Introduction to Human Anatomy and Physiology

Requirements of Organisms: Life depends on the availability of the following: a.Water (required for metabolic reactions, for transport of substances, for temperature regulation) b.Food (nutrients needed to supply energy and raw materials for building new living matter) c.Oxygen (used in releasing energy from nutrients) d.Heat (a byproduct of metabolism; its presence governs the rate at which reactions occur)

Homeostasis: Maintenance of a stable internal environment is called homeostasis. Homeostasis is regulated through control systems which have receptors, a set point and effectors in common. Examples include: a. Homeostatic mechanisms regulate body temperature in a manner similar to the functioning of a home heating thermostat. b. Another homeostatic mechanism employs pressure-sensitive receptors to regulate blood pressure.

Skeletal/Muscular Systems Function: Enable movement, provide support and protection for tissues & organs

Skeletal/Muscular Systems Major Organs Involved: Bones! and Muscles!! Bones are attached to other bones by ligaments Muscles are attached to bones by tendons

Skeletal/Muscular Systems More stuff: Actin & myosin are 2 protein fibers in muscle cells that allow them to contract and relax RJq4w

Skeletal/Muscular Systems More stuff: There are three types of muscle tissue: 1.Skeletal muscle tissue – found in muscles that attach to bones (bicep, tricep) 2.Smooth muscle tissue – found in muscles of organs (stomach, intestines) 3.Cardiac muscle tissue – specific type of muscle tissue of the heart

Integumentary System Functions: Retain fluids Protection – 1 st line of defense Temperature control – sweat glands Eliminate wastes – sweat and oil glands

Integumentary System Major Organs: Skin Sweat and oil glands Hair Nails

Integumentary System More Stuff: Layers of the skin: Epidermis – outer most layer Dermis – thick middle layer Hypodermis/Subcutaneous Layer – inner most layer

Nervous System Functions: relay chemical-electrical impulses to all the muscles of the body

Nervous System Two Main Parts: 1.Central Nervous System – brain & spinal cord 2.Peripheral Nervous System – nerves of the body

Nervous System Nerve Cells: called neurons, the transmitting cells of the body

Endocrine System Functions: Regulates water & electrolyte balance Maintains metabolism Controls response to stimuli Regulates growth, development, & reproduction Produces hormones

Endocrine System Major Organs: pituitary, thyroid, adrenal, pineal, and parathyroid glands, pancreas, males & female reproductive organs

Endocrine System More Stuff: The chemical messengers secreted by one part of the body, travel in the blood, and target another part of the body are called hormones. Two types: steroid and non-steroid

Digestive System Function: mechanical and chemical breakdown of food so nutrients can be absorbed by the body’s cells.

Digestive System Major Organs:

Digestive System More Stuff: Food is mostly absorbed in the small intestines Water is mostly absorbed in the large intestines

Excretory/Urinary System Function: filters the blood and removes wastes (salt, acids, etc.)

Excretory/Urinary System Each Kidney is made of functional units called nephrons.

Respiratory System Function: exchange oxygen and carbon dioxide

Respiratory System When oxygen is inhaled it goes down the wind pipe, also called the trachea. The trachea splits into two tubes called the bronchial tubes, which lead into the lungs. The bronchial tubes end in air sacs (within the lungs) called alveoli. Every cell in our body needs oxygen to go into the mitochondria to perform cellular respiration.

Respiratory System

Circulatory System Function: carries nutrients, oxygen, hormones, and wastes through the body and distributes heat to maintain homeostasis.

Circulatory System Major Organs: Arteries carry oxygen rich blood away from the heart Veins carry blood with carbon dioxide back to the heart Capillaries are the smallest blood vessels & is where gas, nutrient, and heat exchange occurs

Circulatory System Types of Cells in Blood: 1.Red Blood Cells (RBC’s) – carry oxygen and carbon dioxide 2.White Blood Cells (WBC’s) – fight infections, respond to allergies 3.Platelets – cell fragments that stick together to form clots

Immune/Lymphatic System Function: helps fight infections throughout the body

Immune/Lymphatic System A vector is something that carries a pathogenic disease. Insects Body fluids Viruses Plasmids (ring of bacterial DNA)

Human Eye

Human Eye - Anatomy A. The Outer Layer – fibrous outer layer 1. Cornea – transparent “window” at the front of the eye; focuses entering light onto the retina (retina is a part of the inner layer). 2. Sclera – “whites” of the eye; protects eye and is attachment for extrinsic muscles 3. Optic nerve and blood vessels pierce the sclera at the back of the eye; carries sensory impulses to the brain

B. Middle Tunic – vascular layer 1. Choroid Coat – joined to sclera, contains many blood vessels that nourishes other tissues of the eye; produces pigments that absorb excess light to keep the inside of the eye dark. 2. Ciliary Body – forms a ring around the front of the eye and is made of small muscles and suspensory ligaments that hold the lens in position and change its shape (focus).

3. Lens – focuses light onto retina 4. Iris - thin, smooth muscle anterior to the ciliary body that adjusts the amount of light entering the pupil, a hole in the iris’s center 5. Aqueous Humor – watery fluid that fills space between cornea and lens; nourishes these parts and maintains shape of the eye

C. Inner Tunic – nervous inner layer 1. Retina – contains visual receptor cells a) Rods – very sensitive to light, so can provide vision in dim light; Produce colorless vision; give less precise images (outlines of objects) b) Cones – provide sharper images of color 3 types of cones: 1 is sensitive to red light, 1 is sensitive to green, & the other is sensitive to blue

2. Fovea Centralis – depression in the center of the retina where there are only cones; region where retina produces sharpest vision 3. Optic Disc – area where nerve fibers of the retina converge and join the optic nerve; this area lacks rods/cones, and is known as your “blind spot” 4. Posterior Cavity – contains lens, ciliary body, and retina; filled with vitreous humor 5. Vitreous Body – collagenous fibers support internal parts of the eye

Human Eye