Biology: Types of Tissues

Tissues

• Epithelial tissue is responsible for secretion and absorption.
• Connective tissue includes tendons and holds organs in place.
• Muscle tissue is involved in contraction.
• Nervous tissue is responsible for communication within the body.

Feedback Loops

• An example of a negative feedback loop is thermoregulation.
• An example of a positive feedback loop is childbirth contractions.

Homeostasis

• Homeostasis refers to the body's ability to maintain a constant internal state despite external changes.

Blood Vessels

• Arteries carry blood away from the heart.
• Capillaries are involved in the exchange of materials by diffusion with nearby cells.
• Veins carry blood back to the heart and have one-way valves to prevent backflow.

Circulatory System

• The pulmonary circuit involves the right ventricle pumping blood to the lungs to get rid of carbon dioxide and pick up oxygen.
• The systemic circuit involves pumping blood throughout the whole body.
• The primary function of the circulatory system is to move oxygen from the lungs to the heart and pump nutrients to the rest of the body.

Other Systems

• The primary function of the respiratory system is to bring oxygen in and expel carbon dioxide.
• The primary function of the urinary system is to remove excess fluids and waste products.
• The primary function of the nervous system is to coordinate muscle functions.

Blood Composition

• Blood is composed of 55% plasma and 45% cells.

Blood Pressure

• Blood pressure is at its highest during the systolic phase.
• Blood pressure is at its lowest during the diastolic phase.

Blood Cells

• The primary function of red blood cells is to carry oxygen.
• The primary function of white blood cells is to act as immune cells.
• The primary function of blood platelets is to help prevent and stop bleeding.

Diaphragm

• When the diaphragm contracts, it moves downward.
• The diaphragm contracts during inhalation.