C3.1 Integration of body systems

System Integration

Coordination between and within systems

Define tissues

Group of cells

State the two cell types of alveoli in lungs

• AT1 (alveolar type 1)

• AT2

Define organs

Group of tissues working together to carry out specific functions of life

Draw trachea and label

List the 11 organ systems

• Ciculatory

• Digestive

• Endocrine

• Gas exchange

• Integumentary

• Lymphatic

• Muscular

• Nervous

• Reproductive

• Skeletal

• Urinary

Hormones and relation to integration

• Chemicals produced by endocrine glands

• Travel through blood stream

• Slower

• Only affects target cells (with right receptor protein)

Nervous signals and relation to integration

• Electrical impulses

• Transmitted by neurons to a specific location

• Affects muscles or glands only

• Rapid

• Very short

Functions of brain

• Receives information from one of our sensory organs

• Process and stores that information

• Brain processes information

• Brain may send signals to effector organs if a response is required

Parts of brain

(check labelled diagram)

Define CNS

Central Nervous System, consisting of spinal chord and brain

White matter tissue in spinal chord

Transmits signals from:

• Sensory receptors to brain

• Brain to other organs

Grey matter tissue in spinal chord

• Contains cell bodies and synapses

• Processing information

• Decision making

• Unconscious processes only

Types of sensory receptors

External and Internal

External sensory receptors examples

• Touch

• Heat

• Light

Internal sensory receptors examples

• Stretch receptors (think of expanding stomach)

• Chemo receptors

Motor cortex of brain

Has motor neurons originated, but axons go other places

Nerve + what it contains and transmits

• Bundle of nerve fibres surrounded of a sheath

• Contains both sensory and motor neurons

• Can only transmit signals one way

Reflex arc

Rapid, involuntary response to a specific stimulus

Steps of a reflex arc

1. Receptor picks up the stimulus (touch, heat, light, smell…)

2. Pain message is carried along sensory neuron

3. Gets to CNS and passes along to an interneuron

4. Message is transmitted along a motor neuron, goes away CNS

5. Goes into effector organs- initiates movement, etc

Interneuron

Goes between a sensory neuron and a motor neuron

Cerebellum

Back/bottom of brain, coordinates the timing of muscle contractions

List 3 things the cerebellum coordinates

• Balance

• Posture

• Things that require muscle memory

Melatonin

Hormone secreted by pineal gland that control circadian rhythm

Circadian rhythm

Pattern of sleep/wake cycles that organisms are adapted for

Effects of apinephrine secretion

• Hydrolysis of glycogen → glucose

• Decrease blood flow to gut and kidneys (vasoconstriction)

• Increase diametre of bronchi and bronchioles

• Increases heart rate

Explain how the hypothalamus works with osmoregulation

• If body solute concentration is too high, pituitary gland is prompted to release ADH

Explain how hypothalamus works with puberty

• Hypothalamus releases GnRH

  • Prompts pituitary to release LH and FSH

    • Initiate puberty

SA node

Sinoatrical node, at the top of the brain

Vagus nerve function

Causes SA node to slow down heart rate

Sympathetic nerve

Causes SA node to increase heart rate

State the two ways SA node is in feedback loops with

• Chemoreceptors

• Baroreceptors

Aorta

Distributes oxygenated blood to other parts of the body

Feedback loops

Series of inputs and responses

List what happens when an increase in (any) activity happens

• More muscle movement

• More ATP

• More cellular respiration

• More CO2

• Less pH- causes nerve signals to be passed to muscles that control our breathing

Peristalsis

Muscle contractions that move food through digestive tract

List voluntary parts of digestive system

• Initiation of swallowing

• Defecation (later in life)

List involuntary parts of digestive system

• Moving food through digestive tract

• Defecation (early in life)

Tropism

Growth responses to stimulus

Positive tropism

Growing towards stimulus (e.g: roots)

Negative tropism

Growing away from the stimulus

Lateral

On the other side

Phytohormone and its functions

Plant hormone:

• Growth

  • Promotes cell division/elongation

• Development

  • Promotes differentiation of plant tissues

• Response to stimuli

  • Control of tropisms

Auxin

Phytohormone that controls tropism

Auxin efflux carries

Transmembrane proteins that pump auxin into cells

Outlien how AEC help shoots frow away from the sunlight

• Can move around withing membrane

• If cells coordinate and move, the AEC to one side, high concentration of auxin can be established

• Shoot away from the sunlight

Outline promotion of cell growth by auxin

• Auxin promotes synthesis of proton pump

• Pumps protons into apoplast (outside cell wall)

  • Lowers the pH of cell wall (acidification)

  • Weakens the cell wall, and causes wall to elongate

• Elongation causes bending (positive phototropism)

Cytokinin

Another phytohormone; produced in roots and transported in shoots (opposite of auxin)

State a reason why seed disperal occurs

Parents don’t want to compete with offspring

Signals of ripening fruit

• Colour change

• Softening

• Scent production

• Sweetening

Ethylene

Phytochrome that works in a positive feedback look to ripen fruit

How does auxin exert its effect on plant cells

Binds to a receptor resulting in expression of genes

How auxin controls phototropism in plant shoots

1. Plant shoots bend towards light/sun

2. Auxin moves to shadier side from lighter

3. Moved by auxin efflux pumps

4. Auxin promotes cell wall acidification

5. Growth increases on shadier side

6. Binds to auxin receptors- they promote gene expression

Extension of stem in plants

• Cell division of shoot/stem

• Auxin stimulates stem extension

• Elongation of cells causes stem to grow