BIOL Exam 3

Chapter 25: Tissues & Organ Systems

Definitions:

  • Anatomy = structure of organisms

  • Physiology = function of body parts

  • Tissue = group of similar cells

  • Organ = multiple tissues performing a function

  • Organ system = organs working together

  • Organism = entire living being

Primary Tissues in Vertebrates:

  1. Epithelial – covers & protects, absorption

    • Membranous: skin, lining of organs

    • Glandular:

      • Exocrine = ducts (sweat, sebaceous glands)

      • Endocrine = ductless (thyroid, pituitary)

  2. Connective – supports & connects

    • Contains matrix with collagen & elastin fibers

    • Types: bone, cartilage, blood, adipose

  3. Muscle – contraction for movement

    • Skeletal: voluntary, striated

    • Smooth: involuntary, non-striated (digestive tract)

    • Cardiac: involuntary, striated, heart

  4. Nervous – neurons, transmit electrical signals

Homeostasis:

  • Negative feedback = response reverses change (ex: body temperature)

Integumentary System:

  • Functions: protection, sensation, temperature regulation

  • Layers: Epidermis, Dermis, Hypodermis

  • Exocrine glands: sweat & sebaceous

  • Skin cancer: most common = basal cell carcinoma, most deadly = melanoma

Chapter 26: Nervous System

Comparison:

  • Nervous = fast (electrical signals), short-lived

  • Endocrine = slow (hormones), long-lasting

Neuron Anatomy:

  • Dendrites = receive signals

  • Cell body (soma) = integrates signals

  • Axon = transmits signal to next neuron or muscle

  • Myelin sheath = speeds conduction (Nodes of Ranvier = saltatory jumps)

Neuron Types:

  • Sensory: carry signals to CNS

  • Interneurons: process info in CNS

  • Motor neurons: carry signals from CNS to effectors

CNS: Brain & spinal cord

  • Meninges & CSF protect

  • Gray = neuron bodies, White = myelinated axons

  • Brain: cerebrum, corpus callosum, cerebellum, hypothalamus, medulla, pons

  • Spinal cord: reflexes & communication

PNS:

  • Nerves outside CNS, sensory & motor

  • Somatic = voluntary; Autonomic = involuntary

    • Sympathetic = fight/flight

    • Parasympathetic = rest/digest

Reflex: involuntary response (knee jerk, withdrawal)

Chapter 30: Circulatory System

Functions: transport O₂, nutrients, waste, hormones, immune cells

Blood Components:

  • Plasma = water + solutes, 55% of blood

  • RBCs (erythrocytes) = carry O₂, hemoglobin, anucleate

  • WBCs (leukocytes) = immunity

    • Neutrophils & Monocytes = phagocytosis

    • Lymphocytes (T & B cells) = adaptive immunity

  • Platelets (thrombocytes) = clotting (prothrombin → thrombin → fibrin)

Pathologies: anemia, hemophilia, leukemia, infections

Blood Vessels:

  • Arteries = high pressure, pulse, 3 layers

  • Veins = valves, low pressure, skeletal muscle assists

  • Capillaries = diffusion, simple epithelium

Heart:

  • Chambers: 2 atria, 2 ventricles; valves: AV & semilunar

  • Coronary arteries supply heart

  • Pulmonary = lungs; Systemic = body

  • SA node → AV node → Purkinje fibers = heartbeat sequence

  • Blood pressure: systolic/diastolic, measured with cuff

  • ECG measures electrical activity

Chapter 31: Respiratory System

Air Pathway:
Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

Gas Exchange:

  • Occurs in alveoli

  • Diffusion: O₂ into blood, CO₂ out

  • Hemoglobin carries O₂

Mechanics of Breathing:

  • Diaphragm contracts → inhalation

  • Diaphragm relaxes → exhalation

  • Intercostal muscles assist

Control of Respiration:

  • Medulla monitors CO₂ levels

Respiratory Diseases: asthma, bronchitis, emphysema, tuberculosis, lung cancer

Chapter 35: Animal Reproduction & Development

Asexual vs Sexual:

  • Asexual: one parent, identical offspring; fast, no variation

  • Sexual: two parents, genetic variation; slower

Special Cases:

  • Hermaphrodite = both male & female organs

  • Parthenogenesis = females produce offspring without males