The Human Organism: An Overview Chapter 27 The Human Organism: An Overview

27.1 Structure fits function in the human body

Anatomy Structure of an organism and its parts

Physiology Function of the structures

Levels of Body Structure

1. Cells The human body is made up of ~75 trillion cells The human body is designed so that all cells can get what they need to survive and remove the waste that they create through metabolism. The human body is made up of ~75 trillion cells

Gas Exchange – an example of a chemical exchange with the surroundings and cells

Body exchanges with external environment Cells exchange with internal environment

27.2 A tissue is a group of cells with similar structure and function

4 types of tissues: A. epithelial B. connective C. nervous D. muscle

Epithelial Tissue Covers body surface and lines the internal organs

Connective Tissue Supports tissues, cushions, insulates, and connects organs

Nervous Tissue Forms the “communication system” of the body

Neuron Nerve cell Transmits signals

Muscle Tissue 3 types Skeletal Cardiac Smooth

Skeletal Muscle Attached to the bones of the skeleton Voluntary – you control it

Cardiac muscle Heart muscles Involuntary muscle – works without you controlling it

Smooth Muscle Involuntary Found in most other organs Ex. Digestive organs

There are 12 organ systems in the human body…

What ones can you name???

Please complete the organ systems matching on p.3 of your notes

Circulatory System B

Digestive System K

Endocrine System G

Integumentary System H

Muscular System J

Lymphatic System & Immune System

Nervous System A

C

D

Skeletal System F

Urinary System E

27.3 The body regulates its internal environment

Review: What is homeostasis???

Homeostasis Your body maintaining an ideal internal “steady state”

Two main body systems that work to maintain homeostasis…

What two body systems would regulate his escape?

Nervous System detects environmental stimuli & directs the body’s responses

Endocrine System Secretes hormones (into the blood) regulate other organ systems

ie. adrenaline triggers “fight or flight response” Hormones Signal molecules released into the bloodstream to trigger a response ie. adrenaline triggers “fight or flight response”

B. Integumentary System Body’s outer covering Barrier that helps maintain homeostasis

The skin has 4 major functions…

The skin has 4 major functions… a. protection (pathogens) b. temperature regulation c. excretion (waste products) d. secretion (useful products)

hair Sweat pore keratin epidermis nerve dermis oil gland sweat gland hair follicle sweat gland

Hair & Nails - Both made of a tough protein called keratin

Role in homeostasis Skeletal System Urinary System Nervous System Immune System Circulatory System

Ch 27b - The Skeletal & Muscular Systems

What is locomotion?

Locomotion The ability to move from one place to another

Why is locomotion helpful to an organism??

Improves chances of: a. finding a mate b. finding food c. finding shelter d. avoiding predators

Motile Organisms that are capable of locomotion

Sessile Organisms that are not capable of locomotion

Examples of sessile organisms… Coral Hydra Plants

The Skeleton functions in support and movement

Anatomy of the Skeleton…

Functions: 1. provides framework that holds the body up; maintains shape

2. protects soft organs Brain Spinal Cord Heart, Lungs a. skull protects: b. backbone protects: c. ribs protect: Brain Spinal Cord Heart, Lungs

Bones as Living Organs…

Bone matrix Made of the protein collagen (provides flexibility) and calcium & phosphate (makes bones strong)

Cartilage Flexible, elastic connective tissue which provides cushioning and flexibility at joints

A fetus has a skeleton that is made mostly of cartilage, which is very flexible for child birth.

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Adults have cartilage at ends of ribs, between vertebrae, ends of bones, nose, ear, and trachea

Marrow Yellow: found in central cavity of long bones, stored fat

Marrow Red: found in certain bones (humerus, hip, sternum), produces cells that become blood cells

Joints Places in the skeleton where bones are connected and make movement possible

Ligaments Tough elastic connective tissue that connect bone to bone at a movable joint

Joints: Hinge joints (elbow & knee) Ball and socket (hip & shoulder

Joints: Pivot joint (neck) Immovable joints (the bones of the skull)

Two examples of skeletal disorders are arthritis and osteoporosis…

Arthritis -itis means inflammation Inflammation of the joints

Osteoporosis Bones become thin, porous, more easily broken Prevention? calcium

27.5 Muscles move the skeleton by contracting

Tendons Tough, inelastic cords that attach muscles to bones

Antagonistic pairs Muscles usually operate in pairs One muscle extends (straightens), one muscle flexes (bends)

extension flexion

Example of antagonistic muscle pair

What is the structure of a muscle???

Recall… 3 types of muscles? Skeletal muscle Smooth muscle Cardiac muscle

Skeletal muscle Has the capacity to contract or shorten HOW?

Muscle fiber Long muscle cells with many nuclei (very unique cell)

Actin & Myosin The 2 types of protein that make up the muscle fiber

Actin & Myosin Responsible for the shortening and lengthening of skeletal muscles.

Let’s look at a Skeletal Muscle Animation