Unit 11 - Integration of Body Systems

Integration

Interacting parts of a biological system to perform together and maintaining a functioning organism or other biological system.

Coordination is…

________________ needed between component parts of a system to collectively perform an overall function.

Cells

The basic unit of life, or in other words, the smallest structural unit that is capable of using energy to sustain itself in a highly ordered state.

Tissue

Groups of cells that work together to perform a function. ___________ contain more than one type of cell. The cells must stick together and communicate with each other to coordinate function.

Organ

Group of tissues that work together to perform a function. Contains more than one type of tissue.

Organ Systems

Groups of organs that interact to perform a function.

Two mechanisms to integrate organ systems

1. Sending messages by the nervous system and endocrine system

2. Transport of materials and energy in the blood

Blood transports…

materials between organs in the body.

Assimilation

The uptake of nutrients into cells and using this material to make new biological molecules.

Monosaccharides

Absorbed into blood plasma which takes them to the liver and to other parts of the body.

Amino acids

Membrane protein pumps actively transport them and go to capillaries, where they dissolve into the blood plasma. The plasma transports them to the liver, where they are made into new proteins or held in reserve.

Short-chain fatty acids and glycerol

These are absorbed by simple diffusion into epithelial cells in the small intestine. They then diffuse into the blood stream.

Long-chain fatty acids

These combine with glycerol to form triglycerides, which then are coated with proteins in the epithelial cells. This new molecule/complex then enters the lymph, which transports them into the bloodstream.

Waste products: urea

______ is made by amino acids being broken down in the liver. It is toxic and filtered out by the kidneys.

CO2

A waste product from cell respiration and is carried by the blood and taken out of the body in the lungs.

Central nervous system

composed of the brain and spinal cord and contains relay neurons.

Peripheral nervous system

Composed of cranial, spinal, and peripheral nerves and contains sensory and motor neurons.

Brain controls bodily functions by:

• sensory receptor signals

• integrating & correlating incoming info in association centers

• sending impulses to the effector organs (muscle/glands)

• storing info and building up an accessory memory bank

• starting impulses

Conscious processes

When the brain intentionally sends nerve impulses through the spinal cord to the rest of the body.

Unconscious processes

When the brain does not intentionally send these signals, but instead, the body initiates the sending of the signals through the spinal cord.

Examples of Unconscious processes

• reflexes

• sweating of the lower half

• defecation

• urination

Cerebral hemispheres

The bulk of the human brain, formed during development and outgrowth of the forebrain; consists of densely packed neurons and myelinated nerve fibers.

Sensory neurons

Neurons that sense things in the environment.

Nerve

A bundle of many axons of neurons. They can contain either or both sensory and motor neurons. _______ fibers can be myelinated or unmyelinated.

Cerebellum

It is part of the hindbrain (the back of the brain); concerned with muscle tone, posture, and movement. It receives input from receptors and adjusts commands to motor neurons to move the body to maintain balance.

circadian rhythm

physical, mental, and behavior changes that occur in the 24 hour cycle.

Things controlled by circadian rhythm

• physical activity

• sleep

• body temperature

• secretion of hormones

melatonin

A hormone made by the pineal gland

Effects of melatonin

• drop in body temperature

• drowsiness

• sleep

How melatonin secretion works

Light sensors in our eyes detect light and send signals to the CNS to inhibit the production of ___________ in the pineal gland. When light is no longer present, ___________ is once again produced and travels to various places in our body through our blood (hormone).

Epinephrine

A hormone secreted by the adrenal glands when the body is under stress and is about to prepare for vigorous activity (fight or flight response).

Goal of epinephrine

To increase glucose and and oxygen supply to the skeletal muscles so that the flight or flight response can occur.

Effects of epinephrine

• hydrolysis of glycogen to glucose in the liver

  • The glucose goes to the blood which inc the rate of resp in muscle tissue and facilitates intense muscle contractions

• helps increase the diameter or the bronchi and bronchioles which helps deliver O2 to blood

• ventilation rate and tidal volume increase

• SA node increases heart rate (helps deliver glucose and O2 through blood to the skeletal muscles

• vasodilation in liver and muscles

• vasoconstriction in gut and kidneys

Hypothalamus

Structure at the base of the brain; control center for the autonomic nervous system and source of hormones for the pituitary gland

Role of the hypothalamus

• Connects nervous and endocrine systems

• receives signals from other parts of the brain and sensors for things like light, temp, blood glucose, etc, and feelings

• releases hormones that signal or suppress the pituitary gland and other glands and organs

Hypothalamus to pituitary communication

The hypothalamus receives nerve signals (input based on environmental stimuli) and then sends hormonal signals (hormones or sometimes other nerve impulses) to the pituitary gland. The pituitary gland then releases hormones that affect various parts of the body.

Medulla

The structure at the base of the brain, where the brain stem connects the brain to the spinal cord. it also coordinates responses and sends nerve impulses to the heart using baroreceptors and chemoreceptors.

Respiratory center

A region of the medulla (medulla oblongata) that is concerned with the involuntary control of breathing.

Low blood pressure and high [CO2]

The medulla increases the rate of SA node firing through the sympathetic nervous system to increase heart rate (allows more blood to pump, increasing blood pressure, and also allows the blood to flow to the lungs so CO2 can be removed).

High blood pressure and low [CO2]

The cardiovascular control center reduces SA node firing by activating the parasympathetic nervous system.

Inspiratory center

Sends impulses to increase rate and depth of breathing.

Expiratory center

Sends impulses to inhibit the inspiratory center and stimulate expiration.

What causes rhythmic breathing?

The alternating impulses from the inspiratory center and the expiratory center.

Autonomic nervous system

The involuntary nervous system.

Enteric nervous system

A network of sensory, motor, and interneurons imbedded in the wall of the gastrointestinal system.

Peristalsis

Muscle contractions that move food through the digestive tact.

CNS control of digestion

Swallowing food and removal of feces.

ENS control of digestion

Peristalsis and pooping in earlier stages of life.

Tropism

Growth response of plants where the direction of growth is determined by the direction of the stimulus.

Positive tropism

Plant grows toward the stimulus.

Negative tropism

Plant grows away from the stimulus.

Phototropism

The response of plants to light (the plant grows in the direction of the light).

Phytohormones

Plant hormones that regulate the growth, development, reproductive processes, longevity, and death of plants. They are responsible for the adaptation of plants to environmental stimuli.

Phytohormones occur….

In low concentrations (they can diffuse from cell to cell or be carried in the phloem/xylem).

Auxin

A phytohormone that is responsible for the growth of stems and roots, dominance of terminal buds, fruit growth, and inhibition of leaf fall.

Gibberellins

Phytohormones that stimulate cell division and cell elongation, break dormancy of seeds, and switch on genes for seed germination.

Abscisic acid

A stress hormone that triggers stomatal closure when cells do not have enough water, induction of buds, and seed dormancy.

Ethylene

A phytohormone (and gas) that is responsible for fruit ripening.

Two main roles for auxin

1. promotes the growth of shoot apex, where it promotes elongation of cells

2. Inhibits growth and development of lateral buds that occur immediately below the terminal growth point.

Auxin efflux carriers

Transmembrane proteins that carry auxin and transport them into the cell. They can freely move between different cells and help to contribute to auxin concentration gradient.

How auxin promotes cell growth

Auxin stimulates proton pumps which pump H+ into the cells, which lowers the pH and makes the cell wall acidic. The low pH causes breakage of cross-links in cellulose and hydrolytic enzymes come and attack exposed areas. The wall resistance goes down, and the cell turgor causes the cell to elongate.

Cytokinin

A phytohormone that influences plant growth, development, and physiology, including cell division.