Exam 4 Study Guide - Section 2

Metabolic rate

Energy used over time

Four factors affecting metabolic rate

Age, sex, muscle mass, activity

Who has higher metabolic rate?

Person with more muscle

Why does body temperature matter?

Affects enzymes & cell function

Ectotherms rely on

External heat

Example of ectotherm

Lizard

Endotherms generate

Internal heat

Example of endotherm

Human

Radiation

Heat transfer by waves

Conduction

Heat transfer by contact

Convection

Heat transfer by moving air/water

Evaporation

Heat loss when liquid → vapor

Windy day heat loss is mainly by

Convection

Immune system protects from

Pathogens, toxins, abnormal cells

Innate immunity is

Nonspecific; no memory

Adaptive immunity is

Specific; memory

Pathogen

Disease‑causing agent

Three pathogen types

Bacteria, viruses, parasites

Two ways bacteria harm host

Toxins, tissue damage

Viruses replicate only inside

Host cells

Example parasite

Tapeworm

Innate immunity present at

Birth

Why nonspecific?

Same response to all pathogens

Three innate defenses

Skin, mucus, phagocytes

Skin is a ______ barrier.

Physical

Lysozyme found in

Tears, saliva

Lysozyme breaks down

Bacterial cell walls

Phagocytosis

Engulfing & digesting pathogens

Two phagocytes

Macrophages, neutrophils

Steps of phagocytosis

Recognition → engulf → digest

Mast cells release

Histamine

Four signs of inflammation

Redness, heat, swelling, pain

TLRs recognize

Pathogen molecules (PAMPs)

Adaptive immunity targets

Specific antigens

Two lymphocytes

B cells, T cells

B cells

Make antibodies

Plasma cells

Secrete antibodies