphysis

• Articular cartilage: joint cover

• Medullary cavity: marrow cavity

• Periosteum: outer layer

• Endosteum: inner layer

Bone Cells:

• Osteogenic: stem cells

• Osteoblasts: build bone

• Osteocytes: maintain bone

• Osteoclasts: break down bone

• Chondroblasts: form cartilage

Bone Shapes:

• Long, short, flat, irregular, sesamoid, sutural

Fractures:

• Greenstick, transverse, spiral, comminuted, oblique, compression, impacted, open

Endochondral Ossification:

• Cartilage model → bone collar → primary ossification center → medullary cavity → secondary centers

Bone Repair:

1. Hematoma

2. Fibrocartilaginous callus

3. Bony callus

4. Remodeling

Bone Markings:

• Projections, depressions, openings

• Examples: condyle, meatus, tubercle, process, tuberosity, spine, head, foramen, fossa, crest

Spongy vs Compact Bone:

• Spongy: porous, trabeculae

• Compact: dense, osteons

Growth Types:

• Elongation: length

• Appositional: width

Joints:

• Fibrous: no cavity (sutures, syndesmoses, gomphoses)

• Cartilaginous: little/no movement (synchondroses, symphyses)

• Synovial: cavity, freely movable

Synovial Joint Anatomy:

• Articular cartilage, synovial fluid, meniscus, bursa, synovial membrane, joint cavity

UNIT 8: Muscular System

Eight Functions:

1. Movement

2. Posture

3. Support

4. Guard entrances/exits

5. Heat production

6. Nutrient reserves

7. Blood flow

8. Stabilization

Key Terms:

• Fascia: CT covering

• Sarcolemma: muscle cell membrane

• T-tubules: conduct impulses

• Muscle fatigue: loss of power

• Relaxation: calcium reuptake

• Tension: force

• Tetany: sustained contraction

• Isotonic: change in length

• Isometric: no change in length

• Muscle tone: continuous partial contraction

Muscle Types:

• Skeletal, cardiac, smooth

Sarcomere:

• Contractile unit

• Actin = thin, Myosin = thick

Neuromuscular Junction (NMJ):

• Motor neuron, synaptic cleft, ACh, muscle fiber

Sliding Filament Model:

• Myosin pulls actin → shortening of sarcomere

Contraction Steps:

1. Nerve impulse

2. ACh release

3. Calcium release

4. Cross-bridge formation

5. Power stroke

6. Detachment

ATP Sources:

• Creatine phosphate

• Anaerobic glycolysis

• Aerobic respiration

Muscle Growth:

• Hypertrophy: increase in size

• Atrophy: decrease in size

Myoglobin vs Hemoglobin:

• Myoglobin: stores $O_2$ in muscle

• Hemoglobin: carries $O_2$ in blood