Human Biology Unit 3 WACE ATAR

Oxytocin and ADH

Released by the Hypothalamus

Gonadotropins (FSH, LH), Growth Hormone, THS, ACTH, Prolactin

Controlled by Anterior Pituitary

Melatonin

Produced by the Pineal Gland

Thyroxine

Stimulates metabolism in almost all body tissue

Thymosins

Associated with the Thymus Gland

Parathyroid Hormone

Produced by Parathyroid Glands

Adrenaline, Noradrenaline

Released by the Adrenal Medulla

Corticosteroids, Aldosterone

Secreted by the Adrenal Cortex

Insulin and Glucagon

Hormones from the Pancreas

Passive Artificial Immunity

Antibodies injected into the bloodstream

Active Natural Immunity

Ability to manufacture antibodies after disease exposure

Active Artificial Immunity

Ability to produce antibodies from vaccination

Immunisation

Programming immune system for rapid response to pathogens

Vaccination

Introduction of pathogen antigens to acquire antibody production

Bactericidal

Kill bacteria by altering cell structure or disrupting protein synthesis

Bacteriostatic

Inhibit bacterial reproduction by disrupting protein synthesis

Broad Spectrum Antibiotics

Effective against a wide range of bacteria types

Narrow Range Antibiotics

Targeted to kill specific microbes

Multiple Drug Resistance

Insensitivity to three or more antimicrobials by superbugs

Total Drug Resistance

Resistance of some strains of bacteria to all antibiotics

Antibiotics

Compounds that block the growth and reproduction of bacteria

Bacteria

Single-celled organisms that lack a nucleus; prokaryotes

Virus

Tiny, nonliving particle that invades and reproduces inside a living cell

Bacteriophage

Virus that multiplies in a bacterial cell

Exocrine Gland

Gland that releases a secretion external to or at the surface of an organ by means of a canal or duct

Endocrine Gland

Glands that release hormones into the bloodstream via the extracellular fluid

Hormones

Alter cell function by changing types, activity, quantity of proteins produced

Paracrines

Local hormones that affect cells other than those that secrete them

Protein and Amine Hormones

Group of hormones that attach to receptor proteins in the membrane of the target cell, activating a secondary messenger

Steroid Hormones

Lipid soluble and diffuse directly into cell to form a hormone-receptor complex

Hormone Function

Regulates enzyme production by controlling transcription/translation rate

Enzyme Amplification

Series of reactions where each step produces more product molecules

Hormone Clearance

Liver and kidney degrade hormones after their function is served

Negative Feedback

Response opposes stimulus caused by hormone secretion

Releasing Factors

Stimulate hormone release

Inhibiting Factor

Slows down hormone secretion

Hypothalamus

Directs maintenance activities (eating, drinking, body temperature), governs the endocrine system, linked to emotion and reward

Pituitary Gland

Located under hypothalamus, connected by infundibulum

Anterior Lobe of Pituitary Gland

Release hormones like Gonadotropins, Growth hormone, TSH, ACTH; controlled by releasing and inhibiting factors

Posterior Lobe of Pituitary Gland

Stores and releases hormones from hypothalamus like Oxytocin and ADH; produced by neurosecretory cells

Pineal Gland

Secretes melatonin, affected by light/darkness, decreases after puberty

Thyroid Gland

Regulates metabolism, body heat, bone growth; secretes thyroxine in response to TSH

Thymus Gland

Located in mediastinal cavity, secretes thymosin, influences T-lymphocyte maturation

Parathyroid Glands

Regulate calcium and phosphate balance in blood, bones, and tissues

Adrenal Medulla Gland

Produces epinephrine and norepinephrine, prepares body for threatening situations

Adrenal Cortex Gland

Produces corticosteroids, cortisol for metabolism and stress response, repair tissues

Pancreas Gland - Exocrine

Located under stomach, exocrine function secretes digestive enzymes into small intestine

Pancreas Gland - Endocrine

Located under stomach, islets of langerhans secrete insulin and glucagon for blood glucose regulation

Gonad Glands

Produce male sex hormones (androgens) in testes and female sex hormones (oestrogens and progesterone) in ovaries

Central Nervous System

Brain and spinal cord, the 'control centre' of the body

Peripheral Nervous System

Connects the central nervous system to the rest of the body through sensory and motor neurons

Ganglia

Group of nerve cell bodies located in the peripheral nervous system

Sensory Fibres

Carry impulses from receptors into the central nervous system

Motor Fibres

Carry impulses away from the central nervous system

Ventral Root

Contains axons of motor neurons

Dorsal Root

The sensory branch of each spinal nerve

Dorsal Root Ganglion

Nodule on a dorsal root containing cell bodies of afferent spinal nerve neurons

Afferent (Sensory) Neurons

Fibres that carry impulses into the central nervous system by sensory nerve cells from receptors

Somatic Sensory Neurons

Monitor external environment

Visceral Sensory Neurons

Monitor internal environment

Efferent (Sensory) Neurons

Carries nerve impulses away from the central nervous system to effectors such as muscles or glands

Autonomic Nervous System

Responsible for controlling the involuntary activity of visceral muscles, internal organs, and glands. Regulated by nerve cells in the medulla oblongata, hypothalamus, and cerebral cortex.

Autonomic Division

Consists of two nerve fibers from the CNS to the effector with a synapse in the ganglion

Somatic Division

Uses acetylcholine as a neurotransmitter

Fight or Flight

A reaction caused by adrenaline that prepares one to either fight the stressor or take flight and escape

Homeostasis

Balance between sympathetic and parasympathetic systems

Hormonal

Travel throughout the body via the blood, affecting multiple organs

Nervous

Nerve impulses along nerve fibers to specific body parts, influencing one effector

Noradrenaline, ADH, dopamine

Function as hormones and neurotransmitters

Feedback loop

Stimulus, receptor, message, modulator, effector, response, feedback

Protein and Amine hormones

Attach to cell membrane, activate secondary messenger, water soluble, activate enzymes, change reaction rate, form hormone-receptor complex

Receptors

- Specific to particular hormones

- Limited in number, saturation prevents reaction increase

Dendrite

Bushy extensions of a neuron that receive messages and conduct impulses towards cell body

Cell body

Largest part of neuron; contains nucleus and cytoplasm

Axon

Carries nerve impulses away from the cell body

Myelin Sheath

Enables faster transmission speed of neural impulses

Grey Matter

Abundant in cell bodies of neurons, unmyelinated

Schwann Cells

Wraps around axons, produces myelin cover

Nodes of Ranvier

Gaps in myelin sheath with sodium channels

Neurilemma

External myelin sheath on axons in PNS

Resting Membrane Potential

Sodium and potassium channels closed, -70mV

Stimulus Received

Some sodium channels open, Na+ ions move in

Depolarisation

Na+ channels open, inside becomes positively charged

Repolarisation

Sodium gates close, K+ ions move out, cell becomes more positive

Hyperpolarisation

- K+ ion channels are slow to close

- More K+ exit the cell than necessary

- Membrane potential is temporarily more negative than resting potential

- K+ ion channels close

- Resting membrane potential is restored by Na+/K+ ion pumps and natural movement of ions down a concentration gradient

Synapse

A junction where information is transmitted from one neuron to the next

Synapse Step 1

The nerve impulse (wave of action potential) reaches the axon terminal

Synapse Step 2

The action potential activates voltage-gated calcium ion channel in the axon terminal

Synapse Step 3

Calcium ions flood into the axon terminal of the presynaptic neuron

Synapse Step 4

The influx of calcium ions causes the vesicles (neurotransmitter filled) inside the axon terminal to move to the end plate. The vesicles purge (via exocytosis), the electrical signals from the action potential is converted into a chemical signal

Synapse Step 5

The neurotransmitters diffuse across the synaptic cleft

Synapse Step 6

The neurotransmitter binds to specific reception on the postsynaptic cleft on the neuron/muscle cell

Synapse Step 7

If on a neuron, this causes the ion channels to open and may stimulate a new action potential

Post Synapse

- Neurotransmitter joins receptor, instantly return to the synaptic cleft

- Some diffuse back into the presynaptic neuron

- Some are broken down by enzymes into components and reabsorbed by presynaptic neuron, more neurotransmitters formed with components

Sensory Neurons

Carry incoming information from sensory receptors to the brain and spinal cord

Motor Neurons

Carry outgoing information from the brain and spinal cord to muscles and glands

Interneurons

Neurons within the brain and spinal cord that communicate internally

Multipolar Neurons

Neuron with many extensions from the cell body

Unipolar Neurons

Neuron with a single projection from the cell body

Bipolar Neurons

Neuron with two projections (one axon/one dendrite) from the cell body