HNF 150 Lecture Notes - Lecture 2: Digestion, British Association For Immediate Care, Inulin
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BODY BASICS AND DIGESTION
Cells are the smallest unit of life. The human body is composed of trillions of
cells. Each cell functions as a self-contained living entity. Cells have various
functions and die at varying rates.
The body’s cells need (3):
2. Organs and Tissues
• Cells are organized into tissues.
• Tissues are organized into organ systems.
• Organ systems work together as part of body systems.
3. BODY SYSTEMS
A. Circulatory and Lymphatic System
2 Types of
BODY FLUIDS: 1) ________________ and 2) ______________
Arteries = carry blood containing fresh oxygen from heart to tissues
Veins = carry blood with carbon dioxide from tissues to heart
Red Blood Cell = cell that transport oxygen in the cell
Lymphatic system = has own separate vessels
Extracellular fluid surrounding cells = derived from capillaries, some goes back
into the blood stream through the capillaries and some becomes lymph fluid and
flows thorugh the lymph vessals
Adequate circulation requires (3):
B. Hormonal System =
1. Insulin is secreted by ______________ when blood glucose is
_______________. Insulin tells the cells to remove glucose from blood and
2. Glucagon is secreted by _____________ when blood glucose is
______________. Glucagon tells the liver to release stored glucose into the
How can nutrition can affect hormonal balance?
-- Fasting, feeding, and exercise all alter hormonal balances.
C. Nervous System = also part of body’s communication system
Consists of: Brain, spinal cord and nerve cells
Nervous system has a role in nutrition, for example hunger. Digestive system
sends messages to the hypothalamus through nerves and hormones to signal the
need for nutrients. Sensation of hunger and appetite are perceived by the
brain’s cortex (the thinking part of the brain), which can override signals – either
eat when we are not hungry or not eat when we are.
Fight or Flight Response (Combination of Hormonal and Nervous System) =
Another name for the fight or flight response =
When we detect danger…
1. Nerves release neurotransmitters
2. Glands release the hormones: ____________ and ___________
3. Every organ responds and Metabolism speeds up
4. Liver releases glucose from stores
5. Fat cells release fat
→ Heart races, pupils of eyes widen, muscles tense, digestion shuts
down, breathing quickens, blood pressure rises.
D. Excretory System
Cells generate wastes that must be eliminated by the body through the:
What do kidneys need (4 things)?
E. Storage System
What are the 3 important organs of the storage system and what do they store?
F. Immune System
What is immunology?
• How the body distinguishes self from non-self.
• What it does when a “non-self” component is recognized.
• How the response is regulated and system returned to “normal”.
The Immune System
A complex network of tissues, cells and molecules that
interacts and uses various mechanisms to achieve resistance or immunity to a
variety of threats to the host.